This question was on electrolysis (conduction of electricity through liquids).  Many candidates attempted the question and performed fairly well.  However, many of the candidates could not answer 4(a) satisfactorily.  The expected answers are:

Factors that determine the mass of an element deposited or liberated
 
            e.g       -          current passed
                         -          time of passage of current.
            (Accept quantity of electricity/charge passed)