Skip to content

Lesson eLearning

A 100 g sample of refined table salt (NaCl) contains 5 g of impurities. Calculate the purity percentage of the salt.

easy 2 marks Class 9 · Science · Is Matter Around Us Pure

Answer

95%

The correct answer is 95% — $\frac{95}{100} \times 100 = 95%$

Step-by-step solution

Compute the mass of pure salt: $100 - 5 = 95$  g.
Calculate purity percentage using $\frac{mass of pure}{total mass} \times 100$ .
$\frac{95}{100} \times 100 = 95%$

Common mistake: Adding impurities instead of subtracting

Concept tested: Purity calculation

Published 16 October 2026 · How this solution was prepared and checked

← All Is Matter Around Us Pure questions