Question

Name the appropriate methods for the separation of the following:

(a) Nitrogen from air

(b) Blue ink from dye

(c) Ammonium chloride from salt

Answer 1

(a) Nitrogen from air:

1. Distillation is the process of separating the components or substances present in a liquid mixture through selective boiling and condensation.
2. Distillation may result in complete or partial separation based on the difference in boiling points of the substances present in the liquid mixture.
3. Nitrogen has the lowest boiling point (-196 degree celsius) so it condenses and separates faster.

(b) Blue ink from dye :

1. Blue ink can be separated from a dye by chromatography.
2. We use chromatographic paper to separate out the components of a liquid mixture, which in this case is dye.
3. The reason this happens is that as the ink moves through the paper, the different dyes that are in it move at different speeds, which causes them to separate and become visible.
4. The blue ink from the dye can be separated by chromatography.

(c) Ammonium chloride from salt:

1. Salt and ammonium chloride can be separated using another process called sublimation.
2. Ammonium chloride directly becomes a gas from a solid on heating.
3. So when the mixture is heated, ammonium chloride would directly convert to a gas which can be captured.
4. Salt will be left behind as a solid as salt doesn't undergo sublimation.