AQA A-level CHEMISTRY 7405/3 Paper 3 Version: 1.0 Final *JUN*QUESTION PAPER & MARKING SCHEME/ [MERGED] Mark scheme June 2023

AQA A-level CHEMISTRY 7405/3 Paper 3 Version: 1.0 Final *JUN* IB/M/Jun23/E9 7405/3 For Examiner’s Use Question Mark 1 2 3 4 5 6 Section B TOTAL Friday 23 June 2023 Morning Time allowed: 2 hours Materials For this paper you must have: • the Periodic Table/Data Booklet, provided as an insert (enclosed) • a ruler with millimetre measurements • a scientific calculator, which you are expected to use where appropriate. Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the top of this page. • Answer all questions. • You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s). • All working must be shown. • Do all rough work in this book. Cross through any work you do not want to be marked. Information • The marks for questions are shown in brackets. • The maximum mark for this paper is 90. Advice • You are advised to spend 70 minutes on Section A and 50 minutes on Section B. Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. A-level CHEMISTRY Paper 3 2 *02* IB/M/Jun23/7405/3 Do not write outside the Section A box Answer all questions in this section. 0 1 Ethyl ethanoate can be made by reacting ethanol with ethanoic acid in the presence of concentrated sulfuric acid. Method 1. A mixture of ethanol, ethanoic acid, and concentrated sulfuric acid, with anti-bumping granules, is heated under reflux for 10 minutes. 2. The apparatus is rearranged for distillation. 3. The mixture is heated to collect the liquid that distils between 70 and 85 °C 4. The distillate is placed in a separating funnel. Aqueous sodium carbonate is added, and a stopper is placed in the funnel. The mixture is shaken, releasing pressure as necessary. 5. The lower aqueous layer is removed and the upper organic layer is placed in a small conical flask. 6. Anhydrous calcium chloride is added to the sample in the conical flask. The flask is shaken well and left for a few minutes. 7. The liquid from the flask is redistilled and the distillate is collected between 74 and 79 °C 0 1 . 1 State the role of concentrated sulfuric acid in this reaction. [1 mark] 0 1 . 2 The reaction mixture is flammable. Suggest how the reaction mixture should be heated in step 1. [1 mark] 3 *03* Turn over ► IB/M/Jun23/7405/3 Do not write outside the 0 1 box . 3 Figure 1 shows how a student set up the apparatus for reflux in step 1. You should assume that the apparatus is clamped correctly. Figure 1 Identify two mistakes the student made in setting up the apparatus. State the problem caused by each mistake. [4 marks] Mistake 1 Problem caused Mistake 2 Problem caused 4 *04* IB/M/Jun23/7405/3 Do not write outside the 0 1 box . 4 State why sodium carbonate is added to the distillate in step 4. Explain why there is a build-up of pressure in the separating funnel. [2 marks] 0 1 . 5 Give a reason why two layers form in the separating funnel. Suggest why ethyl ethanoate forms the upper layer. [2 marks] Reason Suggestion 0 1 . 6 State why anhydrous calcium chloride is added in step 6. [1 mark] 5 *05* Turn over ► IB/M/Jun23/7405/3 Do not write outside the 0 1 box . 7 A student uses the method to prepare some ethyl