Lesson eLearning

A 100 g sample of crude oil contains 98.5 g of pure hydrocarbons and 1.5 g of impurities. What is the purity percentage of the sample?

medium 3 marks Class 9 · Science · Is Matter Around Us Pure
Answer
98.5%

The correct answer is 98.5% — Purity % = (mass of pure substance / total mass) × 100 = (98.5/100)×100 = 98.5 %.

Step-by-step solution

  1. Total mass = 98.5 g + 1.5 g = 100 g.
  2. Purity % = (mass of pure substance / total mass) × 100 = (98.5/100)×100 = 98.5 %.
Common mistake: Using total mass incorrectly

Concept tested: Calculate purity

Published · How this solution was prepared and checked

← All Is Matter Around Us Pure questions