An environmental scientist treats a sample of acidic run-off containing dilute nitric acid by gradually adding solid calcium hydroxide, Ca(OH)2\text{Ca(OH)}_2Ca(OH)2. During this treatment, the pH of the run-off is observed to rise.
Explain, in terms of the reacting particles, why the addition of calcium hydroxide causes the pH of the solution to increase.
276 exam-style questions on Edexcel GCSE Chemistry 4.1 Acids, covering 4.1.1 Acids, alkalis and the pH scale, 4.1.2 Hydrogen ion concentration and pH, 4.1.3 Dilute and concentrated, weak and strong acids, 4.1.4 Bases, alkalis and the reactions of acids, 4.1.5 Chemical tests for hydrogen and carbon dioxide, 4.1.6 Neutralisation as a reaction of acids with bases, 4.1.7 Preparing soluble salts, and 4.1.8 Solubility rules and preparing insoluble salts. Each one has a worked solution and a mark scheme showing where the marks go.