common ion effect is the exchange of one electrolyte with another electrolyte having a common ion. In the purification of solid sodium chloride using the apparatus that are, stand, round bottom flask, funnel, rubber tube, delivery tube, burner, the beaker and cork.

The chemicals that are used through the purification of sodium chloride are, hydrochloric acid and sulfuric acid. First of all, take the solid sodium chloride in a round bottom flask then take the saturated solution of sodium chloride in another beaker and hydrochloric acid gas passed into it.

During this process is the chemical reaction takes place, in which two molecules of solid sodium chloride react with sulfuric acid to form sodium sulphate and hydrochloric acid.

By doing this reaction, crystals of sodium chloride will formed and after this washed these crystals by distilled water and dried through filter paper. It must be noted that, the hydrochloric acid gas passed through the solution in excess.

Apparatus must be fully tight & air can not pass through it. Use clean and dry apparatus. For practical the apparatus should be washed through distilled water. By common ion effect we can also take purification of others salts like potassium chloride, iron and sulfur.