A sample of well water contains 140 gm/m3 Ca2+ ions and 345 gm/m3 Na+ ions. The hardness of the sample of water, expressed in terms of equivalent CaCO3 in gm/m3 is (assuming atomic masses of Ca :40, Na : 23, C : 12, O : 16) ?

Question

Accepted Answer

350. Hardness is calculated by converting the given ion concentrations to their CaCO3 equivalents. The total equivalent concentration is 140 + (345 * (100/23)) / 100 = 350 gm/m3.