Question

An aqueous solution has a mass of 490 grams containing 8.5 × 10-3 gram of calcium ions. The concentration of calcium ions in this solution is

Answer 1

The concentration may be expressed as % m/m, this is the mass of ions in 100 mass units of solution, whose formula is:

% m/m = [mass of ions / mass of solution]*100

Then,

%m/m = [8.5*10^ -3 grams of calcium ions] / [490 grams of solution] * 100 =

% m/m = 1.74 * 10^ -5 %

Answer: 1.74 * 10 ^ -5 %