Question

What happens when nitric acid is added to eggshell? Give a reason for your observation.

Answer 1

Chemical reaction

• Eggshell is generally made up of calcium salt generally Calcium carbonate represented by the formula ${\mathrm{CaCO}}_3$.
• When nitric acid $\left({\mathrm{HNO}}_3\right)$ is added to eggshells then it forms Calcium nitrate and liberates carbon dioxide gas.

${\mathrm{CaCO}}_3\left(\mathrm{s}\right)+2{\mathrm{HNO}}_3\left(\mathrm{aq}\right)\stackrel{}{\to }\mathrm{Ca}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{aq}\right)$

Observations

A rapid effervescence is observed, as well as the production of gas (Carbon dioxide gas), which transforms milky lime water and extinguishes a brilliant splinter.