OCR AS Level Chemistry A H032/02 Depth in chemistry JUNE 2022

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AS Level Chemistry A H032/02 Depth in chemistry JUNE 2022 Time allowed: 1 hour 30 minutes INSTRUCTIONS • Use black ink. You can use an HB p... encil, but only for graphs and diagrams. • Write your answer to each question in the space provided. If you need extra space use the lined pages at the end of this booklet. The question numbers must be clearly shown. • Answer all the questions. • Where appropriate, your answer should be supported with working. Marks might be given for using a correct method, even if your answer is wrong. INFORMATION • The total mark for this paper is 70. • The marks for each question are shown in brackets [ ]. • Quality of extended response will be assessed in questions marked with an asterisk (*). • This document has 16 pages. ADVICE • Read each question carefully before you start your answer. © OCR 2022 [601/5256/4] DC (ST/CT) 300581/3 OCR is an exempt Charity Turn over Answer all the questions. 1 Lime is a citrus fruit containing citric acid, C6H8O7. (a) Citric acid is a weak organic acid. (i) What is meant by an acid? ...................................................................................................................................... [1] (ii) What is meant by an acid that is weak? ........................................................................................................................................... ...................................................................................................................................... [1] (b) A student carries out a titration to determine the mass of citric acid in a lime. The student follows the method below: • Squeeze the juice out of two limes. • Transfer the juice into a 250.0 cm3 volumetric flask and make up to the mark with distilled water. • Pipette 25.0 cm3 of the diluted lime juice into a conical flask and add a few drops of phenolphthalein indicator. • Titrate this solution with 0.800 mol dm–3 NaOH(aq). The student carries out a trial titration, followed by three further titrations. The diagram shows the burette readings for the three further titrations. Each reading is measured to the nearest 0.05 cm3. Titration 1 Titration 2 Titration 3 Initial reading Final reading Initial reading Final reading Initial reading Final reading 0 27 0 27 0 27 1 28 1 28 1 28 2 29 2 29 2 29 [Show More]

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