FORM TWO CHEMISTRY EXAMS SERIES

THE PRESIDENT’S OFFICE MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

COMPETENCY BASED SECONDARY EXAMINATION SERIES

 

                                                            CHEMISTRY   FORM TWO

TIME: 2 HOURS                                                                                                      NOVEMBER 2022

INSTRUCTIONS

1. This paper Consist of sections A, B and C with total of 10 questions 

2. Answer all questions in both sections 

3. All writings should be in blue/black ink 

4. All diagrams should be drawn in pencil 

5. Write your assessment number at the top right corner 

 

SECTION A (15 Marks)

1. For each of the items (i)-(x), choose the correct answer from among the given alternative and write its letter in the box provide.

 (i)   At room temperature in which substances are particles furthest apart?

A.   Water

B.    Sodium chloride

C.    Magnesium

D.   Hydrogen

E.    Hydrochloric acid

(ii)In the molecules CH4, HCI, and H20 which atoms use all of their outer shell imageelectrons in bonding? 

A. C and C! 

B. C and H 

C. a and H

D. H and O 

E. C and O

(iii)  In the laboratory one spoon of sugar was mixed with 200cm3 of water in a beaker to form .mixture

A.   Suspension

B.    Homogeneous

C.    Emulsionimage

D.   Miscible

E.    Heterogeneous

(iv)   The part of the Bunsen burner which controls the amount of air to support burning of the gas is

A. Jet

B.  Air hole

C.  Chimney 

D. Collar

E. Gas inlet

(v)        A certain mixture contained 280cm3 of alcohol and 300cm3 of water in the round bottomed flask, a form I student separated this mixture by fractional distillation process. Why?

A.   The two components have approximately the same volume

B.    The volume of water is less than the volume of alcohol

C.    The two component differ in boiling point

D.   The two component differ in volume

E.    Both are liquids at room temperatureimage

(vi)     Which change of matter occurs when water is kept at (zero) OOC?

A.   Water and vapour

B.    Liquid to gas

C.    Liquid to solid

D.   Water to steam

E.    Water to ice

 (vii)   A non - luminous flame is suitable for heating because

A.   It is very noisy

B.    It is very hot

C.    It has no soot

D.   It is very large

E.    It produce light

(viii) Calcium ion and calcium atom both have the same

A.   Size

B.    Physical properties

C.    Number of protons

D.   Electronic configuration

E.    Charge

(ix)     Class B fire can be extinguished by using each of the following

A.   Oxygen and nitrogen

B.    Carbondioxide and sand

C.    Carbondioxide and water

D.   Sand and water

E.    Hydrogen and neon

(x)..........................has the highest percentage abundance in air

A.   Nitrogen

B.    Oxygen

C.    Noble gas

D.   Water vapour

E.    Carbondioxide

2. Choose a word(s) from LIST B which matches the statement in LIST A and write its letter in the table provided below.

LIST A

LIST B

  1. For measuring specific volume of liquids and transfer into another flask.
  2. For measuring volume of liquids or gases
  3. For estimating or measuring roughly volume of a solution.
  4. For measuring volume of a liquids and dispensing them.
  5. It is used to make up solution to a total volume during an experiment
  1. Beaker
  2. Burette
  3. Measuring cylinder
  4. Measuring flask
  5. Measuring syringe
  6. Pipette
  7. Volumetric flask

SECTION B: (70 MARKS)

Answer all questions in the space provided for each question

3. (a) There is a room at Mtakuja secondary school, having only the following features

  • Large windows
  •  One door open inwards
  • Slippery floor
  •  No water supply

Does the room qualify to be used as a chemistry laboratory? Give three reasons

(b) Calculate the molar mass of

(i) A1203

(ii) Ca(OH)2

(iii) C02

4.(a) 

 (b)Element T has 19 electrons and mass number of 39, what is the; (i) Atomic number of element T?

(ii)  Number of neutrons of element T?.

(iii) Number of protons of element T?

(iv)  Write the nuclide notation of element T.....

(v)   Give the name of element T....

(c) image204J 206K 207L and AM are isotopes of element Q whose abundances are 2%, 24%, 22% and 52% respectively. Calculate the mass number A of an isotope M, given that the relative atomic mass of element Q is 207

(d)A form Il student from Pwani secondary school conducted an experiment as follows:He boiled a hydrated copper (Il) sulphate blue solution in a crucible until all water evaporated. Explain the changes observed during experiment.

5.  (a) Mr Juma was passing through in the laboratory and found a beaker on top of a table. He picked up the beaker with his bare hand, accidentally the beaker cut his finger since it was broken. Suggest four possible items of the first aid and their function to help Mr Juma.

Items 

Function

 

 

 (b) Give any three reasons to support that sodium chloride is a compound but Air is a mixture of gases.

Sodium chloride as a compound

Air as a mixture of gases

  1. ....
  2. ....
  3. ...

 

6.  (a) Write the name of the following compounds

(i) (NH4)2C03

(ii) N204 

 (iii) FeC13

(b) Calculate the oxidation state of the underlined element in the given compound 

(i) KC103

(ii) PbO2

(c) Write the chemical formula for the following compound

(i)    Calcium nitrate

(ii)    Zinc hydroxide

 (iii)   Copper (I) oxide

7.  (a) The diagram below shows the position of some elements in the periodic table. Study it and answer the questions below Note: The letters given are not the actual symbols of elements

(i) Identify the most reactive non-metal......................................................................

(ii) Give the formula of only one stable ion with an electronic configuration of 2:8

(iii) Which letter represents an element with a positively charged ion............

(iv) Explain the trends of atomic radii from X to U...........................

 

(v)  Identify elements represented by letters; W, Z, X and Y

  1. W................................
  2. Z....................................
  3. X.....................................
  4. Y.......................................

(vi) State group and period of element X

Element 

Group 

Period.

 

 

 

 (vii)  Explain why element V is stored under paraffin or Kerosine?  

image(b) A large number of Tanzania society are using firewood and charcoal as a source of fuel for domestic uses because it is very cheap and readily available but it has a negative effect in the environment. Assess the effect of such fuel in the environment

(c) (i) Coal and Petroleum are said to be a natural source of fuel. Explain why they are termed as non -renewable source of energy?

 (ii) State the law of conservation of energy

 (iii)   Petrol acid kerosene are liquid fuel. When burn they release energy, identify what type of energy they produce? (Give any two points)

8.  (a) Organic compound M composed of 52.2% of carbon, 13% of hydrogen and the rest is oxygen. If the vapour density of compound M is 23 (i) Find the percentage of oxygen in a compound M

 

(ii)Calculate the empirical formula of compound M

 (iii)                      Calculate the molecular formula of compound M

 

9. (a) Draw a well labelled diagram of laboratory preparation of a colorless gas which support combustion at room temperature (without heating)

(b) State the property that support hydrogen gas to be used in

(i)  Production of margarine

 (ii) Making oxy — hydrogen flame.

(iii) Production of water gas

 (iv)  Filling of weather balloons......................

SECTION C: (15 MARKS)

10. (a) Four experiment were conducted using chemical A, B, C and D on different materials, the results were given as indicated below. You are required to write the correct terminology which suits each of the results given and draw the chemical warning signs which goes with it

(i)    When chemical A was poured on the wool it completely damage the surface of the wood

(ii)When chemical B was poured on the small fire, it found burst and turning a bigger fire

(iii) When chemical C was brought near the skin of some one, he started to imagecomplain that his skin was itching

(iv)  When chemical D was exposed on air sudden blust accompanied with light occurred.

Terminology

Terminology

Chemical warning sign

  1.         Chemical A is
  2.       Chemical B is
  3.    Chemical C is
  4.     Chemical D is

 

 

(b) List down any two importance of changing states of matter in our daily life

 

 

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 126

PRESIDENT’S OFFICE

REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

FORM TWO EXAMINATION – SEPTEMBER 2022

032     CHEMISTRY

TIME: 2:30 HOURS

INSTRUCTIONS

  1. This paper consists of sections A and B with a total of TEN (10) questions
  2. Answer all questions in the space provided.
  3. All writing must be in black or blue ink except for diagrams which must be in pencil
  4. Cellular phones and any unauthorized materials are not allowed in the examination room
  5. Write your Examination Number on every page of your answer booklet(s)
  6. The following constants may be used

Zn= 65, X =32, O=16

 

SECTION A (15 Marks)

Answer all questions in this section

  1. For each of the items (i) - (x), choose the correct answer from among the given alternatives and write its letter beside the item number in the bracket provided.

 

  1.        When burning a fuel produces  blue color it means there is
  1. Adequate supply of oxygen with production of soot
  2. In adequate supply of oxygen with production of soot
  3. Adequate supply of oxygen with production of less heat
  4. Adequate supply of oxygen with production of more heat ( )

 

  1.       Which of the following is an agricultural chemical products made by the application of chemistry?
  1. Drugs B. Pesticides  C. Clothes  D. Cement ( )

 

  1.    Which of the following is NOT among the composition of air?
  1. Noble gases B. Hydrogen  C. Carbon dioxide    D. Nitrogen ( ) 

 

  1.   Which one of the following sets of laboratory apparatus are used for measuring volume of liquids
  1. Conical flask, measuring cylinder and test tube
  2. Burette, pipette and measuring cylinder   ( )
  3. Volumetric flask, water though and burette
  4. Gas jar, measuring cylinder and pipette

 

  1.      The following are the characteristic of ionic compound
  1. They are easily vaporized
  2. They are easily dissolved in organic solvent
  3. Conduct electricity when in solution or molten
  4. Usually exist as liquid or gas at room temperature

 

  1.   Which of the following is a symbol of silver ion
  1. Ag  B. S  C. Ag+  D. Si   ( )

 

  1.  What is proton, electron and atomic number AI    ( )
  1. 13,13,13  B. 13,11,13  C. 13,12,13  D. 13,13,11

 

  1. Which state is involved when drying wet clothes?
  1. Liquid to solid B. Gas to liquid C. Liquid to gas  D. Solid to gas( )

 

  1.    The components of fire triangle are ;
  1. Oxygen, fuel and heat  C. Oxygen, heat and hydrogen ( )
  2. Oxygen, nitrogen and heat D. Oxygen, carbon dioxide and fuel

 

  1.      Which group and period does the element with 14 electrons belong?
  1. Group II and period 3  C. Group III and period 3 ( )
  2. Group IV and period 3  D. Group II and period 4

 

 

  1. Match the descriptions in List A with the corresponding in List B by writing the letter of the correct response beside the item number in the answer booklet provided

LIST A

LIST B

  1. A series of investigation
  2. A tentative explanation
  3. A statement that identifies an event, fact or situation
  4. A statement of how the results relate to hypothesis
  5. A step in which the researcher explain the results
  1. Conclusion
  2. Data analysis
  3. Data collection
  4. Hypothesis
  5. Observation
  6. Experimentation
  7. Problem identification

 

 

Answers

LIST A

i

ii

iii

iv

v

LIST B

 

 

 

 

 

 

SECTION B (70 Marks)

Answer all questions in this section

 

3(a) Fill the blanks 

  1. The techniques used to separate serum from blood samples is called _________________________
  2. The insoluble substances remain in a filter paper during filtration are termed as ___________________________
  3. Boiling points of substance reflect the strength of __________________
  4. The sub atomic particles of an atom are ____________________ and _____________________
  5. Solar energy is example of _______________________resources

 

 

  1. (b) Suggest the best method of separating the following mixture
  1. Alcohol and water  _______________________________________________________________________________________________________________________________________________________________________________________
  2. Sodium chloride and water _______________________________________________________________________________________________________________________________________________________________________________________
  3. Green solution from leaves   _______________________________________________________________________________________________________________________________________________________________________________________
  4. Sand from rice  _______________________________________________________________________________________________________________________________________________________________________________________

 

  1. Iron fillings and powder calcium carbonate  _______________________________________________________________________________________________________________________________________________________________________________________

 

 

 

 

  1. (a) Complete the following table

 

Class of fire 

Materials 

Fire extinguisher 

Chemical composition of extinguisher 

CLASS A

 

 

Ordinary tap water pressurized by air 

 

Flammable liquids 

Dry powder extinguisher 

 

CLASS C

 

Sand bucket 

 

 

 

Metal 

 

Sulphuric acid and sodium hydrogen carbonate 

CLASS E

 

 

 

Protein and fluoro protein 

(b) With one example explain each of the following

  1. Alkali earth metals __________________________________________________________________________________________________________________________
  2. Metalloids  __________________________________________________________________________________________________________________________
  3. Transition metals  __________________________________________________________________________________________________________________________
  4. Why are noble gases stable? __________________________________________________________________________________________________________________________
  5. Why covalent compound do not conduct electricity  __________________________________________________________________________________________________________________________

 

  1. (a) What is destructive distillation

__________________________________________________________________________________________________________________________________________

(b) Mention five (5) procedures of preparing charcoal from the method mentioned in 

      5(a) above 

  1. ________________________________________________________
  2. ________________________________________________________
  3. ________________________________________________________
  4. ________________________________________________________
  5. ________________________________________________________

 

  (c) Mention four (4) steps of lightning a Bunsen burner

 

  1. ________________________________________________________
  2. ________________________________________________________
  3. ________________________________________________________
  4. ________________________________________________________
  5. ________________________________________________________

 

  1. An atom of element X having atomic number 11 combines with an atom of element Z having atomic number 17 to form a compound
    1. Write the formula of the compound and state the type of bond formed in the compound

 

 

 

 

  1. Give four properties of compound in 6(a)
  1. ____________________________________
  2. ____________________________________
  3. ____________________________________
  4. ____________________________________
  5. ____________________________________

 

  1. (a) Write the chemical symbols for beryllium, boron, neon, nitrogen and phosphorus
  1. ____________________________________
  2. ____________________________________
  3. ____________________________________
  4. ____________________________________
  5. ____________________________________

 

(b) You are provided with a compound composed of 40.5% zinc. 19.6% sulphur and 

     39.9% oxygen. Calculate the molecular and empirical formula. If it’s molecular 

     mass is 161

 

 

 

 

 

 

 

  1. (a) By giving one reason, explain the following facts
  1. During laboratory preparation of oxygen gas, little manganese dioxide is added to hydrogen peroxide.

__________________________________________________________________________________________________________________________

 

  1. Fish can obtain oxygen for respiration although spend their life in water

_________________________________________________________________________________________________________________________ 

  1. Oxygen gas can be used for welding activities although it does not burn

__________________________________________________________________________________________________________________________

      (b) Which property enables the use of hydrogen gas in 

  1. Fueling __________________________________________________
  2. Manufacturing of margarine _________________________________

 

  1. Give two domestic uses of oxygen gas
  1. ________________________________
  2. ________________________________

 

  1. (a) Define the following terms

 

  1. Water treatment __________________________________________________ ________________________________________________________________
  2.            Water purification  _____________________________________________ ________________________________________________________________

(b) List down four (4) economic uses of water 

  1. ____________________________________
  2. ____________________________________
  3. ____________________________________
  4. ____________________________________

(c) What are the importance of water treatment and purification? Give two (2) reasons 

__________________________________________________________________________________________________________________________________________

SECTION C (15 Marks)

 

  1. Briefly explain five methods used to prevent rusting and give example for each

 

Page 1 of 6

 

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 111

THE PRESIDENT’S OFFICE

MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

COMPETENCY BASED SECONDARY EXAMINATION SERIES

CHEMISTRY TERMINAL EXAMINATION

FORM TWO-2022

Time: 2:30Hours

Instructions.

  1. This paper consists of section A, and B with a total of 10 questions
  2. Answer all questions in spaces provided.
  3. Section A carries 20 marks, section B 80 marks.
  4. All answers should be written in the spaces provided.
  5. All communication devices, calculators and any unauthorized material are not allowed in examination room.
  6. Write your number on every page of your answer booklet.
  7. The following atomic masses may be used: H=1, N=14, O=16, S=32

 SECTION A (20 Marks)

 Answer All questions in this section.

  1. For each of the items (i)-(x), choose the correct answer from the alternatives given.
  1. The valency of an element with atomic number 10 is;
  1. 2      B. 3       C. 0    D. 1 
  1. How many protons, neutrons and electrons are there in an atom represented by the symbol

Protons   Neutrons  Electrons 

  1. 39  19  20
  2. 19  39  20
  3. 20  19  20
  4. 19  20  19
  1. Separation of a mixture by fraction all distillation is possible if the mixture constituents differ in their;
  1. Boiling points   B. Melting points   C. Freezing points    D. Vapourizing points
  1. When element T of Group 1 combines with element X of Group VI, the formula of the compound formed is;
  1. T2X    B. X2T     C. TX2     D. XT
  1. Saturated solution is one which;
  1. Contains more solute undissolved  at a given temperature
  2. Has a large amount of solvent at a given temperature
  3. Contains a little solute at a given temperature
  4. Will take no more of solute at a given temperature
  1. The most abundant element on the earth is;
  1. Carbon     B. Iron    C. Nitrogen    D. Oxygen
  1. Petrol is an example of;
  1. Ionic substance   C. Flammable substance 
  2. Irritating substance  D. Corrosive substance 
  1. Domestic utensils made of iron undergo rusting when exposed to;

A.  Air and fire   B. Air and oil   C. Air and water   D. Water and oil 

  1. The chloride iron (Cl-) differs from chlorine atom because chloride ion has;

A.  Loss electrons    B. Less protons   C. More electrons   D. More protons 

              x.   Which of the following chemical species have the same number of electrons? 

                    A. Cl, Be, He and O2-       B. K+, Ca2+, Cl- and Ar  

                    C. Na+, Mg2+, Al3+ and Li   D. O2-, F-, S2- and Cl- 

 

i

ii

iii

iv

v

vi

vii

viii

ix

x

 

 

 

 

 

 

 

 

 

 

 

SECTION B: 20 MARKS

  1. You are provided with two lists A and B. Choose a words from list B which matches the statement or phrase in List A and write its letter in the table provided below;

LIST A

LIST B

  1. Increases from left to right across the period in the periodic table.
  2. Method used to extract oil from nuts.
  3. Addition of hydrogen to a substance or removal of oxygen from a substance.
  4. Substance which can burn your skin.
  5. Immiscible liquids

 

  1. Biogas
  2. Electronegativity
  3. Solvent extraction
  4. Reduction
  5. Electron sharing
  6. Electrostatic forces
  7. Corrosive
  8. Irritating
  9. Water and Kerosene
  10. Isotopy
  11. Data analysis
  12. Solution extraction
  13. Mortar and pestle
  14. Desiccator
  15. Painting
  16. Catalyst

 

(b) 

SECTION B: 80 MARKS

  1. (a) What do you understand by the following terms?
  1. First Aid ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
  2. First Aid Kit ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(b) Name four components which can be found in First Aid Kit; 

  1. …………………………………………………………………………………………………………
  2. …………………………………………………………………………………………………………
  3. …………………………………………………………………………………………………………
  4. …………………………………………………………………………………………………………

(c) Why is it important to provide First Aid to an injured person? Give four reasons;

  1. …………………………………………………………………………………………………………
  2. …………………………………………………………………………………………………………
  3. …………………………………………………………………………………………………………
  4. …………………………………………………………………………………………………………
  1. (a) For each of the following classes of fire, state the burning material(s);
  1. Class A fire ……………………………………………………………………………………………
  2. Class B fire ……………………………………………………………………………………………
  3. Class C fire ……………………………………………………………………………………………

(b) Fire can be prevented by; 

  1. …………………………………………………………………………………………………………
  2. …………………………………………………………………………………………………………
  3. …………………………………………………………………………………………………………
  4. …………………………………………………………………………………………………………
  1. (a) By giving one example, define the following terms;
  1. Suspension ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
  2. Chromatography ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(b) Briefly explain the following ways of preventing rusting. 

  1. Electroplating ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
  2. Galvanizing ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(c) Write the chemical symbols for the following elements; 

  1. Silver ………………………..
  2. Iron ………………………….
  3. Aluminium …………………….
  1. (a) If a mixture of manganese (IV) oxide, MnOwith potassium chlorate, KClO3 is treated, which of

     the two compounds will produce oxygen? 

  1. …………………………………………………………………………………………………
  2. Why? ………………………………………………………………………………………….

(b) Calculate the oxidation number of the underlined elements;

  1. NH4+
  2. SO42-
  3. CUSO4
  4. FeCl2
  1. (a) List down four assumptions of the Dalton’s Atomic Theory;
  1. ……………………………………………………………………………………………………
  2. …………………………………………………………………………………………………
  3. …………………………………………………………………………………………………
  4. …………………………………………………………………………………………………

(b) Write a chemical formula for each of the following compounds;

  1. Water …………………………………………………………..
  2. Potassium chloride ………………………………………………
  3. Magnesium oxide ………………………………………………….
  4. Calcium hydroxide ……………………………………………….

(c) (i) What do you understand by the term “Chemical warning signs”? ……………………………………………………………………………………………………………

  (ii) Draw the chemical warning sign that represents; 

HARMFUL OR IRRITANT 

TOXIC 

FLAMMABLE 

 

 

 

 

 

 

 

 

 

 

 

 

  1. Study the periodic table below;

 I                                                                                        VIII

                                    II         III         IV         V         VI        VII

 

C

A

 

D

 

 

 

 

 

E

 

F

 

 

 

 

 

G

 

H

 

 

 

 

J

 

 

 

 

 

 

 

Use the letters shown in the periodic table above to indicate; 

  1. Elements with zero valency …………………………
  2. The lightest atom. …………………………………….
  3. The alkaline earth match. ……………………………………
  4. An element with electronic configuration of 2: 8: 1. …………………………..
  5. Give the names of elements represented by the mentioned letters A, B, C and D. ……………………………………………………………………………………
  6. Give the name of J as an element. ………………………………………………….
  7. Write the electronic configuration of J. …………………………………………….
  8. What type of a bond can be formed when element J combined with element H? ……………………………………………………………………
  9. What type of a bond can be formed when an element H combines with an element H …………………………………………………………………
  1. (a) What is air? ………………………………………………………………………………………………………………………………………………………………………………………………………………………….

(b) Mention the composition of air with their percentage composition; 

COMPOSITION 

PERCENTAGE (%) COMPOSITION 

 

  1. ……………………………………..
  2. ……………………………………..
  3. ……………………………………..
  4. ……………………………………...

 

……………………………………..

……………………………………..

……………………………………..

           ……………………………………...

 

(c) Give four reasons why air is a mixture. 

  1.  ……………………………………………………………………………………………………
  2. …………………………………………………………………………………………………
  3. …………………………………………………………………………………………………

                 iv       …………………………………………………………………………………………………

  1. (a) Give the method used to separate the following mixtures;
  1. Kerosene and water …………………………………………………………………………………
  2. Alcohol (ethanol) and water ………………………………………………………………………..
  3. Iron fillings and sand ……………………………………………………………………………….
  4. Iodine crystals and table salt ……………………………………………………………………….

(b) Water is a chemical compound? Give four reasons to support this fact. 

  1. ………………………………………………………………………………………………………
  2. ……………………………………………………………………………………………………….
  3. ……………………………………………………………………………………………………….
  4. ………………………………………………………………………………………………………

 

 

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 97

THE PRESIDENT’S OFFICE

MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

COMPETENCY BASED SECONDARY EXAMINATION SERIES

CHEMISTRY MID TERM EXAMINATION

FORM TWO- MARCH/APRIL-2022

Time: 2:30Hours

Instructions.

  1.  This paper consists of section A, and B with a total of 10 questions
  2. Answer all questions in spaces provided.
  3. Section A carries 20 marks, section B 80 marks.
  4. All answers should be written in the spaces provided.
  5. All communication devices, calculators and any unauthorized material are not allowed in examination room.
  6. Write your number on every page of your answer booklet.
  7. The following atomic masses may be used: H=1, N=14, O=16, S=32

 SECTION A (20 Marks)

 Answer All questions in this section.

 

  1. Write the letter of the best answer in each of the following multiple choice questions. Use the table below.
  1. What best knowledge can be used by industrialists to manufacture chemicals
  1. Methods of separating mixtures
  2. Debate on drug abuse
  3. Campaigns on elections
  4. Labeling apparatus for experiments

 

  1. How students can protects him against injuries and deaths in a school laboratory?
  1. To walk very slowly along the corridors of a laboratory
  2. To study ways of offering first AID
  3. To observe laboratory rules
  4. To study uses of products from manufactures

 

  1. Which one of the following pair of chemicals is used to swab clean fresh cuts and wounds?
  1. Methylated spirit and iodine tincture
  2. Petroleum jelly and copper sulphate
  3. Milk of magnesia and sodium chloride
  4. Ethanoic acid and calcium hydroxide

 

 

  1. What is the common use of the following hardware laboratory equipments, a pair of tongs, forceps, clamp and stand, sugar tongs
  1. To determine mass of the chemicals
  2. To burn chemicals
  3. To pick solid chemicals
  4. To hold objects

 

  1. Which is the appropriate warning sign to be pasted on a container that has a chemical which is a source of oxygen
  1. Flammable
  2. Explosive
  3. Oxidizing
  4. Corrosive

 

 

  1. Which set of apparatus seems to belong in a group of glassware
  1. Thermometer, crucible and lid, white tile clamp and stand
  2. Volumetric flask, reagent bottle, beehive shelf, pipe clay triangle
  3. Separating funnel, burette, pipette, conical flask
  4. Beakers, cork borer, Bunsen burner, glass rod

 

 

  1. What is the name of the constant temperature of a substance changing its state from liquid to solid?
  1. Melting point
  2. Boiling point
  3. Freezing point
  4. Sublimation point

 

  1. Which process changes a gas directly to solid without the liquid state?
  1. Condensation
  2. Sublimation
  3. Solidification
  4. Non of the above

 

 

  1. Which of the following process is not a chemical change?
  1. Soaring of  milk
  2. Burning of paper
  3. Decomposition of a compound by heating
  4. Separating mixtures

 

  1. Substances which are poor conductors of heat and electricity. What is best idea one can give about the above statement?
  1. They are metals
  2. They are non metals
  3. They are elements
  4. They are mixtures

 

 

  1. (a) Match the following items by writing the letter against numbers for the best matches. Use the table below

 

LIST A

LIST B

  1. Sublimate
  2. Distillate
  3. Filtrate
  4. Chromatogram
  5. Distillation

 

  1. Liquid obtained after filtration
  2. Solid that remains after filtration
  3. Solid that cools after sublimation
  4. Lines obtained during colour separation
  5. Liquid obtained after distillation
  6. Separating miscible liquids
  7. Obtaining solid from solution
  8. Water vapour that condences

 

 

       (b) Fill in the following blanks spaces to make meaningful statement

  1. …………………………………… is used to separate liquids mixtures of different densities which do not mix. The liquid which comes out first is found at the …………………………………… of the funnel
  2. A reagent bottle is used to store chemical ……………………………… and the label on the side of the bottle carries the ……………………….of the chemical in the bottle
  3. Hydrogen gas is a ………………………………… causing substance suck substances are called ……………………………………
  4. …………………………………… is a small special box which contains items used to offer …………………………………………….
  5. Detergents are examples of …………………………………pollutants. They interfere with …………………………….balance. B.O.D

 

SECTION B (80 Marks)

Answer all questions in this section.

 

  1. List four (4) chemical properties of oxygen
  2. Write three (3) common methods of preparations of oxygen in the laboratory
  3. What is chemical test for oxygen gas?
  4.  List any four (4) uses oxygen gas in our daily life
  1. Write a word chemical equation to show the decomposition of hydrogen  peroxide in the presence of manganese (IV) oxide.
  2. Why oxygen gas is collected over water?
  3.  Respiration and burning are similar process in some ways and difference  process in other ways. Give two differences between them.

10. a) State any four laboratory rules

(b) Consider the diagram below and then answer the questions that follows:

slide_13

Label parts 

  1. A ………………………………………………………………………………………
  2. B…………………………………………………………………………………………
  3. C…………………………………………………………………………………………
  4.  D ………………………………………………………………………………………
  5.  E ……………………………………………………………………………………………..

 

 

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 85

THE PRESIDENT’S OFFICE

MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

COMPETENCE BASED  SECONDARY EXAMINATION SERIES

ANNUAL  EXAMINATION

FORM TWO-2021

                                        CHEMISTRY

       032                                                

TIME: 2:30 HOURS                                                     November, 2021

image

Instructions

1.This paper consists of sections A and B with a total of ten (10) questions.

2.Answer all questions in the spaces provided.

3.All writings must be in blue or black ink except drawings which must be in pencil.

4.All communication devices and calculators are not allowed in the examination room.

5.Write Your Examination Number on the top right of every page.

6.The following atomic masses may be used.

H = 1, C = 12, O = 16, N = 14, S = 32, Zn = 65, Cl = 35.5, Na = 23.

FOR EXAMINER’S USE ONLY

QUESTION

NUMBER

SCORE

EXAMINER’S INITIALS

1



2



3



4



5



6



7



8



9



10



TOTAL



CHECKER’S INITIALS


SECTION A: (20 Marks)

1.Write down the letter corresponding to the most correct answer in the box provided for each item.

(i) How many protons, neutrons and electrons are there in an atom represented by image?

B.17                    18                    17

C.18                    17                    35 

D. 17                      35                 18.

(ii) Which of the following methods is used to separate salt from sea water?

A.Filtration

B.Decantation

C.Decantation

D.Fractional distillation.

(iii)Which of the following warning signs is likely to appear on a gallon containing methylated spirit in the laboratory?

A.Irritant

B.Flammable

C.Oxidant D. Explosion.

(v)Hydrogen peroxide image(iv) X + water. “X” represents _________

A.Oxygen

B.Hydrogen

C.Nitrogen 

D. Carbondioxide.

(vi)If a Bunsen burner produces much soot, which is the correct conclusion?

A.The air hole is closed

B.The burner gas jet is big

C.The air hole is fully opened

D.The gas supply is poor.

(vii)Which of the following is the list of group (II) element?

A.Sodium and magnesium

B.Calcium and carbon

C.Magnesium and calcium

D.Boron and Beryllium.

(viii)Element M of group I combines with element X of group VI, the formula of the compound formed when M combines with X is:

A.MX2

B.MX6

C.X2m

D.M2X.

(ix)The pair of elements which is most likely to form a covalent bond when reacted together is:

A.Carbon and chlorine

B.Aluminium and oxygen

C.Magnesium and oxygen

D.Sodium and chlorine.

(x)One of the following can distinguish hydrogen gas from other gases: A. It burns and supports combustion

B.It is colourless and ordourless C.It gives a smell of a rotten egg

D.It burns with pop sound.

(xi)The following sentences suggest that air is a mixture, except:

A.Its components can be separated physically

B.Its composition varies from one place to another

C.Its properties depends on individual gases

D.Its formation requires absorption or reabsorption of heat.

2.(a) Choose a word(s) from list B which matches the statement or phrases in list A and   write its letter in the space provided.

LIST A

LIST B

(i)Factors that can be manipulated to get desired results

(ii)A factor that is kept constant

(iii)Scientist’s best possible answer

(iv)Statement of how the results related to hypothesis

(v)First step in scientific method of studying a problem

A.Controlled variable

B.Hypothesis

C.Observation

D.Conclusion

E.Independent variable

F.Identification of a problem

G.Experimentation

H.Data analysis

Answer:

List A

(i)

(ii)

(iii)

(iv)

(v)

List B






2.   (b) Fill in the blanks below with the correct words.

(i)A candle flame is not good for glass ware because _____________________

(ii)A catalyst used for the production of oxygen gas from hydrogen peroxide is _______________________

(iii)A sudden unexpected occurrence that destroy properties and cause injury is called __________________________

(iv)It is used as fuel in rockets due to its lightness _________________________

(v)Blockage of the upper part of airway by food or other objects is called 

                            ________________________________

SECTION B: (80 Marks)

Answer all questions in this section

3. (a)  What is fuel?

___________________________________________________________________________

_____________________________________________________________________

          (b) (i)       State four types of fuels used by many Tanzanians:

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

                                                                                                        @ 1 mark = 04 marks

(ii) Why do you think many Tanzanians prefer to use the mentioned sources in 3b(i) above? Give two best reasons.

_______________________________________________________________

_______________________________________________________________

                                                                                                        @ 02 marks = 04 marks

4. You are provided with the following materials from chemistry laboratory:

Apparati: Thistle funnel, delivery tube, beehive self, trough, gas jar, flat bottomed flask with its coke. 

      Chemicals:Water, zinc granules, dilute hydrochloric acid.

(a)What chemical substance can be prepared using the materials mentioned above?

_____________________________________________________________________

(b)Draw the diagram showing how you could arrange the Apparati above in order to prepare a chemical substance you mentioned in 4(a) above. 05 marks

(c)How can the products mentioned in 4(a) above be collected?____________________________________________________________________

____________________________________________________________________

                                                                                                                  02 marks

    (d) Give at least three (3) uses of the product you mentioned in 4(a) above based on its             properties.

(i)______________________________________________________________

(ii)______________________________________________________________

(iii)______________________________________________________________

5. (a) What should you do immediately if:

(i)The piece of broken beaker cuts your finger

_______________________________________________________________

(ii)Chemicals splash on your face

_______________________________________________________________

(iii)Your shirt has caught fire

_______________________________________________________________

(iv)Your fellow student swallows unknown chemical substance thinking that it was water

_______________________________________________________________

                                                                                                @ 02 marks = 08 marks

    (b) Why do you think first aid is an important thing? Give two points:

(i)___________________________________________________________

(ii)___________________________________________________________

                                                                                                @ 01 mark = 02 marks

6.  (a)  (i)         A table salt is a common name for the compound with the formula NaCl. 

                          Write the systematic name for the table salt

_______________________________________________________________

_______________________________________________________________

                                                                                01 mark                                               

(ii) Briefly describe why molecular formula better preferred than empirical formula is_______________________________________________________________ _______________________________________________________________

_______________________________________________________________

                                                                                            02 marks

(b)   A compound consists of 27% sodium, 16.5% nitrogen and 56.5% oxygen by mass. If its molecular mass is 85g, find:

(i)Its empirical formula                                                  05 marks

(ii)Molecular formula                                                      02 marks

7.  (a)  Briefly explain the following terms: 

(i)Periodicity

_______________________________________________________________

_______________________________________________________________

(ii)Electronegativity

_______________________________________________________________

_______________________________________________________________

(iii)Ionization energy

_______________________________________________________________

_______________________________________________________________

(iv)Atomic radii/size.

_______________________________________________________________

_______________________________________________________________

                                                                                                        @ 01 mark = 04 marks

(b)  Why are certain elements in the period table referred to as metalloids? Give two examples of such elements:

Reason: ____________________________________________________________   

                                                                                                                02 marks

Example:

(i)_____________________________________________________________

(ii)_____________________________________________________________

                                                                                                  @ 00 ½ mark

(c)  Element X has atomic number of 19 and neutron number 20. Write down its:

 (i)        Electronic configuration

                               ______________________________________________________________

                                                                                                                01 mark

                (ii)       Mass number                                                              02 marks

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

8.(a)    (i)     Differentiate combustion from rusting.

     _______________________________________________________________

     _______________________________________________________________

 (ii)    Explain why cars and corrugated iron sheets in coastal areas like Dar es

Salaam, Tanga and Zanzibar get rust more quickly than in other cities of

    Tanzania like Mbeya, Mwanza and Arusha?                         02 marks

_______________________________________________________________

 _______________________________________________________________

(b)Explain how you can put off each of the following types of fire

(i)A fire started by petrol in a container                             02 marks

 _______________________________________________________________

  _______________________________________________________________

(ii)A fire started by a short circuit in an electric wire                     02 marks

 _______________________________________________________________

(iii)A fire caused by a burning magnesium metal                02 marks

 _______________________________________________________________

9.(a) With an example give the meaning of the following terms as applied in Chemistry:

(i)A radical                                                                            02 marks

_______________________________________________________________

_______________________________________________________________

(ii)Oxidation state                                                                     02 marks_______________________________________________________________ _______________________________________________________________

(b)Find the oxidation numbers of the following underlined elements:

(i)        Na        01mark                                                (ii)      HNO3     01mark

                (iii)      H2SO4       01mark                                         (iv)     SO32-          01mark

 (c)       Draw diagrams showing the electron transfer in the formation of MgCl2.

10.  (a)     Differentiate the following terms:

(i)An element and an atom

__________________________________________________________________

__________________________________________________________________

(ii)A compound and a mixture

__________________________________________________________________

__________________________________________________________________

(b)        Melting of ice and burning of papers are two processes that happen almost daily in our life.

(i)Identify the two actions as being physical or chemical change.

Ice melting __________________________________________________ 

Paper burning ________________________________________________

(ii)Mention two significant things that happen when the paper is burnt:

_______________________________________________________________ _______________________________________________________________

 (c)       What are the names of elements represented by the following symbols?

(i)K _________________________________________________________

(ii)S _________________________________________________________

(d)       Why some elements have their symbols written in one letter while others have   two letters? (e.g. N and Na) 


LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 74

THE PRESIDENT’S OFFICE

MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

COMPETENCY BASED SECONDARY EXAMINATION SERIES

CHEMISTRY MID TERM EXAMINATION

FORM TWO- AUG/SEPT 2021

 Time: 2:30Hours

Instructions.

  1.                          This paper consists of section A, and B with a total of 10 questions
  2.                          Answer all questions in spaces provided.
  3.                          Section A carries 20 marks, section B 80 marks.
  4.                          All answers should be written in the spaces provided.
  5.                          All communication devices, calculators and any unauthorized material are not allowed in examination room.
  6.                          Write your number on every page of your answer booklet.
  7.                          The following atomic masses may be used: H=1, N=14, O=16, S=32

 SECTION A (20 Marks)

 Answer All questions in this section.

  1.                For each of the items (i)-(x), choose the correct answer from the alternatives given.


(i) The elements which are found in group VIII of the periodic table are known as:

  1.              Metals
     
  2.               Noble gases
  3.               Non - metals
  4.              Right elements


(ii) Isotopes are atoms which have:

  1.              Different mass number
  2.               Different number of electrons
  3.               Different number of protons
  4.              The same number of neutrons

(iii) The elements which are found in group VIII of the periodic table are known as:

  1.              Metals
     
  2.               Noble gases
  3.               Non - metals
  4.              Right elements

(iv) The process used to separate a mixture of salt and water is:

  1.              Evaporation
  2.               Filtration
  3.               Simple distillation    
  4.              Sublimation


(v) Saturated solution is one which:

  1.              Contains more solute undissolved at a given temperature.
  2.               Will take no more of solute at a given temperature.
  3.               Contains a little solute at a given temperature.
  4.              Has a large amount of solvent at given temperature.

 (vi) Which of the following electronic configurations are of metals?

  1.              2:8:8:1 and 2:8:8:7
  2.               2:8:3 and 2:8
  3.               2:8:8:1 and 2:8:3
  4.              2:8:6 and 2:8:8:7

(vii) One isotope of an element has atomic number A and mass number M. How many neutrons are contained in the nucleus of its atom?

  1.              M
  2.               A
  3.               A - M
  4.              M - A

(viii) The total number of protons and neutrons in the nucleus of an atom is called:

  1.              Valency number  
  2.                Atomic number
  3.                Molecule number    
  4.               Mass number

(ix)  Oxidation may be defined as:

  1.              Loss of hydrogen by a substance
  2.               Gain of hydrogen by a substance
  3.               Reaction in which oxygen is lost
  4.              Reaction in which electrons are increased

(x) Moving across a period in the periodic table,

  1.              Electro negativity decreases
  2.               Electro negativity increases
  3.               Metallic property increases
  4.              Electro positivity increases 

2. (a)Match each item in List A with a correct response in List B by writing the letter of the correct response below the corresponding item number in the table provided.

LIST A

LIST B

  1. Energy needed to remove an electron from atom
  2. The most electronegative element
  3. Positive charged particle
  4. Simplest element
  5. Used to test presence of water
  1.              Free energy
  2.               Helium
  3.               Anion
  4.              Cation
  5.               Hydrogen
  6.                Copper sulphate
  7.              Ionization energy
  8.              Fluorine
  9.                 francium


(b) Answer the given questions by writing the correct answer in the blank spaces provided.

  1. Has both metallic and non metallic properties………………………
  2. A gas that can undergo sublimation………………………..
  3. Name given to group seven elements which means salt producer…………………..
  4. An example of renewable fuel from organic matter…………………..
  5. Separation of colored substances…………………..

3. Briefly explain five characteristics to be considered when looking for a good fuel.

4.(a) During preparation of Hydrogen gas by the reaction between dilute Hydrochloric acid and Zinc granules, the granules slowly dissolve in acid to form solution X. 

(i) Name solution X .........

(ii) Write the chemical formula of X . . . . . . 

(b) How can hydrogen gas be tested?image

(c) Mention four (4) chemical properties of hydrogen gas.

(d) List three (3) uses of Hydrogen gas.

5.Outline six common apparatus used in the laboratory preparation of oxygen gas using hydrogen peroxide.

(b) Outline four uses of oxygen in everyday life situation.

6.(a) Define the following terms:

(i)Valency

(ii)Oxidation state

(iii) Anion

(iv)Cation

(b) Calculate the oxidation state of the underlined elements in the following radicals:

(i) NH4+

(ii) SO42+

(iii) CLO3-

(c) A compound consists of 40% carbon, 6.67% hydrogen and 53.33% oxygen. If its relative molecular mass is 60, calculate the following:

(i)Empirical formula

(ii)Molecular formula

7.(a) Define the following terms:

(i)Oxidation state 

(ii)An element .......„

(iii)A compound

(iv)Fainting 

(b)Write the chemical formula for each of the following compounds:

(i)Sodium sulphate 

(ii)Sodium chloride .. 

(iii)Calcium nitrate ......... (iv) Calcium oxide . 

8.State two chemical properties of water.


(b) Calculate the molar mass of each of the following compounds:

(ii) NaHC03                        (iii) Fe203 

9.Define the following terms:

(i)Empirical formula .........

(ii)Molecular formula .........

(b)A compound consists of 85.7% carbon and 14.3% hydrogen by mass. If its relative molecular mass is 56, calculate:

(i)Empirical formula.

(ii)Molecular formula.

10.(a) Study the following periodic table and then answer the questions that follow:

(i) Name elements named by the following letters: S, W, X, Z

(ii) Write the electronic configuration for the elements represented by the following letter.

10.(b) Study the experiment diagram below and answer the questions that follow.

(i)What happens to the copper (Il) oxide during the experiment?

(ii)What happens to the two pieces of cobalt paper? (iii) Write a word equation for the reaction.

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 65

THE PRESIDENT’S OFFICE

MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

COMPETENCY BASED SECONDARY EXAMINATION SERIES

CHEMISTRYTERMINALEXAMINATION

FORM TWO-2021

 Time: 2:30Hours

Instructions.

  1.              This paper consists of section A, and B with a total of 10 questions
  2.              Answer all questions in spaces provided.
  3.              Section A carries 20 marks, section B 80 marks.
  4.              All answers should be written in the spaces provided.
  5.              All communication devices, calculators and any unauthorized material are not allowed in examination room.
  6.              Write your number on every page of your answer booklet.
  7.              The following atomic masses may be used: H=1, N=14, O=16, S=32

 SECTION A (20 Marks)

 Answer All questions in this section.

  1. For each of the items (i)-(x), choose the correct answer from the alternatives given.
  1. The valency of an element with atomic number 10 is;
  1. 2      B. 3       C. 0    D. 1 
  1. How many protons, neutrons and electrons are there in an atom represented by the symbol

Protons   Neutrons  Electrons 

  1. 39  19  20
  2. 19  39  20
  3. 20  19  20
  4. 19  20  19
  1. Separation of a mixture by fraction all distillation is possible if the mixture constituents differ in their;
  1. Boiling points   B. Melting points   C. Freezing points    D. Vapourizing points
  1. When element T of Group 1 combines with element X of Group VI, the formula of the compound formed is;
  1. T2X    B. X2T     C. TX2     D. XT
  1. Saturated solution is one which;
  1. Contains more solute undissolved  at a given temperature
  2. Has a large amount of solvent at a given temperature
  3. Contains a little solute at a given temperature
  4. Will take no more of solute at a given temperature
  1. The most abundant element on the earth is;
  1. Carbon     B. Iron    C. Nitrogen    D. Oxygen
  1. Petrol is an example of;
  1. Ionic substance   C. Flammable substance 
  2. Irritating substance  D. Corrosive substance 
  1. Domestic utensils made of iron undergo rusting when exposed to;

A.  Air and fire   B. Air and oil   C. Air and water   D. Water and oil 

  1. The chloride iron (Cl-) differs from chlorine atom because chloride ion has;

A.  Loss electrons    B. Less protons   C. More electrons   D. More protons 

              x.   Which of the following chemical species have the same number of electrons? 

                    A. Cl, Be, He and O2-       B. K+, Ca2+, Cl- and Ar  

                    C. Na+, Mg2+, Al3+ and Li   D. O2-, F-, S2- and Cl- 

2. (a) You are provided with two lists A and B. Choose a words from list B which matches the statement or phrase in List A and write its letter in the table provided below; 

LIST A

LIST B

  1. Covalent bond
  2. Increases from left to right across the period in the periodic table.
  3. Environmental friendly fuel.
  4. Method used to extract oil from nuts.
  5. Addition of hydrogen to a substance or removal of oxygen from a substance.
  1. Biogas
  2. Electronegativity
  3. Solvent extraction
  4. Reduction
  5. Electron sharing
  6. Electrostatic forces
  7. Corrosive
  8. Irritating
  9. Water and Kerosene
  10. Isotopy
  11. Data analysis
  12. Solution extraction
  13. Mortar and pestle
  14. Desiccator
  15. Painting
  16. Catalyst

SECTION B: 80 MARKS

  1. (a) What do you understand by the following terms?
  1. First Aid ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
  2. First Aid Kit ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(b) Name four components which can be found in First Aid Kit; 

  1. …………………………………………………………………………………………………………
  2. …………………………………………………………………………………………………………
  3. …………………………………………………………………………………………………………
  4. …………………………………………………………………………………………………………

(c) Why is it important to provide First Aid to an injured person? Give four reasons;

  1. …………………………………………………………………………………………………………
  2. …………………………………………………………………………………………………………
  3. …………………………………………………………………………………………………………
  4. …………………………………………………………………………………………………………
  1. (a) For each of the following classes of fire, state the burning material(s);
  1. Class A fire ……………………………………………………………………………………………
  2. Class B fire ……………………………………………………………………………………………
  3. Class C fire ……………………………………………………………………………………………

(b) Fire can be prevented by; 

  1. …………………………………………………………………………………………………………
  2. …………………………………………………………………………………………………………
  3. …………………………………………………………………………………………………………
  4. …………………………………………………………………………………………………………
  1. (a) By giving one example, define the following terms;
  1. Suspension ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
  2. Chromatography ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(b) Briefly explain the following ways of preventing rusting. 

  1. Electroplating ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
  2. Galvanizing ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(c) Write the chemical symbols for the following elements; 

  1. Silver ………………………..
  2. Iron ………………………….
  3. Aluminium …………………….
  1. (a) If a mixture of manganese (IV) oxide, MnOwith potassium chlorate, KClO3 is treated, which of

     the two compounds will produce oxygen? 

  1. …………………………………………………………………………………………………
  2. Why? ………………………………………………………………………………………….

(b) Calculate the oxidation number of the underlined elements;

  1. NH4+
  2. SO42-
  3. CUSO4
  4. FeCl2
  1. (a) List down four assumptions of the Dalton’s Atomic Theory;
  1. ……………………………………………………………………………………………………
  2. …………………………………………………………………………………………………
  3. …………………………………………………………………………………………………
  4. …………………………………………………………………………………………………

(b) Write a chemical formula for each of the following compounds;

  1. Water …………………………………………………………..
  2. Potassium chloride ………………………………………………
  3. Magnesium oxide ………………………………………………….
  4. Calcium hydroxide ……………………………………………….

(c) (i) What do you understand by the term “Chemical warning signs”? ……………………………………………………………………………………………………………

  (ii) Draw the chemical warning sign that represents; 

HARMFUL OR IRRITANT 

TOXIC 

FLAMMABLE 

  1. Study the periodic table below;

 I                                                                                        VIII

                                    II         III         IV         V         VI        VII

C

A

D

E

F

G

H

J

Use the letters shown in the periodic table above to indicate; 

  1. Elements with zero valency …………………………
  2. The lightest atom. …………………………………….
  3. The alkaline earth match. ……………………………………
  4. An element with electronic configuration of 2: 8: 1. …………………………..
  5. Give the names of elements represented by the mentioned letters A, B, C and D. ……………………………………………………………………………………
  6. Give the name of J as an element. ………………………………………………….
  7. Write the electronic configuration of J. …………………………………………….
  8. What type of a bond can be formed when element J combined with element H? ……………………………………………………………………
  9. What type of a bond can be formed when an element H combines with an element H …………………………………………………………………
  1. (a) What is air? ………………………………………………………………………………………………………………………………………………………………………………………………………………………….

(b) Mention the composition of air with their percentage composition; 

COMPOSITION 

PERCENTAGE (%) COMPOSITION 

  1. ……………………………………..
  2. ……………………………………..
  3. ……………………………………..
  4. ……………………………………...

……………………………………..

……………………………………..

……………………………………..

           ……………………………………...

(c) Give four reasons why air is a mixture. 

  1.  ……………………………………………………………………………………………………
  2. …………………………………………………………………………………………………
  3. …………………………………………………………………………………………………

                 iv       …………………………………………………………………………………………………

  1. (a) Give the method used to separate the following mixtures;
  1. Kerosene and water …………………………………………………………………………………
  2. Alcohol (ethanol) and water ………………………………………………………………………..
  3. Iron fillings and sand ……………………………………………………………………………….
  4. Iodine crystals and table salt ……………………………………………………………………….

(b) Water is a chemical compound? Give four reasons to support this fact. 

  1. ………………………………………………………………………………………………………
  2. ……………………………………………………………………………………………………….
  3. ……………………………………………………………………………………………………….
  4. ………………………………………………………………………………………………………

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 57

Candidate’s Examination Number ________________________

THE PRESIDENT’S OFFICE MINISTRY OF EDUCATION, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

CHEMISTRY MID TERM EXAMINATION-MARCH

FORM TWO-2021

Time: 2:30Hours

Instructions.

  1. This paper consists of section A, and B with a total of 10 questions
  2. Answer all questions in spaces provided.
  3. Section A carries 20 marks, section B 80 marks.
  4. All answers should be written in the spaces provided.
  5. All communication devices, calculators and any unauthorized material are not allowed in examination room.
  6. Write your number on every page of your answer booklet.
  7. The following atomic masses may be used: H=1, N=14, O=16, S=32

SECTION A (20 Marks)

Answer All questions in this section.

1. For each of the items (i)-(x), choose the correct answer from the alternatives given.

  1. Isotopes are atoms of the same element that have different
  1. Atomic number
  2. Electronic arrangement
  3. Mass number
  4. Protons
  1. The process by which water is converted into water vapour or steam is called
  1. Condensation
  2. Evaporation 
  3. Precipitation 
  4. Transpiration
  1. In the Bunsen burner a sooty flame is most likely to be formed when the
  1. Air holes are fully closed 
  2. Air holes are opened
  3. Flame is noisy 
  4. Flame is smaller
  1. The best method to separate a mixture of iodine and iron is
  1. Decantation
  2. Evaporation to dryness
  3. Fractional to dryness 
  4. Sublimation
  1. In scientific study, the tentative explanation of the observed chemical phenomenon can be proved by
  1. Data analysis 
  2. Experimentation
  3. Hypothesis 
  4. Observation
  1. The choice of the source of heat depends on the_____
  1. Colour of the flame 
  2. Quantity of heat produced
  3. Substance to be burned or boiled
  4. Type and shape of the flame
  1. When oxygen combines with metal they:-
  1. Form metallic oxides
  2. Form precipitation
  3. Form rust 
  4. Sublime
  1. When dilute hydrochloric acid react with metal the product is______
  1. Hydrogen chloride gas
  2. Hydrogen gas
  3. Chloride gas 
  4. Hydrogen peroxide
  1. Hydrogen react with sulphur to yield_______
  1. Hydrogen sulphide 
  2. hydrogen sulphate
  3. Sulphur dioxide
  4. Sulphur trioxide
  1. The product smell obtained from the combustion of sulphur in air is_____
  1. Pleasant 
  2. Toxic 
  3. pungent
  4. Harmful

i

ii

Iii

iv

v

Vi

vii

viii

ix

x











2. (a) You are provided with two list A and list B choose a statement which match the word in list A and write appropriate word in the space provided

LIST A

LIST B

  1. In weather balloons
  2. Preparation of water gas
  3. Manufacture of margarine
  4. Production of oxy-hydrogen flame
  5. Fire triangle
  1. Fires resulting from fats and oil
  2. Used to refer to components needed to start fire
  3. It readily combines with other elements
  4. It is odourless
  5. It is highly flammable
  6. It is lighter than air
  7. It is a reducing agent
  8. It burns with a blue flame
  9. Materials that produce heat on burning


I

Ii

Iii

Iv

v






(b) Fill the blanks for each of the following

  1. _____________________is the smallest particle of an element that has all the chemical properties of that element.
  2. _______________________is a negative charged particle with a mass of approximately equal to .
  3. _________________________is the process of making water clean and safe for human consumption
  4. __________________________is the process where y aluminium sulphate and impurities in water clump together and sink to the bottom of container
  5. Water treatment is ________________________________________________________________________________________________________________________________________________

SECTION B (80 Marks)

3. (a) Use a diagram to explain the preparation of hydrogen using dilute hydrochloric acid and zinc granules

(b) Briefly explain four uses of hydrogen

(i)______________________________________________________________________________________________________________________________________________ (ii)_____________________________________________________________________________________________________________________________________________ (iii)_____________________________________________________________________________________________________________________________________________ (iv)_____________________________________________________________________________________________________________________________________________

4. (a) List four Dalton’s atomic theories

  1. ____________________________________________________________________________________________________________________________________
  2. ____________________________________________________________________________________________________________________________________
  3. ____________________________________________________________________________________________________________________________________
  4. ____________________________________________________________________________________________________________________________________

(b) State four modifications of Dalton’s atomic theories

  1. ____________________________________________________________________________________________________________________________________
  2. ____________________________________________________________________________________________________________________________________
  3. ____________________________________________________________________________________________________________________________________
  4. ____________________________________________________________________________________________________________________________________

(c) Mention two shortcomings of Dalton’s atomic theory

  1. ____________________________________________________________________________________________________________________________________
  2. ____________________________________________________________________________________________________________________________________

5. (a) Write down six physical properties of water

  1. __________________________________________________________________
  2. __________________________________________________________________
  3. __________________________________________________________________
  4. __________________________________________________________________
  5. __________________________________________________________________
  6. __________________________________________________________________
  1. Give four reasons why water is important in our daily lives and industry.
  1. ______________________________________________________________________________________________________________________________
  2. ______________________________________________________________________________________________________________________________
  3. ______________________________________________________________________________________________________________________________
  4. ______________________________________________________________________________________________________________________________

6. (a) Give the meaning of each of the following sub atomic particles

  1. Proton

____________________________________________________________________________________________________________________________________

  1. Electron

____________________________________________________________________________________________________________________________________

  1. Neutron

____________________________________________________________________________________________________________________________________

(b) Differentiate between physical and chemical change of matter (five differences)

Physical change

Chemical change

i.


ii.


iii.


iv.


v.


(c) (i) Write the equation for the preparation of oxygen by heating potassium chlorate

(ii) How oxygen is tested in the laboratory

________________________________________________________________________________________________________________________________________________

7. (a) With chemical equation, give the product of combustion in oxygen of

  1. A non metal ____________________________________________________________________________________________________________________________________
  2. A metal , each of your own choice ____________________________________________________________________________________________________________________________________

(b) (i) Define catalyst ________________________________________________________________________________________________________________________________________________

(ii) In experiment of preparation of hydrogen, why copper (II) sulphate is added into the solution of zinc granules and dilute sulphuric acid? ________________________________________________________________________________________________________________________________________________

  1. Why were the first few bubbles of gas not collected? ____________________________________________________________________________________________________________________________________
  2. Write the word equation for the reaction during preparation of hydrogen gas by zinc granules __________________________________________________________________
  3. Suggest two ways how hydrogen is collected during its preparation ____________________________________________________________________________________________________________________________________
  4. Suggest one problem with collecting hydrogen by upward delivery, remember hydrogen is colourless ____________________________________________________________________________________________________________________________________

8. (a) Explain four methods of preventing rusting of iron (i)______________________________________________________________________ (ii)_____________________________________________________________________ (iii)_____________________________________________________________________ (iv)_____________________________________________________________________

(b) In the following diagram of interconverting of matter name the processes from a to f

  1. _________________________________
  2. _________________________________
  3. _________________________________
  4. _________________________________
  5. _________________________________
  6. _________________________________

9. (a) Study the diagram below and answer the questions that follow

  1. What process is taking place? ____________________________________________________________________
  2. Name the parts labeled A to D
  1. ______________________________________
  2. ______________________________________
  3. ______________________________________
  4. ______________________________________

(b) For each of the following classes of fire state the burning material and give its suitable fire extinguisher

Class 

Burning material

Fire extinguisher

Class A



Class B



Class C



Class D



Class E



10. (a) Draw the following warning signs as used in the laboratory, for each give two examples

Name

Diagram

Examples 

Toxic



Flammable



Oxidant



Radioactive



(b) Define each of the following terms

  1. Warning signs ____________________________________________________________________________________________________________________________________
  2. Laboratory ____________________________________________________________________________________________________________________________________

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 47

THE PRESIDENTS OFFICE MINISTRY OF LOCAL GOVERNMENT AND REGIONAL ADMINISTRATION

FORM II CHEMISTRY MIDTERM MARCH-2021

1. For each of the items (i)-(x) choose the correct answer from among the given alternatives and write its letter in the box provided.

  1. Which of the following does not constitute a fire triangle?
  1. Oxygen
  2. Fuel
  3. Combustible material
  4. Heat.
  1. Why is oxygen regarded as one of the most important part of air?
  1. It supports combustion
  2. It is a diatomic gas
  3. It forms the largest part of air
  4. It has the largest density.
  1. Which is not a property of oxygen gas?
  1. Colorless
  2. Odorless
  3. Burns
  4. Denser than air.
  1. A simple proof that chemical reaction takes place in our bodies is that;
  1. We occasionally fall sick
  2. Doctors tell us in hospitals
  3. The food or drink we take is different from the waste product produced
  4. We cook food
  1. A chemist will require the following skills except?
  1. Experimentation
  2. Observation
  3. Problem identification
  4. Surgery
  1. Burning back in Bunsen burner occur when
  1. Air hole is closed
  2. Bunsen burner is overheated
  3. Gas supply is high
  4. Air hole is fully open
  1. The most common source of heat in laboratory is
  1. Kerosine stove
  2. Liquefied petroleum
  3. Spirit lamb
  4. Bunsen burner
  1. A gas was passed into test tube containing lime water. The lime water turned milky. The gas was mostly likely to be;
  1. Sulphur dioxide
  2. Carbon monoxide
  3. Carbon dioxide
  4. Nitrogen dioxide.
  1. In which class of fire will you put kerosine?
  1. Class A
  2. Class B
  3. Class C
  4. Class E
  1. What do you call an instrument used to hold and heat chemicals?
  1. Measuring cylinder
  2. Gas jar
  3. Test tube
  4. Funnel

2. Match the correct answer in list A with alternative given in list B by writing the answer of the correct answer in the spaces provided.

LIST A

LIST B

  1. Lowest temperature at which combustible material takes fire and continue to burn,
  2. Burning substances in presence of oxygen
  3. Used to fill electric bulbs
  4. Some of the products of burning candle
  5. Fire caused by flammable gases
  1. Rusting
  2. Combustion
  3. Kindling point
  4. Burning point
  5. Argon
  6. Helium
  7. Carbon dioxide and water
  8. Hydrogen and carbon
  9. Class c fire
  10. Class D fire

3. Complete the following statements with the correct answers

  1. A substance that can burn is said to be . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
  2. A gas that occupies the largest part of atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
  3. Another name for anodizing as method of preventing rusting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
  4. Chemical name of rust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
  5. Liquid obtained after distillation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 
  1. (a) Write six methods that can be used to prevent rusting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

(b) Mention the conditions required for rusting

5. (a) Which property of hydrogen make it to be used in the following ways

  1. Oxyhydrogen flame
  2. Weather balloon
  3. Manufacture of margarine

(b) Which property of oxygen makes to be used as follows

  1. Respiration
  2. Cutting metals and welding
  3. Removal of impurities
  1. (a) Define the following terms
  1. Laboratory
  2. First aid
  3. First aid kit
  4. Matter

(b) Mention five laboratory rules

7. (a) Name the chemicals mostly used in laboratory to prepare oxygen.

(b) State the way you can test for presence of oxygen

(c) Explain four chemical properties of oxygen.

8. (a) By giving an example in each case, define the following terms

  1. A chemical symbol
  2. An element
  3. A compound
  4. A suspension

(b) Write the names of the elements presented by the following symbols

  1. Au
  2. Ag
  3. Hg
  4. P
  5. Sn

9. (a) Mention five accidents that can happen in laboratory?

(b) State five ways we can do to minimize accidents in laboratory

10. (a) What is a flame?

(b) Mention two types of flames

(c) Explain why Bunsen burner is the best flame to use in laboratory

(d) Give differences between luminous and non-luminous flame

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 38

THE PRESIDENT'S OFFICE

MINISTRY OF REGIONAL GOVERNMENT AND LOCAL GOVERNMENT

AUGUST-SEPTEMBER   EXAMINATION SERIES

CHEMISTRY FORM-2

2020

TIME: 2:30 HRS

INSTRUCTIONS. 

  1. This paper consists of sections A and B with a total of ten (10) questions.
  2. Answer all questions in spaces provided.
  3. All writing must be in blue or black ink except drawing which must be in pencil.
  4. Calculators, cellular phones and any unauthorized materials are not allowed in the examination room.
  5. Write your Examination Number at the top right corner of every page.
  6. The following atomic masses may be used; H =1, N =14, O = 16, S = 32, Ca = 40

 

SECTION A (20 Marks)

Answer all questions in this section.

1. For each of the items (i) –(x), choose the correct answer from the among the given alternatives and write its letter in the box provide.

(i) Chemistry is defined as:

  1. The scientific study of matter, compounds and chemical reactions
  2. The scientific study of compounds, mixtures and organic substances
  3. The scientific study of composition, structure and properties of matter
  4. The study of relation between human being, medicine and pollution.

(ii) A non-luminous flame is the most applicable flame for heating purposes because:

  1. It is very noisy
  2. It has no soot
  3. It is very hot
  4. It has no colour

(iii) Matter is defined as anything that has:

  1. Volume and occupies space
  2. Mass and occupies space
  3. Mass and occupies density 
  4. Density and space

 (iv) Which of the following process is used in preventing rust of an iron?

  1. Water
  2. Boiling
  3. Salting
  4. Galvanization

 (v) Water is a universal solvent because:

  1. It is available everywhere
  2. It boils at 1000C
  3. It dissolves most of the solutes
  4. It dissolves all crystals in compounds

(vi) Which among the following are the two processes involved during distillation?

  1. Evaporation and sublimation 
  2. Evaporation and crystallization
  3. Evaporation and condensation 
  4. Evaporation and decantation

 (vii) Which of the following set of nuclide notation represents isotopes? 

  1. 18 X 16 X 19
  2. 18 X 18 X X 
  3.  16 x 18 x 1890x 
  4.  16 X 1789x,

 (viii) The chemical used to test the presence of water in a substance is:

     A. Cobalt Il oxide                        B. Cobalt 111 oxide

    C.  Cobalt chloride     D.   Copper Il chloride

image (ix) When a burning fuel produces blue colour it means there is:

   A. adequate supply of oxygen with production of soot

   B. inadequate supply of oxygen with production of more heat.

image  C. inadequate supply of oxygen with production of soot.

   D. adequate supply of oxygen with production of more heat.

image(x) Which of the following is the best apparatus for measuring accurately a fixed volume of a given solution?

 A. Measuring cylinder          B. Beaker

   C. Pipette                            D. Burette

 

2. Match each item in List A with a correct response in List B by writing its letter bellow the number of the corresponding item in the table provided.

LIST A

LIST B

  1. Group of elements which react quickly with water to form alkaline solution.
  2. The ability of an atom to attract an electron.
  3. Group of elements in which their shells are completely filled up.
  4. A vertical column of elements in the periodic table.
  5. Group element which react slowly with water to form alkaline solution.

A. Metalloids

B. Non-metals

C. Periodicity

D. T r a n s i t i o n

elements

E. Electro negativity

F. Alkali metals

G. Halogens

H. Periodic law

I. Alkali earth metals

J. Rare non metals

K. Period

L. Noble gases

M. Periodic table

N. Group

 

 

          SECTION B. 80 MARKS

3.(a) Define the following terms:

(i)Oxidation state image

(ii)An element .......„

(iii)A compound

(iv)Fainting 

(b)Write the chemical formula for each of the following compounds:

(i)Sodium sulphate image

(ii)Sodium chloride .. image

(iii)Calcium nitrate ......... (iv) Calcium oxide .

4.Gas X can be prepared in the laboratory by the decomposition of hydrogen peroxide.

(a)Identify gas X .. image

(b)State three physical properties of Gas X

imageMention three chemical properties of gas X. (d) State three uses of gas X.

5.Write the name of each of the following compounds:

(i)(NH4)2C03

(ii)CaCl2

(iii) NaSO4

(iv) KC103

(b)Give three differences between the following:

(i)   imageElectrovalent compounds and covalent compounds. (ii) Solutions and suspensions.

6.(a) Define the following terms:

(i)Covalent bond

(ii)Electrovalent bond

(b)      A compound consists of 82.8% carbon and 17.2% hydrogen by mass. The vapour density of the compound is 29. Calculate:

(i)Empirical formula.

(ii)Molecular formula.

7.(a) Define the following terms as applied in Chemistry:

(i)Flame image

(ii)Bunsen burner

(iii)Laboratory

(b)      List four properties of each of the following:

(i)       A luminous flame

(ii)     A non-luminous flame

8.(a) Write a word equation for each of the following reactions:

(i)Calcium burns in Oxygen .........

(ii)Sodium reacts with water ... ... ...

(b)      What do you understand by the following terms?

(i)       Water treatment

(ii)     Water purification

(c)       Mention six uses of water in economic activities.

9.(a) Mention four physical properties of water.

(b)      What will happen when:

(i)       a burning splint of wood is introduced into a gas jar containing oxygen gas 

(ii)     oxygen gas reacts with metals . 

(iii)   hydrogen gas reacts with oxygen gas .........

(c)      List four uses of hydrogen in our daily life.

10.           What do you understand by the term "valency"?

(b) Calculate the oxidation number of the underlined elements: (i) NaOH

(i) CO3

(iii) Na3P04

(iv) NO2

(v) S02

(c) State the importance of changes of state in daily life.

 

 

 

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 31

THE PRESIDENT’S OFFICE MINISTRY OF EDUCATION, LOCAL ADMINISTRATION AND LOCAL GOVERNMENT

CHEMISTRY- BACK TO SCHOOL EXAMINATION-JUNE

FORM TWO

Time 2:30 Hours JUNE 2020

INSTRUCTIONS.

  1. This paper consists of sections A and B with a total of ten (10) questions.
  2. Answer all questions in spaces provided.
  3. All writing must be in blue or black ink except drawing which must be in pencil.
  4. Calculators, cellular phones and any unauthorized materials are not allowed in the examination room.
  5. Write your Examination Number at the top right corner of every page.
  6. The following atomic masses may be used; H =1, N =14, O = 16, S = 32, Ca = 40

SECTION A (20 Marks)

Answer all questions in this section.

1. For each of the items (i) –(x), choose the correct answer from the among the given alternatives and write its letter in the box provide.

(i) What is the best way of keeping a clean test tube after use?

  1. Keeping it in water
  2. Keeping it on a test tube holder
  3. Keeping it in a basin for test tubes
  4. Keeping it on a test tube rack.

(ii) What happens when substance A reacts with substance B to form a new substance C?

  1. Substance A and B are said to have formed a solution
  2. Substance A and B are said to have undergone a physical change.
  3. Substance A and B are said to have undergone a chemical change.
  4. Substance A and B are said to have undergone a dissolution.

(iii) Why Non – luminous flame is the most applicable flame for heating purposes?

  1. It is very nosy
  2. It has no soot.
  3. It is very hot
  4. It has air holes open

(iv) How many zones are there in a non-luminous flame?

  1. Four zones
  2. Two zones
  3. Three zones
  4. Five zones

(v) When a small amount of sugar is dissolved in a glass of water the mixture formed is:

  1. heterogeneous.
  2. immiscible.
  3. suspension.
  4. homogenous.

(vi) A change from gaseous state to solid state without passing through a liquid state is called:

  1. Deposition
  2. Sublimation
  3. Condensation
  4. Solidification

(vii) Which among the following are the two processes involved during distillation?

  1. Evaporation and sublimation
  2. Evaporation and crystallization
  3. Evaporation and condensation
  4. Evaporation and decantation

(viii) Technicians prefer to use blue flame in welding because:

  1. It is bright and non-sooty
  2. It is light and non-sooty
  3. It is very hot and large
  4. It is very hot and non-sooty

(ix) Which of the following is a sequential method of separating mixture of salt and sand?

  1. Evaporation, filtration and decantation
  2. Decantation, evaporation and filtration
  3. Sedimentation, evaporation and filtration
  4. Decantation, filtration and evaporation

(x) The factors that affect the problem being investigated are referred to as:

  1. Dependent factors
  2. Variables
  3. Independent factors
  4. Conditions

2. Match each item in List A with a correct response in List B by writing its letter bellow the number of the corresponding item in the table provided.

LIST A

LIST B

(i) Method of recovery of both solute and solvent from a liquid.

(ii) Method of separating two miscible liquids which their boiling points are close together.

(iii) Method of separating two immiscible liquids.

(iv) Method of separating two solids by heating in a way that one changes its state directly to gas.

(v) Method of separating coloured components using a moving solvent on materials that absorb such solvent.

  1. Simple distillation
  2. Evaporation
  3. Fractional Distillation
  4. Separating funnel
  5. Decantation
  6. Chromatography
  7. Sublimation
  8. Solvent extraction.

(b) Fill in the blank spaces by using the appropriate terms.

  1. Smallest particles that makes up matter ……………………………….
  2. The substance obtained after filtration is called……………………..
  3. The factors that make distillation possible is difference in………….
  4. Directly change from solid to gas………………………………….
  5. The temperature at which a liquid changes into gas…………………

SECTION B (80 Marks)

Answer all questions in this section.

3. (a) State one use of each of the items (i) – (x) in administering First Aid.

S/N

Item

Use

(i)

Soap

(ii)

Bandage

(iii)

Sterile gauze

(iv)

Iodine tincture

(v)

Petroleum jelly

b. (i) Write the name and chemical formula of two important chemical substances used in the laboratory preparation of oxygen gas.

(ii) Mention four physical properties of oxygen gas.

4. (a) What are the five steps used in lighting a Bunsen burner?

(b) Classify fuels based on their physical state and for each class give two examples.

5.(a) Study the experiment diagram below and answer the questions that follow.

(i)What happens to the copper (Il) oxide during the experiment?

(ii)What happens to the two pieces of cobalt paper? (iii) Write a word equation for the reaction.

(b) Mention four chemical properties of hydrogen gas.

6.(a) Define the following terms as applied in Chemistry:

(i)Flame

(ii)Bunsen burner

(iii)Laboratory

(b) List four properties of each of the following:

(i) A luminous flame

(ii) A non-luminous flame

7.(a) Define the following terms:

(i)Chemistry

(ii)Element

(iii)Catalyst

(b) Give three differences between the following:

(i) Compound and mixture

(ii) Suspension and solution

8. (a) Write a word equation for each of the following reactions:

(i)Calcium burns in Oxygen .........

(ii)Sodium reacts with water ... ... ...

(b) What do you understand by the following terms?

(i) Water treatment

(ii) Water purification

(c) Mention six uses of water in economic activities.

9. State the law of conservation of energy.

(b) Give two ways in which energy can be transformed from one form to another.

(c) List down two sources of heat in the laboratory.

10.(a) Define the term "empirical formula".

(b) An organic compound contains 26.7% carbon, 2.2% hydrogen and

71.1% oxygen. If its relative molecular mass is 90, determine its:

(i)Empirical formula

(ii)Molecular formula

(c ) State the modern atomic theory ideas.

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 24

THE PRESIDENT’S OFFICE MINISTRY OF EDUCATION, LOCAL ADMINISTRATION AND LOCAL GOVERNMENT

CHEMISTRY- TERMINAL EXAMINATION-MAY

FORM TWO

TIME: 2HRS                                                                   2020

NAME:_____________________________________CLASS:___________

 INSTRUCTIONS 

  • Do all questions from sections A, B and C. 
  • All working must be shown clearly and neatness
  • The following atomic masses may be used;

H = 1, C = 12, O = 16, N = 14, Ca = 40, K = 39. 

  • All writing must be done in black or blue ink EXCEPT for the diagrams which must be in pencil. 

SECTION A: 10 MARKS

1. Write down the letter corresponding to the correct answer for each item (i) – (x).

(i) The valency of an element with atomic number 10 is;

  1. 2
  2.  3
  3. 0

(ii) How many protons, neutrons and electrons are there in an atom represented by the symbol

Protons   Neutrons  Electrons 

  1. 39  19  20
  2. 19  39  20
  3. 20  19  20
  4. 19  20  19

(iii) Separation of a mixture by fraction all distillation is possible if the mixture constituents differ in their;

  1. Boiling points
  2. Melting points
  3. Freezing points
  4. Vapourizing points

(iv) When element T of Group 1 combines with element X of Group VI, the formula of the compound formed is;

  1. T2
  2.  X2T
  3. TX2 
  4. XT

(v) Saturated solution is one which;

  1. Contains more solute undissolved  at a given temperature
  2. Has a large amount of solvent at a given temperature
  3. Contains a little solute at a given temperature
  4. Will take no more of solute at a given temperature

(vi) The most abundant element on the earth is;

  1. Carbon
  2. Iron
  3. Nitrogen
  4. Oxygen

(vii) Petrol is an example of;

  1. Ionic substance 
  2.  Irritating substance  
  3.  Flammable substance
  4. Corrosive substance

(viii) Domestic utensils made of iron undergo rusting when exposed to;

  1. Air and fire
  2. Air and oil
  3. Air and water
  4. Water and oil 

(ix) The chloride iron (Cl-) differs from chlorine atom because chloride ion has;

  1. Loss electrons 
  2. Less protons
  3. More electrons
  4. More protons 

(x) Which of the following chemical species have the same number of electrons? 

  1. Cl, Be, He and O2-
  2. K+, Ca2+, Cl- and Ar  
  3. Na+, Mg2+, Al3+ and Li 
  4.  O2-, F-, S2- and Cl-  

SECTION B: 20 MARKS

2. You are provided with two lists A and B. Choose a words from list B which matches the statement or phrase in List A and write its letter in the table provided below;

LIST A

LIST B

  1. Covalent bond
  2. Increases from left to right across the period in the periodic table.
  3. Environmental friendly fuel.
  4. Method used to extract oil from nuts.
  5. Addition of hydrogen to a substance or removal of oxygen from a substance.
  6. The forces holding the oppositely charged ions.
  7. Substance which can burn your skin.
  8. Immiscible liquids
  9. Modern scientific procedures
  10. Used for grinding solid chemicals
  1. Biogas
  2. Electronegativity
  3. Solvent extraction
  4. Reduction
  5. Electron sharing
  6. Electrostatic forces
  7. Corrosive
  8. Irritating
  9. Water and Kerosene
  10. Isotopy
  11. Data analysis
  12. Solution extraction
  13. Mortar and pestle
  14. Desiccator
  15. Painting
  16. Catalyst

SECTION C: 70 MARKS

  1. (a) What do you understand by the following terms?
  1. First Aid …
  2. First Aid Kit

(b) Name four components which can be found in First Aid Kit; 

(c) Why is it important to provide First Aid to an injured person? Give four reasons;

4. (a) For each of the following classes of fire, state the burning material(s);

  1. Class A fire 
  2. Class B fire 
  3. Class C fire 

(b) Fire can be prevented by; 

5. (a) By giving one example, define the following terms;

  1. Suspension 
  2. Chromatography 

(b) Briefly explain the following ways of preventing rusting. 

  1. Electroplating 
  2. Galvanizing 

(c) Write the chemical symbols for the following elements; 

  1. Silver ………………………..
  2. Iron ………………………….
  3. Aluminium …………………….

6. (a) If a mixture of manganese (IV) oxide, MnOwith potassium chlorate, KClO3 is treated, which of the two compounds will produce oxygen? 

  1. …………………………………… 
  2. Why? ……………………………………

(b) Calculate the oxidation number of the underlined elements;

  1. NH4+
  2. SO42-
  3. CUSO4
  4. FeCl2

7. (a) List down four assumptions of the Dalton’s Atomic Theory;

(b) Write a chemical formula for each of the following compounds;

  1. Water ……………………
  2. Potassium chloride ……… …
  3. Magnesium oxide ………… 
  4. Calcium hydroxide ………… .

(c) (i) What do you understand by the term “Chemical warning signs”?

  (ii) Draw the chemical warning sign that represents; 

HARMFUL OR IRRITANT 

TOXIC 

FLAMMABLE 

 

 

 

 

 

 

8. Study the periodic table below;

 

Use the letters shown in the periodic table above to indicate; 

  1. Elements with zero valency ………………
  2. The lightest atom. ……………………… .
  3. The alkaline earth match. ……………… 
  4. An element with electronic configuration of 2: 8: 1. …………………………..
  5. Give the names of elements represented by the mentioned letters A, B, C and D. …………………
  6. Give the name of J as an element. ……………………… 
  7. Write the electronic configuration of J. …………………… ……………….
  8. What type of a bond can be formed when element J combined with element H? ………………………… …
  9. What type of a bond can be formed when an element H combines with an element H ……………………… 

9. (a) What is air? 

(b) Mention the composition of air with their percentage composition; 

COMPOSITION 

PERCENTAGE (%) COMPOSITION 

  1. ……………………………………..
  2. ……………………………………..
  3. ……………………………………..
  4. ……………………………………...
  1. …………………… 
  2.  ………………….
  3. …………………..
  4. …………………...

 (c) Give four reasons why air is a mixture. 

10. (a) Give the method used to separate the following mixtures;

  1. Kerosene and water ………………… 
  2. Alcohol (ethanol) and water …………………
  3. Iron fillings and sand …………………………
  4. Iodine crystals and table salt …………… …….

(b) What is a chemical compound? Give four reasons to support this fact.

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 15

THE PRESIDENT’S OFFICE

THE MINISTRY OF EDUCATION AND VOCATIONAL TRAINING

MID TERM EXAMINATIONS-MARCH 2020

032                                                                   CHEMISTRY

 

Duration: 2:30 Hours

 

INSTRUCTIONS.

 

  1. This paper consists of sections A and B with a total of ten (10) questions.
  2. Answer all questions in spaces provided.
  3. All writing must be in blue or black ink except drawing which must be in pencil.
  4. Calculators, cellular phones and any unauthorized materials are not allowed in the examination room.
  5. Write your Examination Number at the top right corner of every page.
  6. The following atomic masses may be used; H =1, N =14, O = 16, S = 32, Ca = 40

 

SECTION A (20 Marks)

Answer all questions in this section.

 

1. For each of the items (i) –(x), choose the correct answer from the among the given alternatives and write its letter in the box provide.

 

            (i) All domestic utensils made of iron undergo rusting when exposed to:

  1. Air and fire
  2. Air and oil
  3. Air and water
  4. Water and oil

(ii) When a small amount of common salt is dissolved in glass of water the mixture formed is:

  1. Heterogeneous
  2. Homogeneous
  3. Immiscible
  4. Suspension

(iii) A chemist should acquire all of the following skills except:

  1. Experimentation
  2. Observation
  3. Problem identification
  4. Surgery

(iv) An important property of oxygen which distinguishes it from other gases is that it:

  1. Burns and supports combustion
  2. Burns but does not support combustion
  3. Neither burns nor supports combustion
  4. Supports combustion but does not burn.

(v) The process of chlorination in water treatment aims at:

  1. Forming suspension
  2. Killing micro – organisms
  3. Making syrup
  4. Removing bad odour

(vi) Class E fire can best be extinguished by using:

  1. Carbon dioxide
  2. Fire blanket
  3. Sand
  4. Water

(vii) The following is a set of apparatuses which are used for heating:

  1. Crucible, test tube, evaporating dish
  2. Evaporating dish, tongs, crucible
  3. Test tube, evaporating dish, tongs
  4. Tongs, crucible, test tube.

(viii) Which of the following methods can be used to get oil from cotton seeds?

  1. Decantation
  2. Distillation 
  3. Grinding and distillation
  4. Grinding followed by squeezing.

(ix) The substance that can be used to extinguish fire are:

  1. Carbon dioxide and sand
  2. Carbon dioxide and sugar
  3. Nitrogen and sand
  4. Nitrogen and water

 

 

(x) When sugar is dissolved in water, a uniform mixture is formed. The resulting mixture is called a:

  1. Solute
  2. Solution
  3. Solvent
  4. Suspension

 

2.(a)  Match each item in List A with a response in List B by writing its letter below the number of the corresponding item in the table provided.

 

List A

List B

  1. A method used to separate mixture of two or more liquids that form homogeneous solution by means of fractional column.
  2. A substance that absorbs moisture from the atmosphere and dissolves in it.
  3. Poisonous gases prepared in it.
  4. Produces a “pop” sound
  5. Used to prevent direct heat to reach the apparatus

 

  1. Evaporation
  2. Tripod stand
  3. Wire gauze
  4. Cupboard
  5. Fume chamber
  6. Hydrogen
  7. Oxygen
  8. Delinquency
  9. hygroscopic

 

   (b) Fill in the blank spaces by using the appropriate terms

  1. In an atom, the effect of the charged nucleons is balanced by the charge of……………..
  2. Serum is separated from blood samples by employing a technique called………………..
  3. Boiling points of substances reflect the strength of……………….
  4. Grinding chalk into a powder involves changing the state of …………………….
  5. The insoluble substances formed during filtration are collectively termed as ……………….

 

 

SECTION B (80 Marks)

Answer all questions in this section.

 

3. (a) Mariam was preparing food foe  her family using hot oil in a frying pan. Accidentally the pan  tripped over and a huge fire spread over her kitchen floor.

  1. Mention two extinguishers which would be appropriate for putting out the fire.
  2. Which fire extinguisher would be dangerous to use when trying to put out the fire in (a) above? Give reason.

    (b) Mention three conditions for a fire to start

    (c) (i) What is combustion?

          (ii) Give three areas where combustion is applied.

 

4. (a) In an experiment, two iron nails A and B were used whereby painting was applied on nail A. The two nails were placed in a moist environment and after one month the weight of each nail was determined. Which of the two nails would be heavier? Give reason.

    (b) State the method which will be used to protect each of the following from rusting:

  1. Covering iron sheets with a layer of most reactive metals
  2. Bicycle chain

 

5. (a) List down four careers that are a result of studying chemistry.

    (b) The following are possible causes of accidents which can occur in the Chemistry laboratory. State how you can avoid them.

  1. Poisonous chemicals left in an unlocked cupboard
  2. A student picking up a bottle containing concentrated H2SOacid by the neck
  3. Concentrated acids stored in the upper most shelf of cupboard.

6. (a) Mention four physical properties of water

    (b) What will happen when?

  1. A burning splint of wood is introduced into a gas jar containing oxygen gas
  2. Oxygen gas reacts with metals
  3. Hydrogen gas reacts with oxygen gas

    (c) List four uses of hydrogen in our daily life.

 

7. (a) Define the following terms as applied in Chemistry.

  1. Flame
  2. Bunsen burner
  3. Laboratory

    (b) List four properties of each of the following:

  1. A luminous flame
  2. A non – luminous flame

    (c) Give the use of each of the following components which are found in the First Aid Kit.

  1. Plaster
  2. A pair of scissors
  3. Cotton wool
  4. Gloves.

 

8. (a) Define the following terms;

  1. Chemistry
  2. Element
  3. Catalyst

    (b) Give three differences between the following:

  1. Compound and mixture
  2. Suspension and solution.

 

9. Gas “L” has the following properties: it is highly flammable, readily combines with other elements, readily reacts with other chemical substances and is a strong reducing agent.

  1. Name the gas “L”
  2. What is the method used to collect gas”L” in the laboratory? Give a reason.
  3. Give four uses of gas “L”

 

10. (a) Draw a diagram to show laboratory preparation of oxygen using hydrogen peroxide. In the diagram, label all the compounds and elements involved in the preparation.

       (b) Briefly explain how you would distinguish ordinary air from pure oxygen.

       (c) List two chemical properties of oxygen gas

LEARNINGHUBTZ.CO.TZFORM TWO CHEMISTRY EXAM SERIES 3

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