How do I separate iodine from sodium chloride?

1 Answer
Jul 12, 2016

Use the technique of sublimation.


When iodine is heated gently, it undergoes sublimation, that is, it changes directly from a solid to a vapour.

When the vapour hits a cold surface, it undergoes deposition, that is, changes from a gas back to a solid.

Here's your experiment.

Place mixture in an evaporating dish on a tripod in the fume hood.

Invert a funnel over the evaporating dish.

Use a burner to heat the dish slowly.

Purple iodine vapour will form, and solid iodine crystals will deposit inside the funnel.

The sodium chloride will remain in the bottom of the dish.