Which of the following species are isoelectronic?

A measuring cylinder is used for:

Define the term base.

1. What is a compound? (2 mk)
2. Define the term base. (0 mk)
3. Mention three compounds used in daily life. (3 mk)
4. Name the colours of indicators when they are in acidic or alkaline solution. INDICATOR ACID SOLUTION ALKALINE SOLUTION (i) Litmus (ii) Phenolphthalein (iii) Methyl Orange (0 mk)
5. Write the names of the following processes of changing matter from one state to another: (2 mk)
6. Find the oxidation state or number of the following underlined elements: (i) K: (ii) SO₄²⁻ (S underlined): (iii) HNO₃ (N underlined): (iv) KMnO₄ (Mn underlined): (0 mk)

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Elements P and Q in the Periodic Table have atomic numbers 16 and 17 respectively.

1. Elements P and Q in the Periodic Table have atomic numbers 16 and 17 respectively. (i) Which element has a higher ionization energy? (ii) Of the two elements, which one has smaller atoms? (iii) Which type of bond forms when element P combines with hydrogen? (iv) Find the charge of atom P after the reaction in question (iii). (0 mk)
2. Write the chemical symbols for the following: (5 mk)
3. Mention four methods of separating mixtures. (0 mk)
4. Write the formulae for the following compounds: (5 mk)
5. Write balanced equations for the following chemical reactions: (10 mk)
6. Define the following: (i) Acid: (ii) Solution: (0 mk)

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Which method would you use to separate each of the following mixtures?

1. Which method would you use to separate each of the following mixtures? (i) Sand mixed with water: (ii) Iron filings mixed with sulphur powder: (iii) Ammonium chloride mixed with sand: (iv) Methanol mixed with water: (0 mk)
2. Write three differences between a solution and a suspension. (0 mk)

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Classify each of the following chemical equations as displacement, combination, neutralization, decomposition, or precipitation:

1. Classify each of the following chemical equations as displacement, combination, neutralization, decomposition, or precipitation: (i) 2Mg(s) + O₂(g) → 2MgO(s): (ii) AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq): (iii) HCl(aq) + KOH(aq) → KCl(aq) + H₂O(l): (iv) Cu(s) + 2AgNO₃(aq) → Cu(NO₃)₂(aq) + 2Ag(s): (v) 2H₂O₂(l) → 2H₂O(l) + O₂(g): (0 mk)
2. What is the use of the following apparatus? (i) Crucible: (ii) Tongs: (iii) Gas jar: (iv) Dropper: (v) Filter funnel: (0 mk)

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Draw a well labelled diagram of preparation of carbon dioxide gas.

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

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Define the term laboratory safety.

1. Define the term laboratory safety. (0 mk)
2. Write down three examples of laboratory accidents. (0 mk)
3. Explain why a fume cupboard is used in a laboratory. (0 mk)
4. What do you understand by the following chemical warning terms? (i) Flammable: (ii) Corrosive: (iii) Harmful: (iv) Explosive: (0 mk)

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3. (a) What is a compound? (b) Mention three compounds used in daily life. (c) Write the names of the following processes of changing matter from one state to another: (i) Solid to liquid: (ii) Liquid to solid: (iii) Gas to liquid:

1. What is a compound? (1 mk)
2. Mention three compounds used in daily life. (3 mk)
3. Write the names of the following processes of changing matter from one state to another: (i) Solid to liquid: (ii) Liquid to solid: (iii) Gas to liquid: (3 mk)

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4. (a) Write the chemical symbols for the following: (i) Aluminium: (ii) Phosphorus: (iii) Copper: (iv) Magnesium: (v) Fluorine: (b) Write the formulae for the following compounds: (i) Calcium chloride: (ii) Nitrogen monoxide: (iii) Sodium carbonate: (iv) Hydrogen sulphide: (v) Potassium nitrate: (c) Write balanced equations for the following chemical reactions: (i) Magnesium + Oxygen → Magnesium oxide (ii) Sodium hydroxide + Sulphuric acid → Sodium sulphate + Water (iii) Decomposition of potassium chlorate (iv) Iron + Chlorine → Iron(III) chloride (v) Calcium + Hydrochloric acid → Calcium chloride + Hydrogen

1. Gas used in fire extinguishers (1 mk)
2. Write the chemical symbols for the following: (i) Aluminium: (ii) Phosphorus: (iii) Copper: (iv) Magnesium: (v) Fluorine: (5 mk)
3. Process of coating iron with zinc (1 mk)
4. Write the formulae for the following compounds: (i) Calcium chloride: (ii) Nitrogen monoxide: (iii) Sodium carbonate: (iv) Hydrogen sulphide: (v) Potassium nitrate: (5 mk)
5. Write balanced equations for the following chemical reactions: (i) Magnesium + Oxygen → Magnesium oxide (ii) Sodium hydroxide + Sulphuric acid → Sodium sulphate + Water (iii) Decomposition of potassium chlorate (iv) Iron + Chlorine → Iron(III) chloride (v) Calcium + Hydrochloric acid → Calcium chloride + Hydrogen (5 mk)
6. Element with atomic number 17 (1 mk)
7. Apparatus for precise liquid measurement (1 mk)
8. Gas that relights a glowing splint (1 mk)
9. Separates liquids with different densities (1 mk)
10. Liquid used in antiseptics (1 mk)
11. Turns anhydrous copper sulphate blue (1 mk)
12. Method to test for proteins (1 mk)
13. Element in group IV, period 2 (1 mk)

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