In an environmental study of a freshwater ecosystem, a limnologist measures the pH of a lake. At the beginning of the year, the water has a pH of 6.0. Following runoff from a nearby industrial site, the pH of the lake water drops to 2.0.
State how many times greater the concentration of hydrogen ions is in the lake water of pH 2.0 than in the lake water of pH 6.0.
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.