An industrial chemist is investigating the effectiveness of different forms of calcium carbonate in neutralizing acidic wastewater from a manufacturing plant.
They use the following method:
Step 1: Transfer 50 cm3 of the acidic wastewater into two separate conical flasks, labelled P and Q.
Step 2: Measure the initial pH of the wastewater in both flasks.
Step 3: Add 1.5 g of calcium carbonate powder to flask P.
Step 4: Add 1.5 g of calcium carbonate chips to flask Q.
Step 5: Stir both flasks for 5 minutes and then measure the final pH of each mixture.
State one piece of equipment the chemist could use to measure the pH of the wastewater.
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.