Question

(II) Write balanced chemical equation for the following:

Sodium hydroxide is added to freshly precipitated aluminium hydroxide.

Answer 1

• When freshly precipitated aluminium hydroxide $\mathrm{Al}{\left(\mathrm{OH}\right)}_3$ reacts with sodium hydroxide gives sodium aluminate salt because aluminium hydroxide is amphoteric hydroxide and in reaction with sodium hydroxide, it acts like acid so the reaction between them gives salt and water.

Reaction between aluminium hydroxide and sodium hydroxide :

$\mathrm{Al}{\left(\mathrm{OH}\right)}_3+\mathrm{NaOH}\to {\mathrm{NaAlO}}_2\downarrow +2{\mathrm{H}}_2\mathrm{O}$