KCSE Past Papers 2014 Chemistry paper 2 (233/2)

Chemistry Paper 2 (233/2)

1 – (i)Sodium chloride / potassium chloride /rock salt.( 1 mark)

(ii) Concentrated sulphuric (VI) acid( 1 mark)

(iii) Grey solid turns green( 1 mark)

( 1 mark)

(V)To avoid explosion.( 1 mark)

(b) (i) I The gas reacts with silver nitrate to form insoluble silver chloride.( 1 mark) II Both gases form ammonium chloride which is white.( 1 mark)

(ii)- To make hydrochloric acid.( 1 mark)

– Manufacture of ammonium chloride.( 1 mark)

– Manufacture of PVC.( 1 mark)

– Making chloroethene /vynil chloride( 1 mark)

(c)(i)imagee

(ii) Presence of Ca2+ which make water hard / forms scum. ( 1 mark)

2. (i)K – Has largest atomic radius / it most readily loses its outermost electron.( 1 mark) (ii) B/N( 1 mark)

(iii) D/Mg( 1 mark)

(iv) A (1 ) It has the smallest/smaller atomic rad1us/ its outermost electron is more/most strongly held by nucleus.(1)( 2 mark)

(v) PH is seven (7). The chlorides of group 1 elements are neutral salts.(2 marks)

(b) (i) Both CaCl2 and MgCl2 have mobile ions in molten state (1) while both CCl4 and SiCl4 are molecular compounds with no mobile ions (1).

(ii) Neon has molar mass of 20 While Flourine has a molar mass of 38 (l).

Therefore Neon diffuses faster. (l) Since it has a lower molecular mass the faster the rate of diffusion.

3

(d) Fuel

Solvent

Anti-septic

Manufacture of synthetic fibres

Manufacture of gasohol

Manufacture of ethanoic acid/vinegar

Used in themometers

Manufacture of other organic compounds.

Any 2 (2 marks)

4. (a) -Pressure

-Concentration

-Catalyst

-Particle size/surface area

-Light intensity (1 mark)

(b) (i)Draw a tangent to the graph at L12 min. (1) _

-Determine change in volume( Y) /Calculate gradlem

-Determine change in time.( Y)

-Divide change in volume by change in time (1)

(ii)AB Low production of gas(1) while BC the rate is very high because catalyst B was added.(1)

(iii)

(c) (i) Lowering the temperature shifts the equilibrium to the right /favours the forward reaction. (1) Hence more S03 will be produced. (1)

(ii) Platinum or Vanadium pentoxide/vanadium (v) oxide / V2O5/ platinised asbestos any (1 mark)

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