Energetics: Edexcel International GCSE Chemistry questions

Every Edexcel International GCSE Chemistry exam question on Energetics (specification points 3.1–3.8), 2019–2025, with its mark scheme and examiner’s report.

All 176 questions on Energetics, as a list

June 2025, Paper 1, Q7(b) (2 marks): This is the student’s method. add 50 cm3 of sodium hydroxide solution to a glass beaker Step 1 Step 2 record the initial temperature of the sodium hydroxide sol
June 2025, Paper 1, Q7(c)(i) (1 mark): Plot the results on the grid. (1)
June 2025, Paper 1, Q7(c)(ii) (1 mark): Draw a circle around the anomalous result. (1)
June 2025, Paper 1, Q7(c)(iii) (2 marks): Draw a straight line of best fit through the first six points, ignoring the anomalous result. Draw another straight line of best fit through the last three poin
June 2025, Paper 1, Q7(d) (2 marks): The point where the lines cross shows the volume of acid needed to exactly neutralise the alkali and the maximum temperature reached. Use your graph to determin
June 2025, Paper 1, Q7(e) (2 marks): Explain what might have caused the anomalous result. (2)
June 2025, Paper 1, Q10(a) (4 marks): This is the student’s method. • pour some water into the copper can • record the mass of the spirit burner and fuel • measure the initial temperature of the wat
June 2025, Paper 1, Q10(b)(i) (2 marks): Calculate the value of heat energy change (Q) in joules. [for water, c = 4.2 J/g/°C 1.0 cm3 of water has mass = 1.0 g] (2) Q = J
June 2025, Paper 1, Q10(b)(ii) (5 marks): Calculate the enthalpy change (ΔH) in kJ/mol. [for ethanol, Mr = 46] Include a sign in your answer. (5) ΔH = kJ/mol
June 2025, Paper 2, Q2(a) (1 mark): State what is meant by the term exothermic. (1)
June 2025, Paper 2, Q2(e) (5 marks): Draw a reaction profile diagram for the reaction, showing ΔH and activation energy. Label the reactants and products. (5) Energy
June 2025 (R), Paper 1, Q10(a)(i) (2 marks): Explain an improvement to step 1 to produce a more accurate temperature rise. (2)
June 2025 (R), Paper 1, Q10(a)(ii) (1 mark): Give a reason why the student does not need to know the exact mass of zinc powder added in step 3. (1)
June 2025 (R), Paper 1, Q10(b)(i) (3 marks): The table shows the student’s results. volume of copper(II) sulfate solution in cm3 25.0 initial temperature of the copper(II) sulfate solution in °C 18.5 final
June 2025 (R), Paper 1, Q10(b)(ii) (4 marks): The student repeats the experiment and calculates Q as 3800 J. The solution used contains 6.38 g of copper(II) sulfate. Calculate the molar enthalpy change, ΔH,
June 2025 (R), Paper 2, Q7(b)(i) (3 marks): Use the bond energies to show that the molar enthalpy change, ΔH , is about −1300 kJ / mol. (3)
June 2025 (R), Paper 2, Q7(b)(ii) (3 marks): Complete the energy level diagram for the reaction between C2H5OH and O2 (3) energy
June 2025 (R), Paper 2, Q7(b)(iii) (2 marks): Explain, in terms of bonds broken and bonds made, why this reaction is exothermic. (2)
November 2024, Paper 1, Q9(a) (1 mark): Give a reason why the student uses an aluminium can rather than a glass beaker. (1)
November 2024, Paper 1, Q9(c)(i) (2 marks): Show that the heat energy needed to raise the temperature of 100 g of water by 50 °C is approximately 20 000 J. [for water, c = 4.2 J/g/°C] (2)
November 2024, Paper 1, Q9(c)(ii) (4 marks): The student burns 1.84 g of ethanol. Calculate the molar enthalpy change, ΔH, in kJ/mol, for the combustion of ethanol. Include a sign in your answer. [for etha
November 2024, Paper 2, Q6(b)(iii) (3 marks): Ethene reacts with bromine. The equation shows the displayed formulae of the reactants and product. H H H H Br → C C H C C + Br H H H Br Br The table shows some
November 2024, Paper 2, Q6(b)(iv) (2 marks): Explain why the reaction between ethene and bromine is exothermic. Refer to bond energies in your answer. (2)
June 2024, Paper 1, Q2(b)(i) (1 mark): State what is meant by the term exothermic. (1)
June 2024, Paper 1, Q10(b) (2 marks): The thermometer shows the highest temperature reached. 35 °C 30 Complete the table by giving the temperatures to the nearest 0.1°C (2) starting temperature of t
June 2024, Paper 1, Q10(c)(i) (2 marks): Show that the heat energy change (Q) for this reaction is about 2800 J. [for 1.0 cm3 of solution, mass = 1.0 g] [for the solution, c = 4.2 J/g/°C] (2)
June 2024, Paper 1, Q10(c)(ii) (4 marks): The mass of magnesium used by the student was 0.12 g. Calculate the value of the enthalpy change (ΔH), in kJ/mol, for the magnesium reacting with nitric acid. G
June 2024, Paper 1, Q10(d) (2 marks): Explain why using a polystyrene cup, instead of a glass beaker, would give a more accurate result. (2)
June 2024, Paper 2, Q7(c)(i) (3 marks): Calculate the enthalpy change (ΔH), in kJ/mol, for the reaction. Include a sign in your answer. (3) ΔH = kJ/mol
June 2024, Paper 2, Q7(c)(ii) (4 marks): Draw a reaction profile for the reaction. Label the reactants, the products, ΔH and the activation energy (Ea). (4) energy
June 2024 (R), Paper 1, Q6(b)(i) (2 marks): In one experiment, the student uses liquid ethanol as the fuel. The thermometer shows the temperature of the water at the start of the experiment. ºC 23 22 21 2
June 2024 (R), Paper 1, Q6(b)(ii) (2 marks): The metal can contains water of mass 150 g. Show, by calculation, that the heat energy change (Q) for this reaction is approximately 36 000 J. [for water, c = 4
June 2024 (R), Paper 1, Q6(b)(iii) (4 marks): In the experiment, 2.3 g of ethanol (Mr = 46) is burned. Calculate the molar enthalpy change (ΔH), in kJ/mol, for the combustion of ethanol, C2H5OH Include a si
June 2024 (R), Paper 1, Q6(c) (1 mark): In this experiment, the calculated value of ΔH is less than the value given in a data book. Give a possible reason for the difference in values. (1)
June 2024 (R), Paper 2, Q1(b)(i) (1 mark): Give a reason why the mixture of sulfur and zinc needs heating before a reaction occurs. (1)
June 2024 (R), Paper 2, Q7(b)(i) (3 marks): Using the data in the table and the equation, show that the enthalpy change, ΔH , is approximately –40 kJ / mol. (3)
June 2024 (R), Paper 2, Q7(b)(ii) (2 marks): Explain, in terms of bonds broken and bonds made, why this reaction is exothermic. (2)
June 2024 (R), Paper 2, Q7(b)(iii) (3 marks): Draw an energy level diagram for the reaction between ethene and steam. Label the enthalpy change, ΔH . (3) Energy
November 2023, Paper 2, Q4(a) (2 marks): State two factors that the student must keep constant to make this a valid investigation. (2) 1 2
November 2023, Paper 2, Q4(b) (2 marks): Explain how using a polystyrene cup, instead of a glass beaker, would increase the accuracy of the results. (2)
November 2023, Paper 2, Q4(c)(i) (1 mark): Use the graph to determine the maximum temperature change in °C. (1) maximum temperature change = °C
November 2023, Paper 2, Q4(c)(ii) (3 marks): Explain the shape of the graph. (3)
November 2023, Paper 2, Q4(d) (4 marks): The student repeats the experiment using a polystyrene cup. These are the student’s results. Maximum temperature change 35 °C 25 cm3 Volume of hydrochloric acid
November 2023, Paper 2, Q7(d)(i) (3 marks): Use the equation and the values in the table to calculate the enthalpy change, ΔH , for the reaction. Include a sign in your answer. (3) ΔH = kJ
November 2023, Paper 2, Q7(d)(ii) (3 marks): Complete the diagram to show the energy levels of the reactants and products, and the enthalpy change, ΔH . (3) Energy
June 2023, Paper 1, Q8(a)(i) (1 mark): State why the student stirs the water. (1)
June 2023, Paper 1, Q8(a)(ii) (1 mark): Suggest why it is important that the student immediately finds the final mass of the spirit burner and pentanol. (1)
June 2023, Paper 1, Q8(b) (2 marks): The diagram shows the initial temperature of the water. °C 20 15 Complete the table to show the temperature readings. Give both values to the nearest 0.1 °C. (2
June 2023, Paper 1, Q8(c)(i) (2 marks): Show by calculation that the heat energy (Q) supplied by the pentanol is approximately 15 000 J. [for water, c = 4.2 J / g / °C] [for 1.0 cm3 of water, mass = 1
June 2023, Paper 1, Q8(c)(ii) (5 marks): The table gives the initial and final mass readings. Initial mass of spirit burner and pentanol in g 90.11 Final mass of spirit burner and pentanol in g 89.75 U
June 2023, Paper 2, Q6(b)(i) (1 mark): State which two bonds need to be broken in the reactants. (1)
June 2023, Paper 2, Q6(b)(ii) (2 marks): Explain why the enthalpy change in this reaction is approximately 0 kJ / mol. (2)
June 2023 (R), Paper 1, Q11(a)(i) (1 mark): Plot the student’s results on the grid. (1)
June 2023 (R), Paper 1, Q11(a)(ii) (1 mark): Draw a circle around the anomalous result. (1)
June 2023 (R), Paper 1, Q11(a)(iii) (1 mark): Draw a curve of best fit. (1) 21 20 19 Temperature 18 in °C 17 16 15 0 1 2 3 4 5 6 7 8 Mass of sodium hydrogencarbonate in g
June 2023 (R), Paper 1, Q11(b)(i) (2 marks): Explain why using a polystyrene cup makes the results more accurate. (2)
June 2023 (R), Paper 1, Q11(b)(ii) (1 mark): Suggest a mistake the student might have made to cause the anomalous result. (1)
June 2023 (R), Paper 1, Q11(b)(iii) (1 mark): State how the results show the reaction is complete. (1)
June 2023 (R), Paper 1, Q11(b)(iv) (1 mark): State how the results show that the reaction is endothermic. (1)
June 2023 (R), Paper 1, Q11(c) (2 marks): Use the results to calculate the heat energy change, Q, in joules. [for 1.0 cm3 of ethanoic acid solution, mass = 1.0 g] [for ethanoic acid solution, c = 4.2 J
June 2023 (R), Paper 1, Q11(d) (4 marks): The student repeats the experiment starting with a different volume of ethanoic acid solution. The student uses 7.0 g of sodium hydrogencarbonate to neutralise
June 2023 (R), Paper 2, Q7(b)(i) (3 marks): Show that the molar enthalpy change, ΔH, for the reaction is −119 kJ / mol. (3)
June 2023 (R), Paper 2, Q7(b)(ii) (2 marks): Explain why this reaction is exothermic. (2)
January 2023, Paper 1, Q10(a) (1 mark): Name a suitable piece of apparatus to add 25 cm3 of solution to the beaker. (1)
January 2023, Paper 1, Q10(b)(i) (4 marks): Calculate the theoretical maximum temperature reached by the mixture, which has a mass of 50 g. [specific heat capacity of mixture, c = 4.2 J / g / °C] (4) temp
January 2023, Paper 1, Q10(b)(ii) (1 mark): Give a reason why the maximum temperature recorded by the student is lower than the theoretical maximum temperature calculated. (1)
January 2023, Paper 1, Q10(b)(iii) (3 marks): In the reaction, 0.0500 mol of hydrochloric acid completely react. Calculate the molar enthalpy change, ΔH , in kilojoules per mole of hydrochloric acid. Includ
January 2023, Paper 2, Q7(b)(i) (2 marks): Use the data in the table to calculate the total energy needed to break all the bonds in the reactants. (2) energy needed = kJ
January 2023, Paper 2, Q7(b)(ii) (2 marks): Use the data in the table to calculate the total energy released when all the bonds in the products are made. (2) energy released = kJ
January 2023, Paper 2, Q7(b)(iii) (1 mark): Calculate the enthalpy change, ΔH, in kJ/mol, for the reaction. (1) ΔH = kJ/mol
January 2023, Paper 2, Q7(b)(iv) (2 marks): Explain, in terms of bonds broken and bonds made, why this reaction is exothermic. (2)
January 2023 (R), Paper 1, Q7(b)(i) (1 mark): State what is meant by the term exothermic. (1)
January 2023 (R), Paper 1, Q10(a) (2 marks): Give two reasons why the student stirs the mixture. (2) 1 2
January 2023 (R), Paper 1, Q10(b) (2 marks): The diagram shows the minimum temperature of the solution. °C 20 15 Complete the table by giving the missing information. Give both values to the nearest 0.1 °C
January 2023 (R), Paper 1, Q10(c)(i) (2 marks): Show that the heat energy change, Q, in this experiment is about 800 J. [c = 4.2 J / g / °C for the solution] [mass = 1.0 g for 1.0 cm3 of solution] (2)
January 2023 (R), Paper 1, Q10(c)(ii) (4 marks): The student uses 2.8 g of ammonium nitrate in this experiment. Calculate the enthalpy change, ΔH, in kJ / mol. Include a sign in your answer. [for NH4NO3, Mr =
January 2023 (R), Paper 1, Q10(e) (2 marks): In another experiment the student adds anhydrous copper(II) sulfate to distilled water. The table shows the student’s results. initial temperature of water in °
January 2023 (R), Paper 2, Q3(a) (3 marks): Calculate the heat energy, in kJ/mol, produced by the fuel. You should assume that the fuel is pure carbon. Give your answer to three significant figures. [for
January 2023 (R), Paper 2, Q8(a) (4 marks): In a car engine, nitrogen reacts with oxygen to form nitrogen monoxide. The equation for the reaction is N2 + O2 → 2NO ΔH = +181 kJ Draw a labelled reaction pro
January 2023 (R), Paper 2, Q8(b)(i) (1 mark): Calculate the total amount of energy, in kJ, needed to break the bonds in the reactants. (1) energy needed = kJ
January 2023 (R), Paper 2, Q8(b)(ii) (1 mark): Calculate the total amount of energy, in kJ, released in forming the bonds in the product. (1) energy released = kJ
January 2023 (R), Paper 2, Q8(b)(iii) (2 marks): Calculate the enthalpy change, ΔH, for the reaction. You should include a sign in your answer. (2) ΔH = kJ
June 2022, Paper 2, Q7(b) (2 marks): In one experiment, the student burns 0.92 g of ethanol. The student calculates that the heat energy absorbed by the water is 18.2 kJ. Show that the results of t
June 2022, Paper 2, Q7(c) (2 marks): The data book value of ΔH for the combustion of ethanol is –1367 kJ/mol. Give two reasons why the student’s value is much lower than the data book value. (2) 1
June 2022, Paper 2, Q7(d)(i) (4 marks): Calculate the bond energy of the C H bond, using information from the equation and the table. (4) C H bond energy = kJ/mol
June 2022, Paper 2, Q7(d)(ii) (2 marks): Complete the energy level diagram to show the products and ΔH. (2) Energy CH4 + 2O2
June 2022 (R), Paper 1, Q8(a)(ii) (1 mark): Give a reason why the student uses a polystyrene cup inside a glass beaker. (1)
June 2022 (R), Paper 1, Q8(a)(iv) (2 marks): The temperature at the start of the reaction is 19.7 °C. The temperature at the end of the reaction is 48.3 °C. Calculate the heat energy change, in joules, for
June 2022 (R), Paper 1, Q8(b)(i) (3 marks): The reaction between zinc and silver nitrate solution is exothermic. A mass of 0.65 g of zinc is added to excess silver nitrate solution. The heat energy change
June 2022 (R), Paper 2, Q7(c) (3 marks): Draw an energy level diagram for the reaction between nitrogen and hydrogen. Include the reactants, products and ΔH in your diagram. (3) energy QUESTION 7 CONTI
January 2022, Paper 2, Q5(b)(i) (2 marks): Label the diagram to show the activation energy (Ea) and the enthalpy change (ΔH) for this reaction. (2)
January 2022, Paper 2, Q7(b) (2 marks): Explain why the molar enthalpy change (ΔH) for the reaction between ester A and water is 0 kJ/mol. In your answer, refer to the bonds broken and the bonds forme
January 2022 (R), Paper 1, Q11(a) (6 marks): Discuss the advantages and disadvantages of each method. (6)
January 2022 (R), Paper 1, Q11(c)(i) (3 marks): Show that the energy change Q for this reaction is about 4000 J [mass of 1 cm3 of solution = 1.0 g] [for the solution, c = 4.2 J / g / °C] (3)
January 2022 (R), Paper 1, Q11(c)(ii) (3 marks): Calculate the molar enthalpy change (ΔH), in kJ / mol, for the reaction. (3) ΔH = kJ / mol
January 2022 (R), Paper 2, Q7(a) (1 mark): State the meaning of the term exothermic. (1)
January 2022 (R), Paper 2, Q7(b) (4 marks): The table gives the bond energies for the H H and H Cl bonds. Bond Cl H H H Bond energy in kJ / mol 436 431 Use the equation and information from the table to c
January 2022 (R), Paper 2, Q7(c) (3 marks): Explain why this reaction is exothermic. Refer to bond-breaking and bond-making in your answer. (3)
January 2022 (R), Paper 2, Q7(d) (4 marks): Complete the reaction profile diagram to show the position of the products, the enthalpy change (ΔH) and the activation energy (Ea) for the reaction. (4) Energy
November 2021, Paper 1, Q9(a)(i) (2 marks): Plot the student’s results on the grid. (2)
November 2021, Paper 1, Q9(a)(ii) (1 mark): Draw a curve of best fit, ignoring the anomalous result. (1) 17 16 15 14 Temperature in °C 13 12 11 10 0 1 2 3 4 5 Mass of hydrated sodium carbonate added in g
November 2021, Paper 1, Q9(a)(iii) (2 marks): Explain why it is better to use a polystyrene cup instead of a glass beaker in this experiment. (2)
November 2021, Paper 1, Q9(a)(iv) (1 mark): Suggest a reason for the anomalous result. (1)
November 2021, Paper 1, Q9(a)(v) (1 mark): State how the results show that all the dilute hydrochloric acid has reacted. (1)
November 2021, Paper 1, Q9(a)(vi) (2 marks): Use the results of the experiment to explain the type of reaction that occurs when sodium carbonate is added to dilute hydrochloric acid. (2)
November 2021, Paper 1, Q10(d)(i) (3 marks): Calculate the heat energy change (Q) in joules. [specific heat capacity of water is 4.2 J/g/°C] (3) Q = J
November 2021, Paper 1, Q10(d)(ii) (2 marks): The student burns 0.0200 mol of ethanol. Use this information and your value for Q to calculate the molar enthalpy change (ΔH), in kJ/mol, for the combustion of
November 2021, Paper 2, Q7(b) (3 marks): Hydrogen gas reacts with fluorine gas to form hydrogen fluoride gas. H2(g) + F2(g) → 2HF(g) The table gives some bond energies. Bond Bond energy in kJ/mol H H 4
November 2021, Paper 2, Q7(c) (3 marks): Draw an energy level diagram for the reaction between hydrogen and fluorine. Label the enthalpy change, ΔH. (3) Energy
June 2021, Paper 1, Q7(b)(i) (2 marks): Complete the table by giving the temperatures to the nearest 0.1 °C. (2) temperature of the acid at the start in °C highest temperature reached in °C temperatur
June 2021, Paper 1, Q7(b)(ii) (2 marks): Show that the heat energy change (Q) for this reaction is about 2200 J. [mass of 1.0 cm3 of solution = 1.0 g] [for the solution, c = 4.2 J/g/°C] (2)
June 2021, Paper 1, Q7(b)(iii) (4 marks): The mass of magnesium used by the student was 0.12 g. Calculate the value of the enthalpy change (ΔH), in kilojoules per mole of magnesium, for the reaction bet
January 2021, Paper 1, Q7(b)(i) (2 marks): Complete the table, giving all values to the nearest 0.1 °C. (2) temperature in °C after adding the lithium oxide temperature in °C before adding the lithium ox
January 2021, Paper 1, Q7(b)(ii) (4 marks): Calculate the heat energy change in the reaction. Give your answer to two significant figures. [c = 4.2 J / g / °C] (4) heat energy change = J
January 2021, Paper 1, Q7(b)(iii) (3 marks): In another experiment the scientist obtains these results. amount of lithium oxide in mol 0.0580 heat energy change in J 5210 Calculate the molar enthalpy chang
January 2021, Paper 1, Q7(b)(iv) (1 mark): Give a reason why the scientist does the experiment in a polystyrene cup. (1)
January 2021, Paper 2, Q5(d)(ii) (3 marks): Draw an energy level diagram for the reaction between aluminium and iron(III) oxide. (3) Energy
January 2021 (R), Paper 1, Q9(c)(i) (1 mark): Suggest what could be added to the apparatus to improve the experiment. (1)
January 2021 (R), Paper 1, Q9(c)(ii) (2 marks): Explain a change to the method that would improve the accuracy of the experiment. (2)
January 2021 (R), Paper 1, Q9(d)(i) (3 marks): Calculate the energy change, Q, in joules for this reaction. [mass of 1.0 cm3 of mixture = 1.0 g] [for the mixture, c = 4.2 J/g/°C] (3) Q = J
January 2021 (R), Paper 1, Q9(d)(ii) (2 marks): In the student’s reaction between hydrochloric acid and sodium hydroxide, 0.050 mol of water forms. Calculate the molar enthalpy change, ΔH, in kJ/mol for this
January 2021 (R), Paper 2, Q5(c) (2 marks): The decomposition of hydrogen peroxide solution is exothermic. On the diagram, draw and label the reaction profiles for the reaction  without a catalyst  with
January 2021 (R), Paper 2, Q5(d)(i) (1 mark): Use this information to calculate the total amount of energy needed to break all the bonds in two moles of H2O2 (1) energy needed = kJ
January 2021 (R), Paper 2, Q5(d)(ii) (1 mark): Use this information to calculate the total amount of energy released when all the bonds in two moles of H2O are formed. (1) energy released = kJ
January 2021 (R), Paper 2, Q5(d)(iii) (2 marks): Use the value of ΔH and your answers for (i) and (ii) to calculate the bond energy, in kJ/mol, for the O O bond. (2) bond energy = kJ/mol
November 2020, Paper 1, Q8(a)(i) (1 mark): Name the piece of apparatus the student should use to add the distilled water to the polystyrene cup. (1)
November 2020, Paper 1, Q8(a)(ii) (1 mark): The student stirs the solution to help the solid dissolve more quickly. Suggest another reason why the student stirs the solution. (1)
November 2020, Paper 1, Q8(a)(iii) (1 mark): State the colour of the copper(II) sulfate solution. (1)
November 2020, Paper 1, Q8(b) (3 marks): The diagram shows the temperatures in one experiment. 25 30 °C °C 20 25 initial temperature maximum temperature Complete the table, giving all values to the nea
November 2020, Paper 1, Q8(c)(i) (2 marks): Show that the heat energy change (Q) in this second experiment is approximately 700 J. [for water, c = 4.2 J/g/°C] [mass of 1.0 cm3 of water = 1.0 g] (2)
November 2020, Paper 1, Q8(c)(ii) (4 marks): In this experiment the student uses 1.70 g of the anhydrous copper(II) sulfate. Calculate the molar enthalpy change (ΔH) in kJ/mol. Include a sign in your answe
November 2020, Paper 1, Q8(d) (2 marks): Another student does a similar experiment but uses hydrated copper(II) sulfate instead of anhydrous copper(II) sulfate. The table shows his results. initial tem
November 2020, Paper 2, Q5(b)(ii) (4 marks): The equation for the reaction between butadiene and bromine can be shown using displayed formulae. H H H H H H C C H H C C Br → + 2Br H C C C C H H H Br Br Br B
November 2020, Paper 2, Q5(c)(iii) (4 marks): The equation for the combustion of butadiene in excess oxygen is 2C4H6 + 11O2 → 8CO2 + 6H2O The enthalpy change for this reaction, ΔH, is – 3446 kJ/mol. Complet
November 2020 (R), Paper 1, Q8(b)(i) (1 mark): State what is meant by the term exothermic. (1)
November 2020 (R), Paper 1, Q10(a)(ii) (2 marks): Explain why the student needs to stir the mixture. (2)
November 2020 (R), Paper 1, Q10(b) (2 marks): The table gives the temperatures of the solutions before the student mixes them. potassium hydroxide solution 17.8 °C dilute hydrochloric acid 18.4 °C Calculate
November 2020 (R), Paper 1, Q10(c)(i) (2 marks): Complete the table by giving the missing information. Give both temperatures to the nearest 0.1 °C. (2) mean temperature at start in °C temperature at end in °C
November 2020 (R), Paper 1, Q10(c)(ii) (3 marks): Show that the heat energy change, Q, in the student’s experiment is about 1100 J. [for the mixture, c = 4.2 J/g/°C] [mass of 1.0 cm3 of mixture = 1.0 g] (3)
November 2020 (R), Paper 1, Q10(c)(iii) (3 marks): The student uses 0.020 mol of potassium hydroxide in his experiment. Calculate the enthalpy change (ΔH) in kJ/mol, for 1.0 mol of potassium hydroxide. Include a
November 2020 (R), Paper 2, Q7(b)(i) (2 marks): Use values from the table to calculate the energy needed to break all the bonds in the reactants. (2) energy needed kJ
November 2020 (R), Paper 2, Q7(b)(ii) (2 marks): Use values from the table to calculate the energy released when all the bonds in the products are formed. (2) energy released kJ
November 2020 (R), Paper 2, Q7(b)(iii) (1 mark): Calculate the molar enthalpy change (ΔH) in kJ/mol, for the complete combustion of ethanol. Include a sign in your answer. (1) ΔH = kJ/mol
January 2020, Paper 1, Q3(c)(i) (1 mark): State the meaning of the term exothermic. (1)
January 2020, Paper 1, Q6(b) (3 marks): The diagram shows the thermometer readings for this reaction. 20 25 °C °C 15 20 before adding zinc after adding zinc Complete the table, giving all values to th
January 2020, Paper 1, Q6(c)(i) (2 marks): This student uses a polystyrene cup instead of a glass beaker. Explain why a polystyrene cup is better than a glass beaker in this investigation. (2)
January 2020, Paper 1, Q6(c)(ii) (3 marks): Give three factors that the student should keep constant in this investigation. (3) 1 2 3
January 2020, Paper 1, Q9(a) (1 mark): Suggest why the student measures the mass of the spirit burner and fuel immediately after heating the water. (1)
January 2020, Paper 1, Q9(c)(i) (3 marks): Show that the heat energy change, Q, to raise the temperature of 100 cm3 of water by 30 °C is approximately 13 kJ. [mass of 1.0 cm3 of water = 1.0 g] [c for wat
January 2020, Paper 1, Q9(c)(ii) (3 marks): The student burns 0.96 g of methanol, CH3OH Calculate the molar enthalpy change, ΔH, in kJ/mol, for the combustion of methanol. Include a sign in your answer. [
January 2020, Paper 1, Q9(d)(i) (2 marks): Plot the data values from the table on the grid. Draw a straight line of best fit. (2) Number of carbon atoms per molecule 0 1 2 3 4 5 6 0 –500 –1000 –1500 –200
January 2020, Paper 1, Q9(d)(ii) (2 marks): Deduce the value of ΔH for an alcohol with six carbon atoms per molecule. Show on the graph how you obtained your answer. (2) ΔH = kJ/mol
January 2020, Paper 1, Q9(d)(iii) (1 mark): State the relationship between ΔH and the number of carbon atoms per molecule. (1)
January 2020, Paper 2, Q5(c)(i) (3 marks): Use the values in the table to calculate the enthalpy change, ΔH, for the reaction. Include a sign in your answer. (3) ΔH = kJ
January 2020, Paper 2, Q5(c)(ii) (2 marks): Complete the energy level diagram to show the position of the products and the enthalpy change, ΔH, for the reaction. (2) 2H2O2 energy
January 2020 (R), Paper 1, Q6(b)(i) (2 marks): Calculate the heat energy change, in joules, for the reaction. [mass of 1.00 cm3 of solution = 1.00 g] [c for the solution = 4.2 J/g/ °C] (2) heat energy change
January 2020 (R), Paper 1, Q6(b)(ii) (2 marks): Explain why it is better to use a polystyrene cup rather than a glass beaker in this experiment. (2)
January 2020 (R), Paper 1, Q6(c)(i) (3 marks): A mass of 0.500 g of zinc is reacted with an excess of copper(II) sulfate solution. The heat energy change is 1.67 kJ. Calculate the molar enthalpy change, ǻH,
January 2020 (R), Paper 1, Q7(c) (3 marks): Another student investigates how the temperature changes when the sodium hydroxide solution is added to the hydrochloric acid. The hydrochloric acid and the sod
January 2020 (R), Paper 2, Q6(b)(iv) (3 marks): The reaction between ethene and hydrogen is exothermic. Complete the reaction profile diagram, including labels for the activation energy and the enthalpy chang
January 2020 (R), Paper 2, Q6(c) (3 marks): The reaction between ethene and hydrogen can be represented using displayed formulae. H H H H H –o C=C + H H C C H H H H H Bond energy in Bond kJ/mol C C 612 C
June 2019, Paper 1, Q12(a) (2 marks): Use the results of the experiment to explain what type of reaction is taking place when ammonium nitrate is added to water. (2) ((i 18
June 2019, Paper 1, Q12(b) (3 marks): Show that the heat energy change, Q, is about 2400 J. [mass of 1.00 cm3 of solution = 1.00 g] [for the solution, c = 4.18 J/g/ °C ] (3) Q = J
June 2019, Paper 1, Q12(c) (4 marks): Use your answer to part (b) to calculate the enthalpy change, ∆H, in kilojoules per mole of ammonium nitrate. [Mr of ammonium nitrate = 80.0] Include a sign in
June 2019, Paper 2, Q5(a)(i) (1 mark): Use the data in the tables to calculate the total amount of energy required to break all of the bonds in the reactants. (1) energy required = kJ
June 2019, Paper 2, Q5(a)(ii) (1 mark): Use the data in the tables to calculate the total amount of energy released when all of the bonds in the products are made. (1) energy released = kJ
June 2019, Paper 2, Q5(a)(iii) (3 marks): Calculate the enthalpy change, ∆H, in kJ/mol, for the reaction. Include a sign in your answer. (3) ∆H = kJ/mol
June 2019, Paper 2, Q5(b) (2 marks): Explain, in terms of bonds broken and bonds made, why this reaction is exothermic. (2)
June 2019, Paper 2, Q5(c) (3 marks): Draw an energy level diagram for the reaction between N2H4 and H2O2 (3) energy
June 2019 (R), Paper 1, Q6(b)(iii) (1 mark): State the meaning of the term exothermic. (1)
June 2019 (R), Paper 1, Q8(a)(ii) (2 marks): Explain why a polystyrene cup is used rather than a beaker. (2)
June 2019 (R), Paper 1, Q8(a)(iii) (1 mark): Give a safety precaution that the student should take when using sodium hydroxide solution. (1)
June 2019 (R), Paper 1, Q8(b)(i) (3 marks): Plot the results on the grid. Draw a straight line of best fit through the first five points and another straight line of best fit through the last four points.
June 2019 (R), Paper 1, Q8(b)(ii) (2 marks): The point where the lines cross shows • the volume of acid needed to exactly neutralise the alkali • the maximum temperature reached Use your graph to determine
June 2019 (R), Paper 1, Q10(b)(i) (3 marks): Show that the heat energy change (Q) is about 1300 J. [for the solution, c = 4.18 J/g/°C] [mass of 1.00 cm3 of solution = 1.00 g] (3)
June 2019 (R), Paper 1, Q10(b)(iii) (3 marks): Calculate the value of the enthalpy change (ΔH), in kilojoules per mole, for the reaction between zinc and copper(II) sulfate. Include a sign in your answer. (3

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