Question

A mixture of NH₄Cl and NaCl can be separated by

(a) filtration

(b) distillation

(c) sublimation

(d) decantation

Answer 1

Answer is : (c) sublimation

A mixture of NH₄Cl and NaCl can be separated by the process of sublimation. In this process, solid directly changes to gaseous state without passing into liquid state. NH₄Cl sublimes to gaseous NH₃ and HCl upon heating whereas NaCl does not sublime, the reaction can be written as

NH₄Cl(s) → NH₃(g) + HCl(g)