AQA GCSE COMBINED SCIENCE: TRILOGY 8464/C/2H Chemistry Paper 2H Version: 1.0 Final *JUN238464C2H01* IB/M/Jun23/E7 8464/C/2H QUESTION PAPER & MARKING SCHEME/ [MERGED]

GCSE COMBINED SCIENCE: TRILOGY 8464/C/2H Chemistry Paper 2H Version: 1.0 Final *JUN238464C2H01* IB/M/Jun23/E7 8464/C/2H For Examiner’s Use Question Mark 1 2 3 4 5 6 TOTAL Tuesday 13 June 2023 Morning Time allowed: 1 hour 15 minutes Materials For this paper you must have: • a ruler • a scientific calculator • the periodic table (enclosed). Instructions • Use black ink or black ball-point pen. • Pencil should only be used for drawing. • Fill in the boxes at the top of this page. • Answer all questions in the spaces provided. • 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). • Do all rough work in this book. Cross through any work you do not want to be marked. • In all calculations, show clearly how you work out your answer. Information • The maximum mark for this paper is 70. • The marks for questions are shown in brackets. • You are expected to use a calculator where appropriate. • You are reminded of the need for good English and clear presentation in your answers. Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. GCSE COMBINED SCIENCE: TRILOGY Higher Tier Chemistry Paper 2H H 2 *02* IB/M/Jun23/8464/C/2H There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Do not write outside the box 3 *03* Turn over ► IB/M/Jun23/8464/C/2H Do not write outside the 0 1 box The combustion of fuels is a source of atmospheric pollutants. 0 1 . 1 Methane is a fuel. Balance the equation for the combustion of methane. [1 mark] CH4 + O2 → CO2 + H2O 0 1 . 2 Many fuels are mixtures. Petrol and diesel are mixtures of hydrocarbons. Table 1 shows properties of petrol and of diesel. Table 1 Petrol Diesel Range of number of carbon atoms in a hydrocarbon molecule 4 to 12 12 to 20 Range of boiling points in °C 40 to 205 250 to 350 Compare the properties of petrol and diesel. Use Table 1. [2 marks] Do not write outside the box 4 *04* IB/M/Jun23/8464/C/2H Do not write outside the 0 1 box . 3 The gases released when a fuel is burned in car engines may include: • oxides of nitrogen • carbon monoxide • water vapour. Which chemical element do all these gases contain? [1 mark] Tick () one box. Carbon Hydrogen Nitrogen Oxygen 0 1 . 4 When diesel burns in car engines, oxides of nitrogen are produced. Where does the nitrogen come from? [1 mark] 0 1 . 5 When diesel burns, particulates may be produced. What environmental effect do particulates from burning diesel cause? [1 mark] 5 *05* Turn over ► IB/M/Jun23/8464/C/2H Do not write outside the box 12 0 1 . 6 Carbon monoxide may be produced when diesel burns. Give one reason why carbon monoxide is difficult to detect. [1 mark] 0 1 . 7 Explain why water vapour and not liquid water is produced when diesel burns. [2 marks] 0 1 . 8 Sulfur is a common impurity in diesel. Explain why this causes an environmental problem. [3 marks] 6 *06* IB/M/Jun23/8464/C/2H Do not write outside the 0 2 Chromatography is used to separate mixtures. box Chromatography involves a mobile phase and one other phase. 0 2 . 1 What is the other phase in chromatography? [1 mark] Tick () one box. Moving phase Recycled phase Stationary phase Viscous phase 0 2 . 2 Why do the substances in the mixture separate in the mobile phase? [1 mark] 0 2 . 3 How many spots will be produced on the chromatogram of a pure compound? [1 mark] Number of spots = 7 *07* Turn over ► IB/M/Jun23/8464/C/2H Do not write outside the 0 2 box . 4 In a chromatography experiment, a blue colour moved 4.77 cm. The solvent moved 5.30 cm. Calculate the Rf value for the blue colour. [2 marks] Rf value = Question 2 continues on the next page 8 *08* IB/M/Jun23/8464/C/2H Do not write outside the box 11 0 2 . 5 Black ink is a mixture of several colours. Plan an experiment using paper chromatography to: • separate the colours in black ink • identify the colours from their Rf values. [6 marks] 9 *09* Turn over ► IB/M/Jun23/8464/C/2H Do not write outside the Turn over for the next question box DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED 10 *10* IB/M/Jun23/8464/C/2H Do not write outside the 0 3 Crude oil is a mixture of many different compounds. box 0 3 . 1 Give two reasons why crude oil is not a formulation. [2 marks] 1 2 0 3 . 2 Describe how crude oil is separated into fractions. [4 marks] 0 3 . 3 The fractions from crude oil contain alkanes. Explain why alkanes are cracked. [2 marks] 11 *11* Turn over ► IB/M/Jun23/8464/C/2H Do not write outside the box 11 Cracking produces a mixture of products. 0 3 . 4 An equation for cracking decane (C10H22) is: C10H22(l) → C10H20(l) + H2(g) Describe a test to identify the gas produced in the reaction. [2 marks] Test Result 0 3 . 5 Alkenes are produced in cracking. The general formula for the homologous series of alkenes is CnH2n Which formula represents an alkene? [1 mark] Tick () one box. C2H2 C2H4 C2H6 C3H8 Turn over for the next question 12 *12* IB/M/Jun23/8464/C/2H Do not write outside the 0 4 Some types of water contain dissolved substances. box A student investigated the mass of dissolved solids in distilled water and in sea water. Figure 1 shows the apparatus. Figure 1 This is the method used. 1. Weigh an evaporating basin. 2. Add 20 cm3 of distilled water to the evaporating basin. 3. Weigh the evaporating basin and the water sample. 4. Heat the water sample for 2 minutes. 5. Weigh the evaporating basin and contents. 6. Repeat steps 1 to 5 two more times. 7. Repeat steps 1 to 6 with sea water. 0 4 . 1 The method used by the student did not give valid results. Describe one improvement the student could make to obtain valid results. [1 mark] 13 *13* Turn over ► IB/M/Jun23/8464/C/2H Do not write outside the A different student used a method which gave valid results. box 0 4 . 2 Table 2 shows the results. Table 2 Mass of dissolved solids in grams Type of water Test 1 Test 2 Test 3 Mean Distilled water 0.00 0.00 0.00 0.00 Sea water 0.30 X 0.26 0.29 Calculate the value X for the mass of dissolved solids in sea water in Test 2. [2 marks] Mass X = g 0 4 . 3 The student concludes that distilled water is pure. Describe a test to confirm that distilled water is pure. [2 marks] Test Result 14 *14* IB/M/Jun23/8464/C/2H Do not write outside the Tap water is potable. box A stage in the production of potable water