Question

Name one metal hydroxide which is soluble and insoluble in sodium hydroxide.

Answer 1

• The hydroxide of lead is soluble in sodium hydroxide.
• Lead hydroxide dissolves in sodium hydroxide and will produce sodium plumbite and water. $$\begin{gathered} \mathrm{Pb}{\left(\mathrm{OH}\right)}_2\left(\mathrm{s}\right)+2\mathrm{NaOH}\left(\mathrm{aq}\right)\to {\mathrm{Na}}_2{\mathrm{PbO}}_2\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ \mathrm{Lead}\mathrm{hydroxide}\mathrm{sodium}\mathrm{hydroxide}\mathrm{Sodium}\mathrm{plumbite}\mathrm{water} \end{gathered}$$
• The hydroxide of magnesium(magnesium hydroxide) ($\mathrm{Mg}{\left(\mathrm{OH}\right)}_2$) is insoluble in sodium hydroxide.