Match the effects of environmental pollution in List A with the respective causes in List B by writing the letter of the correct response besides the item number in the answer booklet provided. List A (i) Ozone layer depletion (ii) Green House effect (iii) Eutrophication (iv) Terrestrial pollution (v) Acidic rain (vi) Water pollution List B A Biological Oxygen Demand B Biomass sludge C Sulphur dioxide D Chlorine atom E Liquid effluents F Calcium Ammonium Nitrate G Methane H Ultra Violet Radiation

1. Ozone layer depletion (0 alama)
2. Green House effect (0 alama)
3. Eutrophication (0 alama)
4. Terrestrial pollution (0 alama)
5. Acidic rain (0 alama)
6. Water pollution (0 alama)

Boresha ili kuona majibu ya mfano.

To investigate the solubility of sodium chloride, a technician dissolved different amount of sodium chloride in a specific volume of water while altering the temperature of water. What does temperature represent in this experiment?

Which property is used to confirm the presence of pure water?

The products formed when most non-metals burn in oxygen can react with water to form solutions which turn blue litmus paper red. With the aid of chemical equations, show the validity of this statement using carbon as non-metal. (b) (i) Give three properties of oxygen gas. (ii) Give three uses of oxygen gas based on the properties mentioned in (b) (i).

1. The products formed when most non-metals burn in oxygen can react with water to form solutions which turn blue litmus paper red. With the aid of chemical equations, show the validity of this statement using carbon as non-metal. (4 alama)
2. Give three uses of oxygen gas based on the properties mentioned in (b) (i). (0 alama)

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(a) Why is Bunsen burner a preferable source of heat in the chemistry laboratory? Give four points. (b) Suggest five sources of heat that can be used in a chemistry laboratory apart from Bunsen burner.

1. Why is Bunsen burner a preferable source of heat in the chemistry laboratory? Give four points. (4 alama)
2. Suggest five sources of heat that can be used in a chemistry laboratory apart from Bunsen burner. (5 alama)

Boresha ili kuona majibu ya mfano.

(a) Which processes can be used to separate or extract each of the following substances? () Mixture of iodine and sand (ii) Mixture of cooking oil and water (iii) Mixture of sodium chloride and water (iv) Oil from seed (v) Mixture of ethanol and water (vi) Mixture of sand and water (b) Briefly explain application of chromatography process in daily life. Give six points.

1. Oil from seed (0 alama)
2. Mixture of sand and water (0 alama)
3. Briefly explain application of chromatography process in daily life. Give six points. (7 alama)

Boresha ili kuona majibu ya mfano.

(a) What are the sources of organic acids? Give five points. (b) Identify two products which can be formed in each of the following processes: (i) Reaction of sodium with ethanol. (ii) Partial fermentation of sucrose in presence of yeast cells.

1. What are the sources of organic acids? Give five points. (5 alama)
2. What are the sources of organic acids? Give five points. (5 alama)
3. Identify two products which can be formed in each of the following processes: (i) Reaction of sodium with ethanol. (ii) Partial fermentation of sucrose in presence of yeast cells. (3 alama)
4. Partial fermentation of sucrose in presence of yeast cells. (0 alama)

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(a) Why is it important to replace fossil fuels as an energy source? (b) Briefly explain four alternative sources of energy that can be developed to replace the fossil fuels.

1. Ozone layer depletion (1 alama)
2. Why is it important to replace fossil fuels as an energy source? (4 alama)
3. Why is it important to replace fossil fuels as an energy source? (3 alama)
4. Briefly explain four alternative sources of energy that can be developed to replace the fossil fuels. (6 alama)
5. Briefly explain four alternative sources of energy that can be developed to replace the fossil fuels. (5 alama)
6. Green House effect (1 alama)
7. Eutrophication (1 alama)
8. Terrestrial pollution (1 alama)
9. Acidic rain (1 alama)
10. Water pollution (1 alama)

Boresha ili kuona majibu ya mfano.

(a) How is the concept of mole useful in Chemistry? Give four points. (b) What mass of impure ammonium chloride (90%) would be needed to react completely with 14.8g of calcium hydroxide?

1. How is the concept of mole useful in Chemistry? Give four points. (4 alama)
2. How is the concept of mole useful in Chemistry? Give four points. (4 alama)
3. What mass of impure ammonium chloride (90%) would be needed to react completely with 14.8g of calcium hydroxide? (6 alama)
4. What mass of impure ammonium chloride (90%) would be needed to react completely with 14.8g of calcium hydroxide? (5 alama)

Boresha ili kuona majibu ya mfano.

Suggest five sources of heat that can be used in a chemistry laboratory apart from Bunsen burner.

1. Suggest five sources of heat that can be used in a chemistry laboratory apart from Bunsen burner. (5 alama)

Boresha ili kuona majibu ya mfano.

Which processes can be used to separate or extract each of the following substances?

1. Mixture of iodine and sand (1 alama)
2. Mixture of cooking oil and water (1 alama)
3. Mixture of sodium chloride and water (1 alama)
4. Oil from seed (1 alama)
5. Mixture of ethanol and water (1 alama)
6. Mixture of sand and water (1 alama)

Boresha ili kuona majibu ya mfano.

Briefly explain application of chromatography process in daily life. Give six points.

1. Briefly explain application of chromatography process in daily life. Give six points. (6 alama)

Boresha ili kuona majibu ya mfano.

The following diagram was used to study the reaction of calcium and water. Gas X Water Calcium Turnings Gas X produced was passed through black copper(II) oxide which changed colour to brown. With the aid of a chemical equation, interpret this observation. (b) Hydrogen atom can react by either gaining or loosing electron. In both cases, energy is involved. With the aid of the chemical equation(s) and energy level diagram, interpret this observation.

1. Give three properties of oxygen gas. (3 alama)
2. Gas X produced was passed through black copper(II) oxide which changed colour to brown. With the aid of a chemical equation, interpret this observation. (7 alama)
3. Gas X produced was passed through black copper(II) oxide which changed colour to brown. With the aid of a chemical equation, interpret this observation. (7 alama)
4. Hydrogen atom can react by either gaining or losing electron. In both cases, energy is involved. With the aid of the chemical equation(s) and energy level diagram, interpret this observation. (8 alama)
5. Hydrogen atom can react by either gaining or loosing electron. In both cases, energy is involved. With the aid of the chemical equation(s) and energy level diagram, interpret this observation. (8 alama)

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How is organic manure important to soil quality? Briefly explain by giving five points.

1. Give three uses of oxygen gas based on the properties mentioned in (b) (i). (3 alama)
2. How is organic manure important to soil quality? Briefly explain by giving five points. (15 alama)

Boresha ili kuona majibu ya mfano.

Give the explanation on the hydrogen chloride gas based on the following: (a) the raw material for production of the gas. (b) two chemical tests for hydrogen gas. (c) four physical properties of hydrogen chloride. (d) five uses of hydrogen chloride gas.

1. the raw material for production of the gas. (3 alama)
2. two chemical tests for hydrogen gas. (4 alama)
3. four physical properties of hydrogen chloride. (4 alama)
4. five uses of hydrogen chloride gas. (4 alama)

Boresha ili kuona majibu ya mfano.