Which of the two will scatter light: soap solution or salt solution?

Suggest a suitable separation technique for the following:
$(i)$ Mercury and water.
$(ii)$ Coloured components from blue ink.
$(iii)$ Ammonium chloride and potassium chloride.
$(iv)$ Mixture of alcohol and water.

When is a compound said to be pure?

Salt can be recovered from its solution by evaporation. Can you suggest any other technique also?

Give an example for each of the following:
$(a)$ Solid-liquid homogeneous mixture
$(b)$ Gas-gas homogeneous mixture
$(c)$ Solid-solid homogeneous mixture
$(d)$ Solid-liquid heterogeneous mixture
$(e)$ Liquid-liquid heterogeneous mixture

The substances that sublime can be made to liquefy by