Question

Describe the action of concentrated ${\mathrm{HNO}}_3$ on:
carbon

Answer 1

• Diluted nitric acid $\left({\mathrm{HNO}}_3\right)$ has no reaction with non-metals, and as carbon is a non-metal, dilute nitric acid has no effect on it.
• However, non-metals like carbon are oxidized to their oxy-acids by concentrated nitric acid, while nitric acid is reduced to nitrogen dioxide.
• As a result, we can claim that nitric acid converts carbon $\left(\mathrm{C}\right)$ to carbon dioxide(${\mathrm{CO}}_2$).
• Equation for above reaction is shown below:

$\underset{\mathrm{carbon}}{\mathrm{C}}+\underset{\mathrm{nitric}\mathrm{acid}}{4{\mathrm{HNO}}_3}\to \underset{\mathrm{carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2}+\underset{\mathrm{water}}{2{\mathrm{H}}_2\mathrm{O}}+\underset{\mathrm{nitrogen}\mathrm{dioxide}}{4{\mathrm{NO}}_2}$