OCR Oxford Camtyidge and RSA Friday 27 May 2022 - Morning GCSE (9—1) Chemistry A (Gateway Science) J248/03 Paper 3 (Higher Tier) Time allowed: 1 hour 45 minutes

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INSTRUCTIONS • Use black ink. You can use an HB pencil, but only for graphs and diagrams. • Write your answer to each question in the space provided. If you need extra space use the lined page... s 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 the answer is wrong. INFORMATION • The total mark for this paper is 90. • 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 24 pages. ADVICE • Read each question carefully before you start your answer. © OCR 2022 [601/8663/X] DC (ST/JG) 320594/5 R 2 © OCR 2022 SECTION A Answer all the questions. You should spend a maximum of 30 minutes on this section. Write your answer to each question in the box provided. 1 Which particle model diagram shows evaporation? A B C D Your answer [1] 2 The radius of a helium atom is 0.14nm. What is the radius of a helium atom in metres? A 0.14 × 10–10m B 1.4 × 10–10m C 1.4 × 10–9m D 14 × 10–9m Your answer [1] 3 © OCR 2022 Turn over 3 A Group 1 element reacts with a Group 7 element, so that both elements have a full outer shell of electrons. The table shows what happens to both elements during the reaction. Group 1 element Group 7 element A gains 1 electron loses 1 electron B gains 2 electrons loses 2 electrons C loses 1 electron gains 1 electron D loses 2 electrons gains 2 electrons Which row is correct? Your answer [1] 4 The diagram of an atom shows that electrons occupy shells around the nucleus. Which scientist proposed this atomic model? A Bohr B Dalton C J. J. Thomson D Mendeleev Your answer [1] 4 © OCR 2022 5 What is an oxidising agent? A A species that causes oxidation but does not get oxidised or reduced itself. B A species that is oxidised and reduced. C A species that is oxidised, while another species in the reaction is reduced. D A species that is reduced, while another species in the reaction is oxidised. Your answer [1] 6 Which statement about carbon allotropes is correct? A Buckminsterfullerene is a type of carbon nanotube. B Carbon atoms in diamond and graphite form 4 covalent bonds. C Graphene and graphite both have carbon atoms arranged in layers. D Strong covalent bonds cause diamond to have a high melting point. Your answer [1] 7 A student wants to separate substances by filtration. They write a method for the experiment but not in the correct order as shown. 1. Pour the mixture through the funnel into the conical flask. 2. Fold the filter paper. 3. Collect the filtrate in the conical flask. 4. Put the filter paper into the funnel. 5. Collect any insoluble substances on the filter paper. What is the correct method order for this experiment? A 1, 2, 4, 5, 3 B 2, 1, 4, 5, 3 C 2, 4, 1, 5, 3 D 4, 2, 5, 3, 1 Your answer [1] 5 © OCR 2022 Turn over 8 Molten sodium chloride can be electrolysed. What is the correct half equation for the reaction at the negative electrode (cathode)? A 2Cl – – 2e– Cl 2 B 2H+ + 2e– H2 C Na+ + e– Na D 4OH– – e– O2 + 2H2O Your answer [1] 9 One mole of hydrogen gas, H2, fills a volume of 24dm3. How much volume does 2.0g of hydrogen gas fill? A 12dm3 B 24dm3 C 36dm3 D 48dm3 Your answer [1] 10 Why do some polymers have different flexibilities? A They are more flexible because they contain covalent bonds. B They are more flexible as they do not have strong cross-links. C They are more rigid because they contain ionic bonds. D They are more rigid because they have weak intermolecular forces. Your answer [1] 6 © OCR 2022 11 A student investigates an endothermic reaction. Their results are shown in the table. Temperature Bond energies A increases less energy is needed to break bonds in reactants than is needed to make bonds in products B increases more energy is needed to break bonds in reactants than is needed to make bonds in products C decreases less energy is needed to break bonds in reactants than is needed to make bonds in products D decreases more energy is needed to break bonds in reactants than is needed to make bonds in products Which statement is correct for an endothermic reaction? Your answer [1] 12 A scientist investigates the melting point of some substances that may contain paracetamol as shown in the table. The melting point of pure paracetamol is 169°C. Substance Melting point (°C) 1 169 2 156 3 166 – 169 4 170 – 174 Which statement about the results is correct? A All of the substances contain paracetamol. B Substance 2 does not contain paracetamol. C Substance 3 is pure paracetamol. D Substance 4 is impure paracetamol. Your answer [1] 7 © OCR 2022 Turn over 13 A sample of propanoic acid, C3H6O2, is made using an isotope of hydrogen, called deuterium. The relative atomic mass of deuterium is 2.0. What is the relative molecular mass, Mr , of propanoic acid when deuterium atoms replace all the hydrogen atoms? A 68.0 B 74.0 C 80.0 D 86.0 Your answer [1] 14 Which statement about the bonding in magnesium oxide is correct? A There are strong covalent bonds between atoms. B There are strong cova [Show More]

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