Question

An electric current is passed through an aqueous solution of lithium bromide.
What is produced at the cathode and anode respectively?

• A. Cathode –Lithium, Anode - bromine
• B. Cathode –bromine, Anode - lithium
• C. Cathode –Lithium, Anode - lithium
• D. Cathode –bromine, Anode - bromine

Answer 1

The correct option is A

Cathode –Lithium, Anode - bromine

In Lithium Bromide, lithium exists as $L{i}^{+}$ and bromine as $B{r}^{-}$.
$L{i}^{+}$reduces to Li and
$B{r}^{-}$oxidizes to Br.
Reactions are as follows
$L{i}^{+}+e^{-}\to Li$ (reduction)
$2B{r}^{-}\to B{r}_2+2e^{-}$ (oxidation)
We have already learned in the videos that Electrode at which oxidation happens is the anode and where reduction happens is the cathode.
So here at cathode Li produces and at anode bromine produces.