During the electrolysis of acidified water, a gas is collected at the negative electrode (cathode).
What is the correct and safe way to test this gas to confirm that it is hydrogen?
Hold a piece of damp blue litmus paper near the mouth of the test tube.
Place a lighted splint at the open mouth of the test tube.
Place a glowing splint inside the test tube.
Bubble the gas through a beaker of limewater.
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.