Question

A mixture contains iodine, ammonium chloride and sand. Only iodine and ammonium chloride are sublime. Only iodine dissolves in carbon tetrachloride. How will you separate the three components? The sequence of steps will be:

• A. By sublimation and addition of ${\mathrm{CCl}}_4$
• B. Addition of ${\mathrm{CCl}}_4$, filtration, sublimation
• C. Sublimation, addition of ${\mathrm{H}}_2\mathrm{O}$, filtration
• D. Evaporation, distillation, crystallization.

Answer 1

The correct option is B

Addition of ${\mathrm{CCl}}_4$, filtration, sublimation

Explanation for correct option:

(b) Addition of ${\mathrm{CCl}}_4$, filtration, sublimation

1. We are given a mixture of iodine, ammonium chloride and sand. We are asked to separate the components of this mixture.
2. Firstly, we add ${\mathrm{CCl}}_4$ to the mixture to dissolve iodine.
3. Secondly, we filter the mixture, sand and ammonium chloride will remain as residue and the iodine-tetrachloride solution will filter out.
4. Thirdly, we perform the sublimation of residue (sand and ammonium chloride).
5. Ammonium chloride sublimes and it will be deposited at the edges of the flask.

Explanation for incorrect options:

Since the correct order for separating the mixture of iodine, ammonium chloride and sand is addition of ${\mathrm{CCl}}_4$, filtration and sublimation thus option (a), (c) and (d) are incorrect.

Hence, option (b) is the correct option.