A student carries out a titration by adding sodium hydroxide solution from a burette into a conical flask containing dilute hydrochloric acid and a few drops of methyl orange indicator.
Which of the following shows the colour change that is seen in the conical flask at the end point of this titration?
yellow to red
red to yellow
colourless to pink
pink to colourless
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.