Question

Q 3. What happens when:
(a) Copper sulphate solution is electrolysed by using copper electrodes
(b) A concentrated volatile acid is treated with a non-metal
(c) A concentrated dilute volatile acid is treated with metallic carbonate.

Answer 1

The solution is as follows:

Answer 3:

(a) When copper sulphate is electrolysed using copper electrodes, the negative cathode terminal gets thicker while positive anode terminal gets thinner. The reactions are:


Cathode: Cu²⁺ (aq) + 2e^- $\to$Cu (s)
Anode: Cu (s) $\to$ Cu²⁺(aq) + 2 e^-

(b) Acids do not react with non-metals. There is no reaction.

(c) We observe effervescence when metallic carbonates are treated with volatile acid. The reaction is:

2 HCl (aq) + Na₂CO₃(aq) $\to$ 2 NaCl (aq) + CO_​2 (g) + H₂O (l)