A Levels Chemistry

The amount of calcium ions in a sample of natural water can be determined by using an ion-
exchange column as shown in the diagram.
- water sample
-ion-exchange resin
A 50 cm³ sample of water containing dissolved calcium sulphate was passed through the ion-
exchange resin. Each calcium ion in the sample was exchanged for two hydrogen ions. The
resulting acidic solution collected in the flask required 25 cm³ of 1.0 x 10-² mol dm³ potassium
hydroxide for complete neutralisation.
What was the concentration of the calcium sulphate in the original sample?
A 2.5 x 10 moldm-3
B
1.0 x 102 moldm-3
C 2.0 x 102 moldm-3
D 4.0 x 102 moldm-3


Atoms, Molecules & Stoichiometry | 2006 - O/N - 9701/1 | Q1