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Chemistry Paper 2


1(a) E (1mrk)
Its ions have the greatest tendency to accept electrons // Has the highest positive electrode potential // Ions
are strongest oxidizing agent

(ii) NB: The arrow should be on the wire or electrode but not outside the diagram.
(iii).To complete the circuit // maintain change balance // replace ions used up in half cells. (1mrk)
C (i) OH- ions migrate to the anode(1mrk). OH- ions are preferentially discharged to form O2 gas. // OH- ions oxidized to form O2 (g)(1mrk)

(ii) Copper anode dissolves to give Cu2+(aq) // Copper anode is oxidized (1mrk) this is because oxidation of copper requires lesser energy than oxidation of OH-

13 marks


(a) (i) Dehydration (1mrk)

(ii) Warm // Heat½ // presence of Conc.H2SO4½
(iii) Chloro-ethene
(iv) Ethanol / CH3CH2OH(l)

(b) (i) C2H4O2 ½ it has a melting point of 289.6K which is higher than 283.0K½
(ii) C3H8O is more soluble in water than C5H12.This is because C3H8O hydrogen bonds which improves it solubility while C5H12 does not hydrogen bond

13 marks


.(a)(i) On the grid [ period 3 and group 4]

(ii) L (1mrk). Atomic radius decreases across a period from left to right // The nuclear charge or no. of protons increase across the period hence electrons are strongly attracted towards nuclear

b) Q is more reactive with sodium than R.(1mrk) This is because. Q has a higher tendency to accept electrons
than R// Q is more electronegative than R

d). In bulbs to provide an inert atmosphere so as to minimize the rate of oxidation of filament. (mrk

11 marks


(ii) The amount of heat given out when one mole of a substance is completely burnt in excess oxygen at standard conditions

(iii)Heating value is – 40.32 kilo joules.// the heat given out when 1g of butane is burnt.

11 marks


a)(i) To remove the metal oxide layer which interfere with reaction

b).(i) Graph:
-Labeling and axis (correct) – (1mrk)
- Plotting [all points correct] – (1mrk)
- Smooth Curve – (1mrk)

12 marks


ii) – In treatment of drinking water
-Manufacture of chloroform aneasthetic
-Manufacture of germicide, fungicides and pestcides

11 marks

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