Question

How would you separate the mixtures given in the Table? Mention the reason for choosing your method. If a mixture cannot be separated, explain why.

Mixture	Method of separation	Reason for selection
Mud from muddy water
Plasma from other components in the blood sample
Naphthalene and sand
Chalk powder and common salt
Common salt and water
Oil from water
Pigments of the flower

Answer 1

Mixture	Method of separation	Reason for selection
Mud from muddy water	Filtration	Mud particles are large enough to settle at the bottom and be retained by filter paper.
Plasma from other components in the blood sample	Centrifugation	Blood cells are denser than plasma, so spinning separates them according to their density.
Naphthalene and sand	Sublimation	When heated, naphthalene changes directly into vapour, while sand remains unchanged.
Chalk powder and common salt	Dissolution + Filtration	Salt is soluble in water, whereas chalk powder is insoluble and remains undissolved.
Common salt and water	Evaporation	As the water evaporates, the dissolved salt remains as a solid residue.
Oil from water	Separating funnel	Oil is less dense than water, causing it to float and form a separate layer.
Pigments of the flower	Chromatography	Pigments move at different rates because they differ in their solubility and attraction to the solvent.