Question

Write the balanced chemical equation for the following reaction:

Actions of hot and concentrated Nitric acid on Copper.

Answer 1

Reaction between Copper and concentrated Nitric acid:

Copper turning test: Detection of nitrate ions

• When mixture of Copper $\left(\mathrm{Cu}\right)$ and conc. Nitric Acid $\left({\mathrm{HNO}}_3\right)$ is heated , it will give Copper nitrate $\left(\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\right)$ , water $\left({\mathrm{H}}_2\mathrm{O}\right)$ & Nitrogen dioxide gas $\left({\mathrm{NO}}_2\right)$ as a product.
• The evolution of brown gas nitrogen dioxide takes place.

Balanced chemical equation :

$\underset{\mathrm{Copper}}{\mathrm{Cu}\left(\mathrm{s}\right)}+\underset{\mathrm{Nitric}\mathrm{Acid}}{4{\mathrm{HNO}}_3\left(\mathrm{aq}\right)}\stackrel{∆}{\to }\underset{\mathrm{Copper}\mathrm{nitrate}}{\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}+\underset{\mathrm{Nitrogen}\mathrm{dioxide}\mathrm{gas}}{2{\mathrm{NO}}_2\left(\mathrm{g}\right)}$