Fats are classified as

• A. hydrocarbons
• B. alkanoates
• C. alkanols
• D. carbohydrates

(a)(i) List three observable changes that take place when a dilute solution of copper (II) chloride is electrolysed using platinum electrodes. Stage III

(ii) Calculate the quantity of electricity used during electrolysis when a current of 0.21 ampere flows for 2 hours.

(iii) State what is meant by the term preferential discharge of ions in electrolysis

(iv) Give one factor which influences the preferentia! discharge of ions during electrolysis.

(v) State one Q difference between-a conductor and an electrolyte.

(b) Consider the reaction represented by the equation below: Na\(_2\)S\(_2\)O\(_{3(aq)}\) + 2HCI\(_{(aq)}\) \(\to\) 2NaCI\(_{(aq)}\) + H\(_2\)O\(_{(l)}\) + SO\(_{2(g)}\) + S\(_{(s)}\)

(i) List two factors that can affect the rate of this reaction.

(i) Which of the products can be readily used to measure the rate of the reaction. Give a reason for your answer.

(iii) Name two instruments that can be used to measure factors in (b)(i) above.

(c)(i) State the reasons for regarding rusting and burning as oxidation processes.

(ii) I. Write the balanced half equations for the following redox reaction: Mg\(_{(s)}\) + Fe\(^{2+}_{(aq)}\) ----> Mg\(^{2+}_{(aq)}\) + Fe\(_{(s)}\)

II. Which of the reactants is the oxidizing agent?

Ill. State the change in the oxidation number of the oxidizing agent.

(d)(i) State one ore from which each of the following metals can be extracted. I. Tin II. Iron (ii) List two uses of copper (iii) Name one alloy of tin.

Ethyne undergoes the following reactions except

• A. polymerisation
• B. addition
• C. substitution
• D. esterification

(a) The electronic configurations of atoms of elements A, B, C and D are given as follows: A. Is\(^2\)2s\(^2\)2p\(^2\); B. 1s\(^2\)2s\(^2\)2sp\(^1\) ; C. 1s\(^2\)2s\(^2\) 2p\(^1\) ; D. 1s\(^2\) 2s\(^2\)

(I) Arrange the elements in order of increasing atomic size, giving reasons

(ii) State which of the elements I. is divalent II. contains atoms with two unpaired electrons in the grouped state. Ill, readily loses one electron from its atom during chemical bonding IV. belongs to group Ill in the Periodic Table.

(b)(i) State one difference between electrovalent and covalent bonds.

(ii) Name two other bonds apart from the ones in (b)(i) above which bind atoms and molecules together.

(iii) State two characteristics of a covalent compound.

(c)(i) What is isotopy?

(ii) Illustrate with suitable example

(iii) Two isotopes of Z with mass numbers 18 and 20 are in the ratio 1:2 Determine the relative atomic mass of Z.

(d)(i) Which of the following elements: calcium, fluorine, iodine neon, magnesium and helium are I. halogens II. noble gases Ill. alkaline earth metals.

(ii) Write a balanced equation for the bombardment of \(^7_3Li\) with protons to produce \(^8_4\beta\) and \(\gamma\)-rays

(iii) State one use of radioactive isotopes.

An element which can exist in two or more forms in the same physical state, exhibits

• A. isotopy
• B. structural isomerism
• C. allotropy
• D. variable valency

Hardness in water can be removed by adding

• A. copper (ll) tetraoxosulphate (IV)
• B. sodium trioxocarbonate (IV)
• C. sodium chloride
• D. alum

What is the mass number of an element having 20 neutrons, 15 protons and 15 electrons?

• A. 15
• B. 30
• C. 35
• D. 50

In which of the following processes is biotechnology not applied?

• A. Manufacture of drugs
• B. Treatment of domestic sewage
• C. Production of alcoholic beverages
• D. Electroplating of metals

The main difference between a primary cell and a secondary cell is that the primary cell

• A. is an electrolytic cell but the secondary is not
• B. cannot be recharged but the secondary cell can
• C. can be recharged but the secondary cell cannot
• D. contains electrodes but the secondary cell does not

(a)(i) State the two types of hardness in water.

(ii) Name a salt that causes each type of hardness.

(ii) Write a balanced equation for the removal of each type of hardness.

(iv) State one effect of hard water on soap.

(b)(i) State whether the pH of each of the following is less than, equal to, or greater than 7.

I. Glucose solution II. Chlroine water III. Lime water IV. Sour milk

(ii) Give the difference between the following compounds: I. an acidic oxide and an amphoteric oxide; II. concentrated acid and a dilute acid; Ill. a normal salt and an acid salt

(c)(i) Iron reacts with H\(_2\)SO\(_4\) according to the equation: Fe\(_{(s)}\) + H\(_2\)SO\(_{4(aq)}\) ---> FeSO\(_{4(aq)}\) + H\(_{2(g)}\)

Calculate the mass of FeSO\(_4\) that would be produced by 0.5 mole of Fe. [H = 1, S = 32, Fe = 56]

(ii) List two allotropes of sulphur

(d)(i) State what would La observed when a damp starch-iodide paper is dropped into a gas jar of chloride

(ii) Explain your ansv.er in (d)(i) above.

(iii) State the products formed when ammonia reacts with excess chlorine.