A solution contains 15 ppm of benzene. The density of the solution is 1.00 g/mL. This means that ________. A)there are 15 mg of benzene in 1.0 g of this solution B)100 g of the solution contains 15 g of benzene C)1.0 g of the solution contains 15 × 10^-6 g of benzene D)1.0 L of the solution contains 15 g of benzene E)the solution is 15% by mass of benzene

Question

Quizplus · Accepted Answer

Parts per million (ppm) is a mass/volume measurement. Therefore, 15 ppm means 15 mg of benzene in 1 L of solution. Since the density of the solution is 1.00 g/mL, 1 L of the solution has a mass of 1000 g. Thus, 15 ppm of benzene in 1 L of solution is equivalent to 15 × 10^-6 g/mL * 1000 mL/L = 15 × 10^-3 g = 15 mg. Therefore, 1.0 g of the solution contains 15 × 10^-6 g/mL * 1.0 g/mL = 15 × 10^-6 g = 15 ppb of benzene. Therefore, choice C is the correct answer.

A Solution Contains 15 Ppm of Benzene