Question

You are provided with two containers made up of copper and aluminum. You are also provided with solutions of dilute HCl, dilute HNO₃, ZnCl₂  and H₂O. In which of the above containers these solutions can be kept?

Answer 1

(A) When solutions are kept in copper container

(a) Dilute HCl

Copper does not react with dilute HCl. Therefore, it can be kept.

(b) Dilute HNO₃

Nitric acid acts as a strong oxidising agent and reacts with copper vessel, therefore cannot be kept.

(c) ZnCl₂

Zinc is more reactive than copper (Cu) therefore, no displacement reaction occurs and hence can be kept.

(B) When solutions are kept in aluminium containers

(a) Dilute HCl

Aluminium reacts with dilute HCl to form its salt and hydrogen
is evolved. Therefore, cannot be kept.

2Al + 6HCl → 2 AlCl₃ + 3H₂

(b) Dilute HNO₃

Aluminium gets oxidised by dilute HNO₃ to form a layer of Al₂O₃ and can be kept.

(c) ZnCl₂

Aluminium being more reactive than zinc can displace zinc
ion from the solution. Therefore, the solution cannot be kept.

2Al + 3ZnCl₂ → 2 AlCl₃ + 3Zn

(d) H₂O

Aluminium does not react with cold or hot water. Therefore,
water can be kept

Aluminium is attacked by steam to form aluminium oxide
and hydrogen

2Al (s) + 3H₂O (g) → Al₂O₃ (s) + 3H₂ (g)