Question

State one observation for the following:

(i) Excess ammonium hydroxide solution is added to lead nitrate solution.

Answer 1

When lead nitrate $\left(\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\right)$ reacts with an aqueous solution of ammonium hydroxide solution $\left({\mathrm{NH}}_4\mathrm{OH}\right)$ ,then a chalky white precipitate of lead hydroxide $\left(\mathrm{Pb}{\left(\mathrm{OH}\right)}_2\right)$ is formed.

• The reaction can be represented as:

$$\begin{gathered} \mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+2{\mathrm{NH}}_4\mathrm{OH}\left(\mathrm{aq}\right)\to 2{\mathrm{NH}}_4{\mathrm{NO}}_3\left(\mathrm{aq}\right)+\mathrm{Pb}{\left(\mathrm{OH}\right)}_2\downarrow \\ \mathrm{Chalky}\mathrm{white} \end{gathered}$$

This precipitate is insoluble in excess ammonium hydroxide.