A solution contains 15 ppm of benzene.The density of the solution is 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

PPM (parts per million) is defined as the mass of solute per volume of solution (in mg/L). Therefore, if a solution has 15 ppm of benzene, it means that there are 15 mg of benzene in 1 L of solution. The density of the solution is irrelevant to this calculation.

So, if we assume that the solution has a mass of 1 g (which is the most common assumption), then 1.0 g of the solution contains 15 × 10^-6 g (or 15 μg) of benzene. This is choice C.

A Solution Contains 15 Ppm of Benzene