Question

A 50cm3 sample of water containing dissolved CaSO4 was passed through ion-exchange resin. Each calcium in the sample was exchanged for two H+ ions, the resulting acidic solution collected in the flask required 25cm3 of 1*10^-3 mol/dm3 KOH for complete neutralization.what was the concentration of clacium sulphate in the original sample?

Answer 1

The concentration of calcium sulphate in the original sample can be calculated using the formula:

Concentration of CaSO4 = (Volume of KOH x Molarity of KOH x number of moles of H+) / Volume of the sample

Therefore, the concentration of calcium sulphate in the original sample = (25 x 0.001 x 2) / 50 = 0.005 mol/dm3.