Question

A 500 g toothpaste sample has 0.2 g fluoride concentration. What is the concentration of fluorine in terms of ppm level?

Options

• 250

• 200

• 400

• 1000

Answer 1

400

Explanation:

Given: Mass of fluoride (solute) = 0.2 g

Mass of toothpaste (sample/solution) = 500 g

We know that

ppm = `"mass of solute"/"mass of solution" xx 10^6`

ppm = `0.2/500 xx 10^6`

ppm = 400