FORM TWO CHEMISTRY TERMINAL EXAMS

PRESIDENT OFFICE REGIONAL ADMNISTRATION

AND LOCAL GOVERNMENT

SECONDARY EXAMINATION SERIES 

COMPETENCE BASED ASSEMENT

CHEMISTRY FORM TWO

TERMINAL EXAMS-MAY– 2023 

033

Time: 2:30 Hours

INSTRUCTIONS

  1. This paper consists of sections A, B and C with a total of ten (10) questions.
  2. Answer all questions 
  3. Section A and C carry fifteen (15) marks each and Section B carry seventy (70) marks.
  4. All writing must be in blue or black ink except drawing which must be in pencil.
  5. Cellular phones and any unauthorized materials are not allowed in the assessment room.

SECTION A

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

(i) What is the best way of preparing hydrogen gas in the laboratory?

  1. By reacting strong metals and dilute acids.
  2. By reacting metals and acids.
  3. By reacting moderate metals and concentrated acids.
  4. By reacting moderate metals and dilute acids. 
  5. By reacting strong metals and strong acids.

(ii)Consider the following reagents:

  1. H2O2
  2. H2O
  3. MnO4
  4. .MnO2

Which reagents are involved in the preparation of oxygen gas in the laboratory?

  1. I and 2
  2. 3 and 4
  3. CI and 3
  4. 2 and 3
  5. I and 4

(iii)A good fuel is the one which has

  1. high speed of continuous energy supply.
  2. high energy value supplied.
  3. low carbon dioxide supplied.
  4. high carbon dioxide production.
  5. high content of non-combustible material.

(iv) Which of the following pairs constitute the best methods for treating and purifying water?

  1. Chlorination and aeration
  2. Chlorination and decantation
  3. Chlorination and filtration
  4. Chlorination and sedimentation
  5. Chlorination and distillation

(v)  A certain liquid dissolves copper (Il) sulphate to form a blue solution. This liquid is likely to be:

  1.  Hydrochloric acid
  2. Liquid oxygen
  3. Nitric acid
  4. Water
  5. Lime water


(vi)  Isotopes are atoms of the same element that have different:

  1. Atomic number
  2. Electron arrangement
  3. Mass number
  4. Protons
  5. Neutrons

(vii) 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
  5. Reacts with metals and Non-Metals

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

A. 2:8:1 and 2:5

B. 2:8:2 and 2:6

C. 2:8:3 and 2:8:8:7

D. 2:8:6 and 2:8:8:7

E. 2:8 and 2:8:7

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

  1. adequate supply of oxygen with production of soot
  2. inadequate supply of oxygen with production of more heat.
  3. inadequate supply of oxygen with production of soot. 
  4. adequate supply of oxygen with production of more heat.
  5. Insufficient fuel

(x) The process of coating iron or steel with zinc is known as:

  1. zinc painting.
  2. alloying.
  3. tin plating.
  4.  galvanization.
  5. Painting.

2. Match the description of a gas in list A with corresponding gas in List B and write the answer in the space provided.

LIST A

LIST B

  1. Has sweet taste smell and relights a glowing splint
  2. Reacts with lime water forming milky solution
  3. Most abundant gas in the atmosphere
  4. Flammable and used in balloons
  5. Supports most of chemical reactions
  1. Hydrogen
  2. Argon
  3. Nitrogen
  4. Carbon dioxide
  5. Oxygen
  6. Nitrogen I Oxide
  7. Helium
  8. Carbon monoxide

SECTION B. 70 MARKS- ANSWER ALL QUESTIONS IN THIS SECTION

3. (a) Define the following terms as used in chemistry.

  1. Atom                                                                                       
  2. Atomic number                                                                        
  3. Mass number                                                                                     
  4. Radicals                                                                                   
  5. Isotopes                                                                                   

(b) The table below shows the relative atomic masses and the percentage abundance of the   isotopes L1 and Lof element L

 

    Relative atomic mass 

       % abundance 

            L1 

          62.93 

        69.09 

            L2 

          64.93 

        30.91 

          Calculate the relative atomic mass of element L.    

4.(a)   The grid given below represents part of the periodic table. Study it and answer the questions that follow. (The letters do not represents the actual symbol of the elements) 

image

  1. What name is given to the group of elements to which C and F belong?               
  2. Compare the atomic radius of element C and F. explain                                      
  3. Which letter represents the element that is the least reactive?                             
  4. What type of bond is formed when B and E react?  Explain                                   
  5. Write the formula of the compound formed when element and oxygen gas react.          
  6. On the grid, indicate with a tick the position of element G which is in the third period of the periodic table and forms G3- ions                                                          

(b) The table below gives the number of electrons, protons and neutrons in substances X, Y and Z. 

Study it and answer the questions that follow.    

Substance

electrons

protons

neutrons

X

10

10

10

Y

10

8

10

Z

8

8

8

 

(i) Which element represents and Ion

(ii) Which of the substances are isotopes? Give a reason.

 

5.(a) An organic compound P consist of 52.2% of carbon, 13% of hydrogen and 34.8% of oxygen. The vapour density of P is 23. Calculate the molecular formula of the compound P and write possible isomer(s) from the molecular formula determined.


 (b) Hydrogen peroxide breaks down slowly to form water and oxygen; the reaction can be speed up by using a catalyst.

  1. How does the catalyst speed up the rate of reaction?
  2. Name a possible catalyst that can be used to speed up the reaction.
  3. Show that the catalyst always remains unchanged at the end of the reaction.

6.(a) Briefly explain the following

(i) Nitrogen gas is a necessary component of atmosphere

(ii) Nitrogen I Oxide is also called a Laughing gas

(iii) When carbon dioxide is passed through lime water, it turns milky

(iv) Things made of iron rust faster in coastal towns like Dar es salaam than in areas like Dodoma.

(v) Laboratory should have large windows

 

7.Using a well labelled diagram, explain how simple distillation can be used to separate a mixture of water and alcohol.

8. (a)What properties of hydrogen gas that made it to be used in the following?

i. As a fuel 

ii. To fill weather balloons 

iii. Manufacture of hydrochloric acid

iv. Manufacture of margarine 

(b) Environmental pollution in most of rural areas in Tanzania is caused by using charcoal and firewood as a fuel. What will be the two alternative source of energy, they supposed to use for environmental conservation? (give reason for each)

(c) Why fossil fuels are referred to as non-renewable energy resources? (Give two reasons)

 

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

Write the systematic name for the table salt

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

(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 

(ii) Molecular formula 

 

10. (a) Most of laboratory apparatuses are made up of glass materials. Why? (Give three reasons)

(b) Briefly explain how to handle chemicals having the following warning signs.

(i) Flammable

(ii) Corrosive

(c) Why luminous flame produces soot?

FORM TWO CHEMISTRY EXAM SERIES 143  

FORM TWO CHEMISTRY EXAM SERIES 143  

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. ………………………………………………………………………………………………………

 

 

FORM TWO CHEMISTRY EXAM SERIES 97  

FORM TWO CHEMISTRY EXAM SERIES 97  

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. ………………………………………………………………………………………………………

FORM TWO CHEMISTRY EXAM SERIES 57  

FORM TWO CHEMISTRY EXAM SERIES 57  

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.

FORM TWO CHEMISTRY EXAM SERIES 15  

FORM TWO CHEMISTRY EXAM SERIES 15  

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