Match each item in List A with a correct response in List B by writing its letter against the appropriate statement in the space provided. LIST A LIST B (i) Gas used in balloons A. Helium (ii) Process of preventing rust with oil B. Lubrication (iii) Element with atomic number 14 C. Silicon (iv) Apparatus for gas collection D. Gas jar (v) Gas that turns lime water cloudy E. Carbon dioxide (vi) Separates dyes in a mixture F. Chromatography (vii) Liquid used in thermometers G. Mercury (viii) Turns litmus paper blue H. Base (ix) Method to obtain pure sugar I. Crystallization (x) Element in group VI, period 3 J. Sulphur Answers: LIST A i ii iii iv v vi vii viii ix x LIST B

1. Gas used in balloons (1 alama)
2. Process of preventing rust with oil (1 alama)
3. Element with atomic number 14 (1 alama)
4. Apparatus for gas collection (1 alama)
5. Gas that turns lime water cloudy (1 alama)
6. Separates dyes in a mixture (1 alama)
7. Liquid used in thermometers (1 alama)
8. Turns litmus paper blue (1 alama)
9. Method to obtain pure sugar (1 alama)
10. Element in group VI, period 3 (1 alama)

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(a) Define the term neutralization. (b) Name the colours of indicators when they are in acidic or alkaline solution. INDICATOR ACID SOLUTION ALKALINE SOLUTION (i) Methyl Orange ................................ ................................ (ii) Litmus ................................ ................................ (iii) Phenolphthalein ................................ ................................ (c) Find the oxidation state or number of the following underlined elements: (i) Ca: ............................................................ (ii) NO₂ (N underlined): ............................................................ (iii) H₂S (S underlined): ............................................................ (iv) Na₂CO₃ (C underlined): ............................................................

1. Define the term neutralization. (1 alama)
2. Define the term neutralization. (0 alama)
3. Name the colours of indicators when they are in acidic or alkaline solution. INDICATOR ACID SOLUTION ALKALINE SOLUTION (i) Methyl Orange (ii) Litmus (iii) Phenolphthalein (0 alama)
4. Name the colours of indicators when they are in acidic or alkaline solution. INDICATOR ACID SOLUTION ALKALINE SOLUTION (i) Methyl Orange (ii) Litmus (iii) Phenolphthalein (1 alama)
5. Find the oxidation state or number of the following underlined elements: (i) Ca: (ii) NO₂ (N underlined): (iii) H₂S (S underlined): (iv) Na₂CO₃ (C underlined): (1 alama)
6. Find the oxidation state or number of the following underlined elements: Na₂CO₃ (C underlined): (0 alama)

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(a) Elements R and S in the Periodic Table have atomic numbers 6 and 7 respectively. (i) Which element has a higher ionization energy? (ii) Of the two elements, which one has larger atoms? (iii) Which type of bond forms when element R combines with chlorine? (iv) Find the charge of atom R after the reaction in question (iii). (b) Mention four uses of water in daily life. (c) Define the following: (i) Compound: (ii) Suspension:

1. Elements R and S in the Periodic Table have atomic numbers 6 and 7 respectively. (i) Which element has a higher ionization energy? (ii) Of the two elements, which one has larger atoms? (iii) Which type of bond forms when element R combines with chlorine? (iv) Find the charge of atom R after the reaction in question (iii). (1 alama)
2. Mention four uses of water in daily life. (1 alama)
3. Define the following: (i) Compound: (ii) Suspension: (1 alama)
4. Elements R and S in the Periodic Table have atomic numbers 6 and 7 respectively. Find the charge of atom R after the reaction in question (iii). (0 alama)
5. Mention four uses of water in daily life. (0 alama)
6. Define the following: Suspension: (0 alama)

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(a) Which method would you use to separate each of the following mixtures? (i) Mud mixed with water: (ii) Copper sulphate crystals mixed with sand: (iii) Sulphur mixed with iron filings: (iv) Kerosene mixed with water: (b) Write three differences between an element and a compound.

1. Which method would you use to separate each of the following mixtures? (i) Mud mixed with water: (ii) Copper sulphate crystals mixed with sand: (iii) Sulphur mixed with iron filings: (iv) Kerosene mixed with water: (1 alama)
2. Which method would you use to separate the following mixture? Kerosene mixed with water: (0 alama)
3. Write three differences between an element and a compound. (0 alama)

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(a) Classify each of the following chemical equations as displacement, combination, neutralization, decomposition, or precipitation: (i) 2Na(s) + Cl₂(g) → 2NaCl(s): (ii) BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq): (iii) H₂SO₄(aq) + 2NaOH(aq) → Na₂SO₄(aq) + 2H₂O(l): (iv) Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g): (v) CaCO₃(s) → CaO(s) + CO₂(g): (b) What is the use of the following apparatus? (i) Test tube: (ii) Delivery tube: (iii) Mortar and pestle: (iv) Burette: (v) Retort stand:

1. Classify the following chemical equation as displacement, combination, neutralization, decomposition, or precipitation: Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g): (0 alama)
2. Classify the following chemical equation as displacement, combination, neutralization, decomposition, or precipitation: CaCO₃(s) → CaO(s) + CO₂(g): (0 alama)
3. What is the use of the following apparatus? Burette: (0 alama)
4. What is the use of the following apparatus? Retort stand: (0 alama)

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(a) Draw a well labelled diagram of preparation of hydrogen gas. (b) What is the test for hydrogen gas? (c) State any three uses of hydrogen.

1. Draw a well labelled diagram of preparation of hydrogen gas. (0 alama)
2. What is the test for hydrogen gas? (0 alama)
3. State any three uses of hydrogen. (0 alama)

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(a) Define the term combustion. (b) Write down three examples of combustible substances. (c) Explain why water is not used to extinguish oil fires. (d) What do you understand by the following chemical warning terms? (i) Toxic: (ii) Flammable: (iii) Corrosive: (iv) Harmful:

1. Define the term combustion. (0 alama)
2. Write down three examples of combustible substances. (0 alama)
3. Explain why water is not used to extinguish oil fires. (0 alama)
4. What do you understand by the following chemical warning terms? Harmful: (0 alama)

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What is a mixture? Mention three mixtures found in daily life. Write the names of the following processes of changing matter from one state to another: (i) Liquid to gas: (ii) Solid to liquid: (iii) Gas to solid:

1. What is a mixture? (1 alama)
2. What is a mixture? (2 alama)
3. Mention three mixtures found in daily life. (3 alama)
4. Mention three mixtures found in daily life. (1 alama)
5. Write the names of the following processes of changing matter from one state to another: (i) Liquid to gas: (ii) Solid to liquid: (iii) Gas to solid: (1 alama)
6. Gas to solid: (1 alama)

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Write the chemical symbols for the following: (i) Sodium: (ii) Oxygen: (iii) Iron: (iv) Chlorine: (v) Potassium: Write the formulae for the following compounds: (i) Magnesium chloride: (ii) Sulphur dioxide: (iii) Calcium carbonate: (iv) Ammonia: (v) Sodium hydroxide: Write balanced equations for the following chemical reactions: (i) Aluminium + Oxygen → Aluminium oxide (ii) Sodium carbonate + Hydrochloric acid → Sodium chloride + Water + Carbon dioxide (iii) Decomposition of ammonium chloride (iv) Copper + Sulphuric acid → Copper(II) sulphate + Hydrogen (v) Potassium hydroxide + Nitric acid → Potassium nitrate + Water

1. Write the chemical symbols for the following: (i) Sodium: (ii) Oxygen: (iii) Iron: (iv) Chlorine: (v) Potassium: (1 alama)
2. Write the formulae for the following compounds: (i) Magnesium chloride: (ii) Sulphur dioxide: (iii) Calcium carbonate: (iv) Ammonia: (v) Sodium hydroxide: (1 alama)
3. Write balanced equations for the following chemical reactions: (i) Aluminium + Oxygen → Aluminium oxide (ii) Sodium carbonate + Hydrochloric acid → Sodium chloride + Water + Carbon dioxide (iii) Decomposition of ammonium chloride (iv) Copper + Sulphuric acid → Copper(II) sulphate + Hydrogen (v) Potassium hydroxide + Nitric acid → Potassium nitrate + Water (1 alama)
4. Chlorine: (1 alama)
5. Potassium: (1 alama)
6. Ammonia: (1 alama)
7. Sodium hydroxide: (1 alama)
8. Copper + Sulphuric acid → Copper(II) sulphate + Hydrogen (1 alama)
9. Potassium hydroxide + Nitric acid → Potassium nitrate + Water (1 alama)

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