Question

What is electrolysis of water?

Answer 1

Electrolysis

• The process of decomposing ionic substances into simpler substances when an electric current is passed through them is known as electrolysis.
• Electrolysis is used to coat one metal over another.
• Metals used in industry include aluminum $\left(\mathrm{Al}\right)$, and magnesium $\left(\mathrm{Mg}\right)$ for electrolysis.

Electrolysis of water

• The chemical reaction of passing an electric current through water to decompose hydrogen and oxygen gases is known as the electrolysis of water.
• The reaction is as follows:
• $2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\stackrel{\mathrm{Electrical}\mathrm{current}}{\to }{\mathrm{O}}_2\left(\mathrm{g}\right)+2{\mathrm{H}}_2\left(\mathrm{g}\right)$
• As a result, the number of hydrogen molecules produced is double that of oxygen molecules.
• Hydrogen is collected at the negative anode after water electrolysis, while oxygen is collected at the positive anode.
• The half cell reaction is as follows:

$$\begin{gathered} \mathrm{Cathode}:2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2\left(\mathrm{g}\right)+2{\mathrm{OH}}^{-}\left(\mathrm{aq}\right) \\ \mathrm{Anode}:2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{O}}_2\left(\mathrm{g}\right)+4{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+4{\mathrm{e}}^{-} \end{gathered}$$