0620_s23_qp_41
A paper of Chemistry, 0620
Questions:
7
Year:
2023
Paper:
4
Variant:
1

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Some symbol equations and word equations, A to J, are shown. A Fe3+ + 3OH– → Fe(OH)3 B H+ + OH– → H2O C ethane + chlorine → chloroethane + hydrogen chloride D C12H26 → C8H18 + C4H8 E ethene + steam → ethanol F chlorine + aqueous potassium iodide → iodine + aqueous potassium chloride G C6H12O6 → 2C2H5OH + 2CO2 H ethanoic acid + ethanol → ethyl ethanoate + water I calcium carbonate → calcium oxide + carbon dioxide J 6CO2 + 6H2O → C6H12O6 + 6O2 Use the equations to answer the questions that follow. Each equation may be used once, more than once, or not at all. Give the letter, A to J, for the equation that represents: a neutralisation reaction ������������������������������������������������������������������������������������������������������ a precipitation reaction �������������������������������������������������������������������������������������������������������� the formation of an ester ������������������������������������������������������������������������������������������������������ photosynthesis ��������������������������������������������������������������������������������������������������������������������� fermentation ������������������������������������������������������������������������������������������������������������������������� cracking. ������������������������������������������������������������������������������������������������������������������������������ 
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The symbols of the elements in Period2 of the Periodic Table are shown. Li Be B C N O F Ne Use the symbols of the elements in Period 2 to answer the questions that follow. Each symbol may be used once, more than once or not at all. Give the symbol of the element that: makes up approximately 78% of clean, dry air ������������������������������������������������������������� contains atoms with only three electrons in the outer shell ������������������������������������������ contains atoms with only nine protons �������������������������������������������������������������������������� exists as graphite ���������������������������������������������������������������������������������������������������������� is an alkali metal ����������������������������������������������������������������������������������������������������������� only has an oxidation number of zero. ������������������������������������������������������������������������� Boron, B, has two isotopes. State the meaning of the term isotopes. Table2.1 shows the relative masses and the percentage abundances of the two isotopes of boron. Table 2.1 relative mass of isotope percentage abundance of isotope Calculate the relative atomic mass of boron to one decimal place.  relative atomic mass = 
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Oxygen is produced by the decomposition of aqueous hydrogenperoxide. Manganese(oxide, MnO2, is a catalyst for this reaction. State the meaning of the term catalyst. A student adds powdered manganese(oxide to aqueous hydrogenperoxide in a conical flask as shown in Fig.4.1. The mass of the conical flask and its contents is measured at regular time intervals. The mass decreases as time increases. loosely fitting cotton wool plug aqueous hydrogen peroxide powdered manganese(oxide balance State why the mass of the conical flask and its contents decreases as time increases. The rate of reaction is highest at the start of the reaction. The rate decreases and eventually becomes zero. Explain why the rate of reaction is highest at the start of the reaction. Explain why the rate of reaction eventually becomes zero. The experiment is repeated at an increased temperature. All other conditions stay the same. Explain in terms of collision theory why the rate of reaction is higher at an increased temperature. The equation for the decomposition of aqueous hydrogenperoxide, H2O2, is shown. 2H2O2→ 2H2O+ O250.0 cm3 of a 0.200 mol / dm3 solution of H2O2is used. Calculate the mass of O2 that forms. Use the following steps. ● Calculate the number of moles of H2O2 used.  mol ● Determine the number of moles of O2 produced.  mol ● Calculate the mass of O2 produced.  g  State the effect on the mass of oxygen produced if the mass of powdered manganese(oxide catalyst is increased. Oxygen can also be produced by the decomposition of mercury(oxide, HgO. The only products of this decomposition are mercury and oxygen. Write a symbol equation for this decomposition. 
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This question is about sulfur and compounds of sulfur. Sulfur is converted into sulfuricacid, H2SO4, by the Contact process. The process involves four stages. stage 1 Molten sulfur is converted into sulfur dioxide. stage 2 Sulfur dioxide reacts with oxygen to form sulfur trioxide. stage 3 Sulfur trioxide combines with concentrated sulfuric acid to form oleum, H2S2O7. stage 4 Oleum reacts to form concentrated sulfuric acid. In stage 1, iron pyrites, FeS2, can be used instead of molten sulfur. The iron pyrites is heated strongly in air. Balance the equation for the reaction occurring when iron pyrites reacts with oxygen in the air. FeS2 + O2 → Fe2O3 + SO2 Name Fe2O3. Include the oxidation number of iron. The equation for stage 2 is shown. 2SO2+ O22SO3The forward reaction is exothermic. The reaction is carried out at a temperature of 450 °C and a pressure of 2 atm. Using explanations that do not involve cost: explain why a temperature greater than 450 °C is not used explain why a pressure lower than 2 atm is not used. When sulfuricacid reacts with ammonia the salt produced is ammoniumsulfate. Write the symbol equation for this reaction. Lead(sulfate is an insoluble salt. Lead(sulfate can be made from aqueous ammoniumsulfate using a precipitation reaction. Name a solution that can be added to aqueous ammoniumsulfate to produce a precipitate of lead(sulfate. Write an ionic equation for this precipitation reaction. Include state symbols. The precipitate of lead(sulfate forms in an aqueous solution. Describe how pure lead(sulfate can be obtained from the mixture. 
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