Question

Select the correct answer - A compound which during electrolysis in its molten state, liberates a reddish-brown gas at the anode.

Answer 1

Correct Answer: $\left(D\right)$ lead $\left(Ⅱ\right)$ bromide.

The reaction takes place during the electrolysis of molten lead $\left(Ⅱ\right)$ bromide are,

At cathode: $P{b}^{2+}+2e^{-}\to Pb$

At anode: $B{r}^{-}-e^{-}\to Br$

$Br+Br\to B{r}_2$

The overall reaction is
$PbB{r}_2\left(l\right)\to Pb\left(s\right)+B{r}_2\left(g\right)$

Here bromine gas evolves anode which has a reddish-brown colour.