Question

What is the reaction of freshly precipitated aluminium hydroxide with caustic soda solution? Give equation.

Answer 1

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

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