The question was popular among the candidates and the performance was fair.
In (a)(i) and (ll), candidates correctly defined oxidation as the process of electron loss and reduction as the process of electron gain. A few number of the candidates however lost marks because they defined the 'terms with respect to oxygen and hydrogen.
In (b)(i) I and IT, majority of the candidates were able to correctly determined the oxidation state of phosphorous as follows:

(i) POCl3
P = (-2) + 3 (-1) = 0 P-2-3=0
P =+5

(ii) PH3
P+3 (-1).=0 P-3+0 P=+3

However, some of them lost marks because they failed to assign the sign (+).
In b(ii), most candidates correctly stated that NaN03, Nl-4CI and Na2C03 ·were neutral, acidic and basic respectively but could not give the required reasons. The expected responses from candidates were:
(I).  NaNO3    -   Neutral
It is a salt of a strong acid and a strong base/ions do not undergo hydrolysis
(II).  NH4Cl  -   Acidic
It is a salt of a strong acid and a weak base/ NH4 + or cation undergoes Hydrolysis.
(III).  Na2CO3    -  Basic
It is a salt of weak acid and a strong base/ C032- or anion undergoes hydrolysis.

In (c), majority of the candidates correctly gave the answers to (i) - (vi) as follows:
             (i)         hydrogen chloride gas/HC1(g)
             (ii)        downward delivery/Upward displacement of air
             (iii)       the gas is denser than air
             (iv)       drying/purification of the gas
             (v)        Physical properties
                         - denser than air .
- very soluble in water
- fumes in moist air
- colourless gas
Chemical properties
- turns moist blue litmus red
- does not support combustion
- gives cloud of white fumes in contact with NH3 vapour.
            (vi)      Pass the gas into AgN03(aq) a white precipitate of AgCI is formed (which is soluble in NH3 but insoluble in NH03.

OR

Bring the gas into contact with ammonia, white fumes is given off.
However, some of them lost marks because they gave Cl2 or Chlorine gas as the gas produced in the experimental set-up. Also, few of them in (v), considered change in moist litmus paper from blue to red as a physical property hence lost the mark.
In (d), candidates correctly calculated the value of x in the hydrated salt Na2S04xH20 when heated as follows:
            Mass of water   4.30g-2.12g          = 2.18g
            Mass ofNa2S04   23 x 2 + 32 + 16 x 4 = 142
            Molar mass of      2 + 16 = 18
2.12g of anhydrous salt contain 2.18g of water
142g of anhydrous salt contain                       2.18x142 = 146.018
                                                                                 2.12
                        x(H2O) =         146
                        18x      =          146
                             x     =          146      =          8
                                                 18
(Any other correct method was accepted).