Question

An electric current is passed through an aqueous solution of lithium bromide.
What are 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 already learn in the videos that Electrode at which oxidation happens is anode and where reduction happens is cathode.
So here at cathode Li produces and at anode bromine produces.