Question

G3-1: precipitation of group 3 cations by adding ammonium chloride, ammonia, and thioacetamide

Answer 1

Precipitation of the Group III Cations.

In the sulfides forms The ions of Group III are precipitated., or as their hydroxides, from a basic solution of hydrogen sulfide.

The sulfides of the ions of Group III are not sufficiently insoluble to be precipitated in the acidic solution of hydrogen sulfide of Group II but will be precipitated by basic solutions of hydrogen sulfide.

One of teh most important factor comes for the separation is thye common ion effect while tratting with the hydroxide ions.

olubility products of group (III) hydroxides are low as compared to the hydroxides of higher groups, so a low concentration of OH− ions is required to precipitate group (III) cations. Presence of NH4​Cl which is a strong electrolyte suppresses dissociation of weak electrolyte NH4​OH by common ion effect and decreases OH− ion concentration considerably..