What is the volume of water required to prepare 200 mL of a 0.5 M solution using 4 g of NaOH (molar mass = 40 g/mol)?
Moles of NaOH = (4/40) = 0.1 mol . Molarity = (Moles/Volume in L) , so 0.5 = (0.1/V) . Volume = (0.1/0.5) = 0.2 L = 200 mL . Since total volume is 200 mL, water volume = 200 mL (assuming solute volume is negligible).
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Vapour Pressure and Raoult's Law - Ideal and Non-ideal Solutions