This question was attempted by most candidates and the performance was good.
In (a), candidates correctly stated addition of Million’s reagent/Biuret/(NaOH/CuSO4)/
conc. HNO3 and heat as the reagent and condition used to identify proteins in the
laboratory.
In (b), candidates correctly calculated the mass of KOH required to produce 250cm3 of
0.02 moldm-3 solution thus:
(b) Molar mass of KOH = 39 + 16 + 1 OR 56gmol-1
Mass = concentration x volume x molar mass
= 0.02 moldm-3 x 0.25 dm3 x 56 gmol-3
= 0.28g
[other correct method was accepted]
In (c), candidates knew that separating funnel, fumes cupboard and spatula are used for separating two immiscible liquids, preparation of toxic/poisonous gases and scooping of solid/powdered reagents respectively
