A solution contains 25 g of a solute in 75 g of water. If the mass percentage of the solute is reduced to 20% by adding
Initial mass % = (25/25 + 75) × 100 = 25% . New mass % = 20% = (25/25 + 75 + w) × 100 . 0.2 (100 + w) = 25 , 100 + w = 125 , w = 25 g . Total mass = 100 + 25 = 125 g .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Solubility - of Solids and Gases in Liquids Henry's Law