Which of the following techniques used for separation of those solutes that dissolve in the same solvent?

Chromatography

The correct answer is option 2. Chromatography

Chromatography is the technique used for separation of those solutes that dissolve in the same solvent.

For example: The ink that we use has water as the solvent and the dye is soluble in it.

As the water rises on the filter paper it takes along with it the dye particles.

Usually, a dye is a mixture of two or more colours.

The coloured component that is more soluble in water, rises faster and in this way the colours get separated.