An aqueous solution has a mass of 490 grams

containing 8.5 103 gram of calcium ions. The

concentration of calcium ions in this solution is

(1) 4.3 ppm (3) 17 ppm

(2) 8.5 ppm (4) 34 ppm

One way of expressing concentration is by expressing it by parts per million or ppm. Parts per million is equal to 1 milligram of solute per kilogram of solution. The problem is solved as follows:

ppm =.0085103 mg /.490 kg = 0.017 ppm