Question

In the Electrolysis of acidulated water, _______ gas is evolved at the anode

Answer 1

The gas formed at the anode:

• The process of using electricity to split water into hydrogen and oxygen is known as electrolysis.
  $\underset{\mathrm{Water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\to \underset{\mathrm{Hydrogen}}{2{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}$
• ${\mathrm{OH}}^{-}$ being negatively charged, moves towards the anode (positively charged electrode), that is Oxygen gas is released at the anode.
• The reaction at anode OH − ion

$$\begin{gathered} {\mathrm{OH}}^{-}\to \mathrm{OH}+{\mathrm{e}}^{-} \\ 4\mathrm{OH}\to 2{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2 \end{gathered}$$

Therefore, in the electrolysis of acidulated water, oxygen gas is evolved at the anode.