A municipal water treatment facility processes brackish groundwater and surface runoff to produce potable water.
Brackish groundwater treatment:
Surface runoff treatment:
Which pair of concentrations represents the ion concentrations Z Z\,Z after the brackish groundwater undergoes reverse osmosis?
Ca2+:0.05 mol/dm3\text{Ca}^{2+} : 0.05\text{ mol/dm}^3Ca2+:0.05 mol/dm3 and SO42−:0.05 mol/dm3\text{SO}_4^{2-} : 0.05\text{ mol/dm}^3SO42−:0.05 mol/dm3
Ca2+:0.05 mol/dm3\text{Ca}^{2+} : 0.05\text{ mol/dm}^3Ca2+:0.05 mol/dm3 and SO42−:0.00 mol/dm3\text{SO}_4^{2-} : 0.00\text{ mol/dm}^3SO42−:0.00 mol/dm3
Ca2+:0.00 mol/dm3\text{Ca}^{2+} : 0.00\text{ mol/dm}^3Ca2+:0.00 mol/dm3 and SO42−:0.05 mol/dm3\text{SO}_4^{2-} : 0.05\text{ mol/dm}^3SO42−:0.05 mol/dm3
Ca2+:0.00 mol/dm3\text{Ca}^{2+} : 0.00\text{ mol/dm}^3Ca2+:0.00 mol/dm3 and SO42−:0.00 mol/dm3\text{SO}_4^{2-} : 0.00\text{ mol/dm}^3SO42−:0.00 mol/dm3
11 exam-style questions on AQA GCSE Chemistry 10.1 Using the Earth's resources and obtaining potable water, covering 10.1.1 Using the Earth's resources and sustainable development, 10.1.2 Potable water, 10.1.3 Waste water treatment, and 10.1.4 Alternative methods of extracting metals (HT only). Each one has a worked solution and a mark scheme showing where the marks go.