An excess of zinc powder is added to a fixed volume of dilute nitric acid of pH 4. The volume of hydrogen gas produced is measured over time.
The experiment is repeated using the same mass of excess zinc and the same volume of dilute nitric acid, but this time with a pH of 2.
State how many times greater the concentration of hydrogen ions is in the acid of pH 2 than in the acid of pH 4.
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.