THE UNITED REPUBLIC OF TANZANIA PRESIDENT’S OFFICE - REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

LUDEWA DISTRICT COUNCIL

FORM TWO MOCK EXAMINATION 2022

032 CHEMISTRY

TIME: 2:30 Hours 8th JUNE 2022

INSTRUCTIONS

i. This paper consists of section A, B and C

ii. Answer All questions in all sections

iii. Calculators and cellular phone are Not allowed in examination room

iv. Write your number on every page on every page on space provided

v. Constants used;-

H=1, C=12, O=16, Ca=40, Cl=35.5, K=39 ,Na=23 , N=14

SECTION A (15 Marks)

Answer all questions from this section

1. From item (i-x), choose the correct item from the given alternatives and write its answer beside the item number provided.

i. A form two student was preparing different types of mixtures in the chemistry laboratory. The first mixture, he dissolved 30grams of sodium chloride crystals (NaCl) in 500cm3 of water then he stirred the mixture for about five minutes. What is the name of this mixture prepared by a student?

1. Heterogeneous mixture
2. Suspension mixture
3. Colloidal mixture
4. Homogenous mixture

ii. One student from form one observed that most of the kitchen tools such as plates, cups, bowl and jugs are made of steel which is smooth and shiny. As a chemistry student why these kitchen tools are made up by such steel?

1. To make them look expensive
2. To make them shiny
3. To prevent them from rusting
4. To make easy to see

iii. Kimbe was doing experiment concerning flame test of different chemical substances in the chemistry laboratory, unfortunately his laboratory coat caught fire .Which of the following fire extinguishing items will you use to help him to extinguish fire from his laboratory coat?

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

iv. An element H with valency of 2 react with another element L with valency of 3. What is the probable chemical formula between atoms of element H and element L?

1. H₂L₃
2. L₂H₃
3. H₃L₂
4. HL₂

v. Jackline when was mopping chemistry laboratory she saw a sign of cross on a plastic bottle containing a certain chemical. Which of the following is the correct answer about the interpretation made by Jackline concerning the property of chemical contained in the bottle?

1. Radioactive
2. Harmful
3. Toxic
4. Oxidant

vi. Form four students in a certain school were conducting experiment about volumetric analysis. In their experiment they were required to transfer three drops of methyl orange from the reagent bottles into the reacting vessels. Do you think which of the following apparatus they were using to transfer three drops of methyl orange from reagent bottle to reacting vessels?

1. Beaker
2. Burette
3. Spatula
4. Dropper

vii. Students from Lugarawa health training center were doing a scientific research about malaria in Njombe region. Which among the following scientific procedures they were using to accept or to reject their hypothesis made?

1. Conclusion
2. Data interpretation
3. Data analysis
4. Experimentation

viii. During the practical session one student mixed accidentally the iron fillings with sulphur powder. Assume you are the expert of chemistry which method will you use to obtain these two components of the mixture separately?

1. Piking
2. Filtration
3. Magnetization
4. Evaporation

ix. Boron is known to have two stable isotopes of atomic masses 10.016g and 11.013g. The isotopes normally exists in nature in the proportions of 20% and 80%respectively, from the data what is the average mass of Boron?

1. 10.81g
2. 10.62g
3. 10.51g
4. 10.58g

x. Laboratory technician wanted to know the liquid present in beaker labeled L left after experiment. He took two drops of liquid L and he decided to add it into petri dish containing white anhydrous copper (II) Sulphate crystals. Immediately after the addition of three drops of liquid L into petri dish containing the anhydrous copper (II) Sulphate crystals the mixture turned to blue colour. What is the name of liquid present in beaker labeled L?

1. Water
2. Acid
3. Salts
4. Base

ANSWERS

2. Match the items in list A with the responses in list B by writing the letter of the correct response beside the item number in the answer booklet provided.

ANSWERS

3. a) Most of farmers in the rural areas were interested to know how the knowledge of chemistry is necessary in agricultural activities. Assume you are a chemist; educate these farmers on the application of chemistry in agriculture by giving five points.

b) The headmaster of a certain school was bought a small box which had a sign of Red Cross. Most of form one students they did not have a knowledge about that box.by using knowledge that you have learnt from chemistry answer the following questions.

i. What is the name given to that box

ii. Briefly explain the functions of four possible items that can be found in a box

4. a) A laboratory technician advised students to use non-luminous flame when they are heating chemicals in the laboratory. As a form two student explain briefly four reasons why he encouraged students to use this kind flame?

b) Some people in the society believe that solving problems by using scientific procedure is the wastage of time and money. By using knowledge of chemistry that you have refute the statement by giving four points.

5. a) Assume you are given two gas jars, one gas jar containing gas A and another gas jar containing gas B. Gas A is used to fill balloons while gas be is used to by ocean deep divers.

i. What are the chemical test of gas A and gas B?

Gas A . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas B . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ii. Explain five uses of gas A in your daily life.

b) Mwahisa placed a yellow solid on a deflagrating spoon, ignited and then lowed the spoon into a gas jar of oxygen .The solid burnt vigorously with a yellow flame and finally the product was a pale yellow solid.

i. What is the name of the yellow solid that is burnt in oxygen

ii. Write the chemical formula of the pale yellow product formed

iii. Write the word equation for the reaction

6. a) During the rains many rivers fill with muddy water, which people use for drinking. This water has caused them to suffer from water borne diseases such as typhoid and diarrhea. Explain two simple methods that can be used to obtain clean water from these rivers muddy water.

b) One form one student from a certain school was given a task by her teacher to write the chemical symbols of the following elements; sodium, iron and chlorine. But the student did as shown below in 6b ( i, ii, and iii). Help him by identifying his mistakes and then write a correct symbol in each

i. Symbol of sodium is (So)

ii. Symbol of iron is (Ir)

iii. Symbol of chlorine is (CL)

7. a) A form one student from a certain school given a task by her teacher to state the type of fire extinguisher(s) that she will use to extinguish fire caused by the burning materials listed below. Unfortunately a student failed to attempt this question correctly. As a form two student help her to answer this question.

i. Burning curtain 

ii. A fire started by a short circuit in an electric iron

iii. A fire started by hot oil in a frying pan

iv. Fire started on a bucket containing sodium metal

b) Cars, motorcycles and corrugated iron sheets in coastal towns like Dar es Salaam, Tanga and Zanzibar are found to rust more quickly than in other cities in Tanzania like Songea, Njombe, Mwanza and Arusha. Why is this so?

8. a) A compound consists of 27% sodium, 16.5% nitrogen and 56.5% oxygen by mass. Calculate the simplest formula of the compound.

b) During the practical session, Asha found some bottles in the laboratory containing different chemical compounds with different chemical formulas, unfortunately she failed to write the IUPAC names of these chemical compounds. As form two student help her by writing the correct IUPAC names of these chemical compounds found by Asha on bottles in the laboratory.

i. KCl . . . . . . . . . . . . . . . . . .

ii. Na2SO₄ . . . .  . . . . . . . . . 

iii. CaCl₂ . . . . . . . . . . . . . . .

iv. AlCl₃ . . . . . . . . . . . . . . .

v. SF₆ . . . . . . . . . . . . . . . . .

9. a) Oxygen exists naturally in three different isotopes which are, ¹⁶₈O(99.76%), ¹⁷₈O(0.04%) and ¹⁸₈O(0.20%). Calculate the relative atomic mass of oxygen

b) Use the knowledge that you have complete the following table below by indicating the number of protons, electrons and neutrons of different atoms shown in the table below. The atomic number and mass number are given.

SECTION C: 15 MARKS

10. Nowadays the world is suffering from climatic changes which is caused by over dependent on forests as a source of fuels, and over production of waste materials that pollute our environment. To overcome this problem is through the use of renewable source of energy such as biogas produced from animal dungs and sewage wastes. As the expert of chemistry prepare a report to convince the community to use this gas produced by animal dungs as the alternative source of energy while they are conserving the environment.

Students Assesment Number_________________

THE PRESIDENT’S OFFICE REGIONAL ADMINISTRATION AND LOCAL GOVERNMENT

MOSHI MUNICIPAL COUNCIL

SECONDARY EDUCATION EXAMINATIONS SYNDICATE

032 CHEMISTRY

FORM TWO MOCK ASSESMENT

Tuesday 28th June 2022 Am Time 2:30Hours

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 (15Marks)

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. The welders prefers to use non luminous flame for their work simply because

1. It is available
2. it is easy to transport
3. produce very hot flame
4. can be made by kerosene

ii. Spatula in the laboratory is used for scoping what types of substances?

1. Liquid and gases 
2. solids and liquids
3. Powdery and gases 
4. Solids and powdery

iii. There are two particles inside the nucleus which one contributes the net change of that nucleus?

1. Dalton 
2. Protons
3. Electrons
4. Neutrons

iv. Why oxygen as one of the components of air Is unique?

1. It has ability to burn 
2. it support combustion
3. it is diatonic gas
4. combine with carbon dioxide

v. Why it is necessary to boil drinking water?

1. To make it tasteless 
2. To remove impurities
3. to kill micro-organism 
4. To make it taste less

vi. How do chemists refer to a mixture of milk and water?

1. Miscible solution 
2. Suspension
3. Immiscible solution 
4. Emulsion

vii. How can one prevent rusting in fragile instruments like camera?

1. By galvanization 
2. By using silica gel 
3. By using oil 
4. By using ethanol

viii. The oxidation state of metallic element is always

1. Negative 
2. Positive 
3. Zero 
4. Neutral

ix. Which of the following is not man-made product of applying chemistry?

1. Sugar 
2. Fertilizer
3. Milk
4. Vaccines

x. The atomic number of element R is 9 What is its electronic configuration?

1. 2:4:3 
2. 2:5:2
3. 2: 7 
4. 2:6:1

ANSWERS

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

ANSWERS

SECTION B: (70MARKS)

3. (a) Mrs. Msema kweli was addressing the villagers about use of water for economic values. What 4 values will she tell the villagers

(b) Is an air a mixture or a compound? Give 4 reasons

4. (a) Do your think there is any reasons for providing first Aid to the Victim? If yes give four reasons.

(b)State the uses of the following items in first aid Kit.

i. The pair of scissors

ii. The whistle 

iii. Petroleum Jelly 

iv.Sterile gauze

5. (a)State three sub- atomic particles and their respective charge.

(b)State the four modification of Dalton`s atomic theory

(c)Draw and write the electronic configuration for the atoms having the following atomic numbers.

(i) 4Be 

(ii)14Si

6. (a)Distinguish the following substances.

i. Homogenous mixture from heterogeneous mixture.

ii.Miscible from immiscible liquids.

iii. Saturated from unsaturated solution.

(b)Give two chemical tests for pure water

7. (a)Asha want to select a good fuel for domestic uses in her home what things should she considered? (Mention six (6)

(b)Classify the following fuel either primary or secondary fuel.

(i) Coke 

(ii)Crude oil

(iii)Kerosene

(iv)Natural gas 

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)You are provided with the following atoms, for each fill the informations below:-

(i) ^35.5Cl

protons = 

Neutrons=

Electrons=

(ii) ¹H

protons = 

Neutrons= 

Electrons=

(b) Define the following

i.Atom

ii. Energy

iii.Atomic number

v. Isotopes

SECTION C (15 MARKS)

10a)i. What do you understand by the word “Relative atomic mass”?

ii). Carbon has main isotopes,¹²₆C and ¹⁴₆C with relative abundances 98.89% and1.11% respectively. Calculate the relative atomic mass of Carbon.

b)i. Draw a diagram of laboratory preparation of oxygen gas from hydrogen peroxide and manganese IV oxide

(ii) Write the word equation for the reaction above (a)i

c) Answer the following questions with reference to the first 20 elements of the periodic table

i. Give the chemical symbol of element having:

• The smallest atomic size______________________________________________

• The largest atomic size _______________________________________________

ii.Identify the element which are:

• Metals having three shells of electrons each

• Metals having 1 electron in the valence shell

• Noble gases ___________________________________________________________

PRESIDENT’S OFFICE REGIONAL ADMINISTRATIVE AND LOCAL GOVERNMENT

TANZANIA HEADS OF ISLAMIC SCHOOLS COUNCIL

FORM TWO INTER ISLAMIC MOCK EXAMINATION

 032 CHEMISTRY  

TIME: 2:30 HOURS Monday, 27^th September 2021 p.m.

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.

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 ?

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

1. Filtration
2. Decantation
3. Decantation
4. Fractional distillation.

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

1. Irritant
2. Flammable
3. Oxidant 
4. Explosion.

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

1. Oxygen
2. Hydrogen
3. Nitrogen 
4. Carbondioxide.

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

1. The air hole is closed
2. The burner gas jet is big
3. The air hole is fully opened
4. The gas supply is poor.

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

1. Sodium and magnesium
2. Calcium and carbon
3. Magnesium and calcium
4. Boron and Beryllium.

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

1. MX₂
2. MX₆
3. X₂m
4. M₂X.

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

1. Carbon and chlorine
2. Aluminium and oxygen
3. Magnesium and oxygen
4. Sodium and chlorine.

(ix) One of the following can distinguish hydrogen gas from other gases: 

1. It burns and supports combustion
2. It is colourless and odorless 
3. It gives a smell of a rotten egg
4. It burns with pop sound.

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

1. Its components can be separated physically
2. Its composition varies from one place to another
3. Its properties depends on individual gases
4. 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.

Answer:

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:

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

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?

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

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

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

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

(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 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.

(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) SO₃^2- 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)

PRESIDENT’S OFFICE REGIONAL ADMINISTRATIVE AND LOCAL GOVERNMENT

KILOSA DISTRICT COUNCIL

 FORM TWO TERMINAL EXAMINATION

CODE: 032 CHEMISTRY

TIME: 2.30Hours. Tuesday August 25, 2020. 

Instructions

• This paper consists section A and B with a total of ten (10) questions

• Answer all questions in the spaces provided.

• All writing must be in black or blue ink except diagrams which must be in pencil.

• The following atomic masses may be used: N= 14, C= 12, H= 1, S= 32, O= 16, Cu= 63,Cl=35.5

SECTION A (20 MARKS)

Answer all questions in this section

1.This section consists of multiple choice items (i)-(x).Write down the letter of the most correct response for each question:

(i) Chemistry is one of the sciences which deals with:

1. The study of body cells 
2. Composition,properties and behavior of matter 
3. Chemical changes 
4. Physical changes 

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

1. Syrup making 
2. Removing bad smell 
3. Killing micro-organisms
4. Formation of suspension

(iii) The atomic number of an element is the:

1. Number of protons 
2. Mass number  
3. Number of neutrons
4. Number of protons and neutrons

(iv) The substance that can burn your skin is best described as:

1. Flammable 
2. Corrosive 
3. Toxic
4. Explosive

(v) Coloured substances can be separated through the process called:

1. Distillation 
2. Sublimation 
3. Filtration
4. Chromatography

(vi) When you melt a piece of iron ,it undergoes:

1. Combination 
2. Physical change 
3. Chemical change 
4. Sublimation 

(vii)When element R of Group I combines with element F of Group VI, the formula of compound formed is:

1. R₂F 
2. F₂R 
3. RF₂ 
4. RF

(viii) The apparatus which used to measure a fixed volume of 20cm³ or 25cm³ in the laboratory.

1. Measuring cylinder 
2. Beaker 
3. Burette 
4. Pipette 

(ix) The electronic configuration of sulphur is :

1. 2:8:6 
2. 2:8 
3. 2:7 
4. 2:8:5

(x) When oxygen combines with metals they:

1. Form properties 
2. Water 
3. form metallic oxides 
4. Rust

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

(b). Fill in the blanks with the correct answer.

(i) ………………Involves covering of iron with zinc layer by dipping in molten zinc.

(ii) A bond formed by electron sharing………………

(iii) …………… is a substance which cannot be split into two or more simpler substance by any chemical means.

(iv) Matter is made up of very tiny particles called ................................ 

(v) .......................supports the bunsen burner making it stable.

SECTION B (80 MARKS)

Answer All question in this section

3. (a) Define the following terms

(i) Compound

(ii) Mixture

(b) Write the names of the processes of changing of matter from one state to another:

(i) Liquid to Gas is...............................

(ii) Solid to Liquid is .........................

(iii) Gas to Liquid is ............................

(c). Give three difference between muddy water and carbondioxide

4. Study the diagram carefully and then answer the questions that follows.

(a) (i) Name the apparatus labelled B, C, D and G.

B……………….................................................................

C………………………………………………………….

D………………………………………………..................

G……………………………………………………..……

(ii) Name the gas E ………………………………………………….

(iii) What is the test of gas E ………………………………………

(iv) Give the function of each of the following

A…………………………………………………………………

F…………………………………………………………………

(b) Give the reason to why hydrogen is used in

(i) Manufacture of margarine……………………………………….

(ii) Filling Weather balloons………………………………………

5. (a) Define the term fuel..........................................................................

……………………………………………………..……………………

(b) 2210KJ was liberated when 0.05Kg of a biodiesel was heated. Calculate the energy value of the fuel (biodiesel).

6. (a) Write the chemical formula for each of the following compound

(i) Dinitrogen trioxide 

(ii) Aluminium oxide 

(iii) Iron(iii) cloride 

(iv) Nitric(v) acid 

(c) Give the IUPAC system name of the following chemical compounds:

(i)HClO₃………………………………………………

(ii) CuO………………………………………………..

(iii) P₂O₅………………………………………………

(c)Draw and give function of the following apparatuses:

7. (a) Give the meaning of the following;

(i) Radical

(ii) Valence

(iii) Oxidation number

(b) Find the oxidation state of the underlined element in the following compounds:

8. (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?

9. (a) Mr. Shing’weng’we took two beakers containing water and labeled the as beaker A and beaker B. He put one spoon of chalk powder in beaker A then he stirred to mix it and in beaker B he put one spoon of sugar and stirred to mix it. Give three differences between the mixture in beaker A and the mixture in beaker B.

(b) Name three different kinds of natural water:

(c) State three(3) uses of water in economic activities:

10.(a) Define the following terms:

(i) Empirical formula

(ii) Molecular formula

(b) A certain compound has a molecular mass of 60g and has the following percentage composition by weight: carbon 40%, hydrogen 6.67% and oxygen 53.3%. Calculate 

(i)The simplest formula of the compound:

(ii) The molecular formula