Question

Question 23
You are provided with a mixture of naphthalene and ammonium chloride by your teacher. Suggest an activity to separate them with well labelled diagram.

Answer 1

The mixture of naphthalene and ammonium chloride can be separated by the process of sublimation. Naphthalene undergoes sublimation, i.e. it turns into vapours from a solid state without changing into a liquid state. Hence, leaving behind ammonium chloride. An activity to demonstrate this is given below:

Materials required - China dish, funnel, tripod, gas burner, cotton.
Process:
* Place the mixture in a china dish.
* Put it on the tripod.
* Cover the mixture with an inverted funnel.
* Put a cotton plug on the stem of the funnel.
* Now start heating the china dish slowly and observe.
Observation:
* You will observe that naphthalene gets deposited on the inner wall of the funnel because of sublimation leaving the ammonium chloride in the china dish.
* Scratch out the naphthalene deposited on the inner wall of the funnel.