What is the mole fraction of acetone (molar mass = 58 g/mol) in a solution containing 29 g of acetone and 54 g of water?
Moles of acetone = (29/58) = 0.5 mol . Moles of water = (54/18) = 3 mol . Total moles = 0.5 + 3 = 3.5 . Mole fraction = (0.5/3.5) ≈ 0.143 .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Abnormal Molar Masses and van't Hoff Factor