A solution contains 50 mg solute and the mass of solution is 2 kg. What is the ppm?
Answer and explanation
Correct answer: 25 ppm
For mass-based concentration, parts per million is calculated as ppm = (mass of solute ÷ mass of solution) × 1,000,000. Convert the solution mass to the same unit: 2 kg = 2,000,000 mg. Therefore, ppm = (50 ÷ 2,000,000) × 1,000,000 = 25 ppm. Option A is correct; using 2 instead of 2,000,000 would mix units and give an incorrect result.
Frequently asked questions
What is the correct answer to this question?
25 ppm
Why is this the correct answer?
For mass-based concentration, parts per million is calculated as ppm = (mass of solute ÷ mass of solution) × 1,000,000. Convert the solution mass to the same unit: 2 kg = 2,000,000 mg. Therefore, ppm = (50 ÷ 2,000,000) × 1,000,000 = 25 ppm. Option A is correct; using 2 instead of 2,000,000 would mix units and give an incorrect result.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Some Basic Concepts of Chemistry. Topic: Mole concept and molar mass.
