Question

What do you observe when freshly precipitated aluminum hydroxide reacts with caustic soda solution? Give the equation.

Answer 1

When freshly precipitated ammonium hydroxide reacts with caustic soda solution, it forms sodium aluminate and water.

$$\begin{gathered} \mathrm{Al}{\left(\mathrm{OH}\right)}_3\left(\mathrm{s}\right)+\mathrm{NaOH}\left(\mathrm{aq}\right)\to {\mathrm{NaAlO}}_2\left(\mathrm{s}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ \mathrm{Aluminum}\mathrm{hydroxide}\mathrm{Sodium}\mathrm{hydroxide}\mathrm{Sodium}\mathrm{aluminate}\mathrm{Water} \end{gathered}$$