Question

if you are given a solution of common salt in water. how would you confirm that it is a true solution ?

Answer 1

A true solution is a homogeneous solution the particles are invisible even under powerful microscopes. For example, sodium chloride in water is a true solution.
Also when the solution is left standing, there is no settling down of the solute, which proves that it is a true solution.
 If above criterias satisfied by the given solution of common salt and water,
 Then , we can consider the given solution as a "true solution."

Answer 2

Pure water is obtained by fractional distillation. It has only water molecules. By this we conclude purity of water.