Question

Name a chloride of metal which is soluble in excess of ammonium hydroxide. What is the product formed?

Answer 1

• The chloride of metal which is soluble in excess of ammonium hydroxide is Zinc Chloride $\left({\mathrm{ZnCl}}_2\right)$.
• Tetraamine zinc (II) chloride is the end product, which is soluble and colourless.
• Firstly the white gelatinous $\mathrm{Zn}(\mathrm{OH}{)}_2$ is obtained which dissolves in excess ${\mathrm{NH}}_4\mathrm{OH}$ to form the product.
• The reaction is shown below.

${\mathrm{ZnCl}}_2\left(s\right)+2{\mathrm{NH}}_4\mathrm{OH}\left(l\right)\to \mathrm{Zn}(\mathrm{OH}{)}_2\left(s\right)\downarrow 2{\mathrm{NH}}_4\mathrm{Cl}(s)$