Question

State your observation, when excess sodium hydroxide is added to calcium nitrate solution.

Answer 1

• When excess sodium hydroxide $\left(\mathrm{NaOH}\right)$ is added to the calcium nitrate $\left[\mathrm{Ca}{\left({\mathrm{NO}}_3\right)}_2\right]$ solution, calcium hydroxide $\left[\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\right]$ and sodium nitrate $\left({\mathrm{NaNO}}_3\right)$ is produced.
• A white precipitate of calcium hydroxide is formed.

Chemical equation:

$\underset{\mathrm{Calcium}\mathrm{nitrate}}{\mathrm{Ca}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Sodium}\mathrm{hydroxide}}{2\mathrm{NaOH}\left(\mathrm{s}\right)}\to \underset{\mathrm{Calcium}\mathrm{hydroxide}}{\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Sodium}\mathrm{nitrate}}{2{\mathrm{NaNO}}_3\left(\mathrm{aq}\right)}$

Hence, when excess sodium hydroxide is added to the calcium nitrate solution, a white precipitate of calcium hydroxide is formed.