Question

10 mL of freshly prepared iron sulphate was taken in each of four test tubes.

Strips of copper, iron, zinc and aluminium were introduced, each metal in a

different test tube. A black residue was obtained in two of them. The right pair of

metals forming the precipitates is

a
Copper and zinc.

b
Aluminum and copper.

c
Iron and aluminium.

d
Zinc and aluminium.