A 150.0 g sample of ocean water contains 3.5 mg of mercury.How many parts per million of mercury are in the sample?

Question

Quizplus · Accepted Answer

First, we need to convert 3.5 mg to g, which is 0.0035 g. Then we can use the formula for parts per million (ppm):
ppm = (mass of substance / total mass) x 10^6
= (0.0035 g / 150.0 g) x 10^6
= 23.3 ppm
We round to the nearest whole number, so the answer is 23 ppm, which corresponds to choice (B).

A 1500 G Sample of Ocean Water Contains 3