Question

Name the metal salts which are:

(a) sparingly soluble (b) insoluble

(c) soluble

in Ammonium hydroxide solution.

Answer 1

Part-1

• Ammonium hydroxide $\left({\mathrm{NH}}_4\mathrm{OH}\right)$ reacts with Copper, Iron, Zinc, and Lead.
• Some of them are soluble because of the formation of soluble Amino complex

Part-2

• Calcium $\left(\mathrm{Ca}\right)$ salt is sparingly soluble as the ionization of Ammonium hydroxide $\left({\mathrm{NH}}_4\mathrm{OH}\right)$ is very slow in calcium salt solution
• Lead $\left(\mathrm{Pb}\right)$ salt is insoluble as it forms a white precipitate when reacting with Ammonium hydroxide $\left({\mathrm{NH}}_4\mathrm{OH}\right)$.
• Copper$\left(\mathrm{Cu}\right)$ salt solubilizes in Ammonium hydroxide $\left({\mathrm{NH}}_4\mathrm{OH}\right)$ as it first gives a precipitate and then solubilizes in the Ammonium hydroxide to give deep blue color.

Final Answer -

(a) Sparingly soluble - Calcium $\left(\mathrm{Ca}\right)$ salt

(b) Insoluble - Lead $\left(\mathrm{Pb}\right)$ salt

(c) Soluble - Copper$\left(\mathrm{Cu}\right)$ salt