OCR 2023 GCSE CHEMISTRY B TWENTY FIRST CENTURY SCIENCE J258/01: BREADTH IN CHEMISTRY (FOUNDATION TIER) QUESTION PAPER & MARK SCHEME (MERGED)

2 © OCR 2023 1 The increase in global population means there is a greater need for drinking water. (a) What is the correct term for drinking water? Tick () one box. Ground water Potable water Sea water Waste water [1] (b) One source of drinking water is salt water. Describe a process that separates water from salt water. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...........................................................................................................................................[2] (c) Chlorine is added to drinking water. (i) Why is chlorine added? ........................................................................................................................................... . ..................................................................................................................................[1] (ii) Suggest one disadvantage of adding chlorine to drinking water. ........................................................................................................................................... . ..................................................................................................................................[1] 13 © OCR 2023 Turn over It gives a ‘pop’ with a lighted splint. Oxygen It turns limewater milky. (iii) Chlorine and other gases can be identified by simple tests. Draw lines to connect each gas with its correct test. [3] It turns b