A solution is prepared by dissolving 2.00 g of NaCl in 500.0 mL of water at 298 K. What is the molarity of the solution?

easy 2 marks Class 12 · Chemistry · Solutions

Answer

0.068 M

The correct answer is 0.068 M — Compute molarity: $M = \frac{n}{V} = \frac{0.0342}{0.500} = 0.0684 mol L^{- 1} \approx 0.068 M$ .

Step-by-step solution

Calculate the moles of NaCl: $n = \frac{2.00 g}{58.44 g mol ^{- 1}} = 0.0342 mol$ .
Convert the volume of the solution to litres: $V = 500.0 mL = 0.500 L$ .
Compute molarity: $M = \frac{n}{V} = \frac{0.0342}{0.500} = 0.0684 mol L^{- 1} \approx 0.068 M$ .

Common mistake: Using mass of water instead of solution volume in litres

Concept tested: Molarity calculation

Published 5 September 2026 · Last updated 16 September 2026 · How this solution was prepared and checked