Question

How would you obtain pure ammonium chloride solution when it contains potassium chloride as an impurity?

Answer 1

Sublimation: In this process, a sublimate substance changes its state from solid to gas directly without passing through a liquid state on heating.

Separation of Pure Ammonium chloride$\left({\mathrm{NH}}_4\mathrm{Cl}\right)$ from Potassium chloride$\left(\mathrm{KCl}\right)$:

• A mixture of ammonium chloride can be separated from the solution of potassium chloride and ammonium chloride using the process of sublimation.
• The sublimable temperature of ammonium chloride is the lowest as it is $520°\mathrm{C}$ so it will sublimate first.
• And separated into different containers after cooling.
• Then potassium chloride with a boiling point $758.8°\mathrm{C}$ will be left behind in the container.

Therefore, we can obtain pure ammonium chloride solution when it contains potassium chloride as an impurity using the sublimation method.