Ead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0012 %Pb by mass. How much of the water (in mL) contains 150 mg of Pb? (Assume a density of 1.0)

1.3 × 10⁴ mL

Explanation:

A Pb-contaminated water sample contains 0.0012 %Pb by mass, that is, there are 0.0012 g of Pb in 100 g of solution. The mass of the sample that contains 150 mg (0.150 g) of Pb is:

0.150 g Pb × (100 g sample/0.0012 g Pb) = 1.25 × 10⁴ g sample

The density of the sample is 1.0 g/mL. The volume of the sample is:

1.25 × 10⁴ g × (1 mL/1.0 g) = 1.3 × 10⁴ mL