Write the cathodic and anodic reactions when aqueous solution of $$\text{KNO}_3$$ is electrolysed by using Pt electrodes.

PLACEHOLDER ANSWER - the answer is two half-reactions. Neither $$\text{K}^+$$ nor $$\text{NO}_3^-$$ is discharged, so water is electrolysed. At the cathode, $$2\text{H}_2\text{O} + 2e^- \rightarrow \text{H}_2 + 2\text{OH}^-$$, and at the anode, $$2\text{H}_2\text{O} \rightarrow \text{O}_2 + 4\text{H}^+ + 4e^-$$. Hydrogen and oxygen are liberated in the volume ratio $$2 \colon 1$$.