What is the mass of water needed to prepare 150 g of a 20% by mass sugar solution?
Mass of sugar = (20/100) × 150 = 30 g . Mass of water = 150 - 30 = 120 g .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Solubility - of Solids and Gases in Liquids Henry's Law