Name the appropriate methods for the separation of the following :
(a) nitrogen from air (b) dye from blue ink (c ) cream from milk (d) ammonium chloride from common salt.

Explanation

(a) Nitrogen is one of the constituents of air. It can be separated with the help of fractional distillation.
(b) Chromatography helps in separating dye from blue ink.
(c ) Centrifugation or churning helps in separating cream from milk.
(d) Ammonium chloride is of volatile nature while common salt (sodium chloride) is not. The separation can be done with the help of sublimation.