Question

State how a ‘supersaturated’ solution differs from a ‘saturated solution’. State briefly how you would prepare a supersaturated solution using potassium chloride and water.

Answer 1

Super saturated solution contains more amount of solute than saturated solution in hot solution. On cooling, it gives out excess salt which separate out.

Preparation of supersaturated solution of potassium chloride in water: 
Take 100 g of water and add little by little of KCl salt and stir it, if it gets dissolved, add a little more and stir it. We find that 35 g of KCl can make the solution saturated at 20°C. Now heat the saturated solution and add more of KCl. At 40°C it will dissolve 40 g and 46 g at 60°C and 54 g at 80°C. This super saturated solution at 80°C. On cooling this super saturated solution excess of solute [KCl] crystals separates out.