Changes of state: OCR GCSE Combined Science A questions

Every OCR GCSE Combined Science A exam question on P1.2 Changes of state, 2018–2025, with its mark scheme and examiner’s report.

All 84 questions on Changes of state, as a list

June 2025, Physics Paper 5 Foundation, Q13(a) (2 marks): When the cool pack melts, the density of the chemical inside decreases. Explain why the density decreases. Use ideas about particles. [2]
June 2025, Physics Paper 5 Foundation, Q13(b) (4 marks): The cool pack contains 0.125 kg of a chemical with a specific latent heat of 425 000 J / kg. Calculate the energy needed to completely melt the chemical in the
June 2025, Physics Paper 5 Foundation, Q13(c) (2 marks): The table gives data on three chemicals which could be used in a cool pack. Chemical A B C Melting point (°C) 60 0 –5 Specific latent heat (J / kg) 510 000 334
June 2025, Physics Paper 5 Foundation, Q14 (6 marks): 14* Some air is in a closed container. The table shows its pressure at two temperatures. Temperature (°C) 2 100 Pressure (kN / m2) 110 140 Explain how the press
June 2025, Physics Paper 6 Foundation, Q14(a)(ii) (3 marks): The kettle contains 0.50 kg of water at 20 °C. Calculate the minimum change in thermal energy needed to raise the temperature of the water to 100 °C. The specif
June 2024, Physics Paper 5 Foundation, Q13(a) (1 mark): Which statement describes how to get accurate results? Tick (3) one box. Add some ice to the beaker. Use the heater for a very short time. Wrap insulation aroun
June 2024, Physics Paper 5 Foundation, Q13(b) (1 mark): Here are some steps in the method for this experiment. The steps are not in the correct order. Write numbers in the boxes next to each step to show the correct
June 2024, Physics Paper 5 Foundation, Q13(e) (3 marks): In another set of results 0.015 kg of ice melts. The energy transferred by the heater is 5010 J. Calculate the specific latent heat of ice. Use the Equation She
June 2024, Physics Paper 11 Higher, Q7 (1 mark): A sealed rigid container of air is in a room at 20 °C. The container is then placed in a refrigerator at 4 °C. Which row explains what happens to the speed of t
June 2024, Physics Paper 11 Higher, Q14(a)(i) (3 marks): Here are the first set of results from the experiment. Starting temperature of ice cube = 0 °C Mass of water = 0.2 kg Starting temperature of water = 30 °C Fina
June 2024, Physics Paper 11 Higher, Q14(a)(ii) (3 marks): Here are the second set of results from the experiment. Change in thermal energy of the water = 15 000 J Energy needed to raise temperature of melted ice = 12 6
June 2024, Physics Paper 11 Higher, Q14(a)(iii) (1 mark): The ice must be dried with a paper towel before starting the experiment. Suggest why. [1]
June 2024, Physics Paper 11 Higher, Q14(b) (2 marks): Describe how the terms specific latent heat and specific heat capacity are different. [2]
June 2023, Physics Paper 5 Foundation, Q10 (1 mark): Two rooms have the same fixed volume. They contain identical gases at the same pressure. Room H is at a higher temperature than room L. Which statement is corre
June 2023, Physics Paper 5 Foundation, Q12(a) (1 mark): Suggest a way to measure the time taken. [1]
June 2023, Physics Paper 5 Foundation, Q12(b) (2 marks): The mass of the water is 0.2 kg. The temperature change is 50 °C. The specific heat capacity of water is 4200 J / kg °C. Calculate the thermal energy transferre
June 2023, Physics Paper 5 Foundation, Q12(d)(i) (1 mark): The student says, ‘Bunsen burner A has the highest power.’ Explain how the graph shows this. [1]
June 2023, Physics Paper 5 Foundation, Q12(d)(ii) (1 mark): The manufacturer says, ‘The line on the graph for Bunsen burner B is not accurate. The power of the Bunsen burners should be the same.’ Both Bunsen burners are
June 2023, Physics Paper 6 Foundation, Q5 (1 mark): A 200 g bar of chocolate is melted in a saucepan. The specific latent heat of melting chocolate is 31.2 J / g. How much energy is needed to melt the bar of choc
June 2023, Physics Paper 11 Higher, Q2 (1 mark): Two rooms have the same fixed volume. They contain identical gases at the same pressure. Room H is at a higher temperature than room L. Which statement is corre
June 2023, Physics Paper 11 Higher, Q14(a) (1 mark): Student A uses point P on the graph to calculate the gradient of the line of best fit. Explain why student A’s calculation is incorrect. [1]
June 2023, Physics Paper 11 Higher, Q14(b) (3 marks): Calculate the gradient of the line of best fit on the graph. Give your answer to 2 significant figures. Gradient = °C / s [3]
June 2023, Physics Paper 11 Higher, Q14(c)(i) (1 mark): What is the significance of the y intercept of the line on the graph? [1]
June 2023, Physics Paper 11 Higher, Q14(c)(ii) (1 mark): What is the significance of the gradient of the line on the graph? [1]
June 2023, Physics Paper 11 Higher, Q14(d) (3 marks): Student B repeats the experiment. The gradient of their line of best fit is 0.25 °C / s. The specific heat capacity of water is 4200 J / kg °C. Use student B’s
June 2022, Physics Paper 5 Foundation, Q16(a) (2 marks): Describe the difference between specific heat capacity and specific latent heat. [2]
June 2022, Physics Paper 5 Foundation, Q16(b)(i) (1 mark): Using the graph, describe the relationship between temperature rise and specific heat capacity. [1]
June 2022, Physics Paper 5 Foundation, Q16(b)(ii) (2 marks): A liquid has a specific heat capacity of 1600 J / kg °C. Use the graph to estimate the temperature rise of the liquid. Temperature rise = °C [2]
June 2022, Physics Paper 5 Foundation, Q16(b)(iii) (1 mark): State one assumption you made when answering (b)(ii). [1]
June 2022, Physics Paper 5 Foundation, Q16(c) (1 mark): A student calculates the specific heat capacity of water. The student does one experiment and gets this result: • Student’s value = 4250 J / kg °C. • Textbook v
June 2022, Physics Paper 6 Foundation, Q17(a)(i) (3 marks): Student A wants to calculate the thermal energy transferred to the saucepan of water. These are the steps in their method: 1 Measure the volume of water with a
June 2022, Physics Paper 6 Foundation, Q17(a)(ii) (1 mark): Student A suggests wrapping insulation around the saucepan in Fig. 17.1. Suggest another way student A can improve their experiment. [1]
June 2022, Physics Paper 6 Foundation, Q17(b) (4 marks): Student B uses the immersion heater in Fig. 17.2 to increase the temperature of water in a beaker. Fig. 17.2 Battery Voltmeter Water 1 2 0 3 A Beaker Immersion
June 2022, Physics Paper 11 Higher, Q4 (1 mark): A ball is inflated with air. In which environment will the air inside the ball have the highest pressure? A In a refrigerator (3 °C) B In a house (18 °C) C Outs
June 2022, Physics Paper 11 Higher, Q11(a) (2 marks): Describe the difference between specific heat capacity and specific latent heat. [2]
June 2022, Physics Paper 11 Higher, Q11(b)(i) (1 mark): Using the graph, describe the relationship between temperature rise and specific heat capacity. [1]
June 2022, Physics Paper 11 Higher, Q11(b)(ii) (2 marks): A liquid has a specific heat capacity of 1600 J / kg °C. Use the graph to estimate the temperature rise of the liquid. Temperature rise = °C [2]
June 2022, Physics Paper 11 Higher, Q11(b)(iii) (1 mark): State one assumption you made when answering (b)(ii). [1]
June 2022, Physics Paper 11 Higher, Q11(c) (1 mark): A student calculates the specific heat capacity of water. The student does one experiment and gets this result: • Student’s value = 4250 J / kg °C. • Textbook v
June 2022, Physics Paper 12 Higher, Q11(a)(i) (3 marks): Student A wants to calculate the thermal energy transferred to the saucepan of water. These are the steps in their method: 1 Measure the volume of water with a
June 2022, Physics Paper 12 Higher, Q11(a)(ii) (1 mark): Student A suggests wrapping insulation around the saucepan in Fig. 11.1. Suggest another way student A can improve their experiment. [1]
June 2022, Physics Paper 12 Higher, Q11(b) (4 marks): Student B uses the immersion heater in Fig. 11.2 to increase the temperature of water in a beaker. Fig. 11.2 Battery Voltmeter Water 1 2 0 3 A Beaker Immersion
November 2021, Physics Paper 5 Foundation, Q9 (1 mark): A teacher is distilling water using the equipment shown in the diagram. Distillation involves evaporating and condensing the water. Water condenses Water evapor
November 2021, Physics Paper 5 Foundation, Q16(c)(i) (2 marks): The specific latent heat of vaporisation is the energy transferred when 1 kg of a substance changes from liquid to gas. Calculate the amount of energy needed to
November 2021, Physics Paper 5 Foundation, Q16(c)(ii) (2 marks): The energy needed to heat 1 kg of water by 1 °C is 4200 J. The energy needed to evaporate 1 kg of water is 2 256 000 J. This is much more than 4200 J. Explain w
November 2021, Physics Paper 6 Foundation, Q12(d)(i) (1 mark): Complete the missing label on the diagram. [1]
November 2021, Physics Paper 6 Foundation, Q12(d)(ii) (2 marks): • The specific heat capacity of the block is 500 J / kg °C. • The mass of the block is 0.5 kg. • Its temperature increases by 20 °C. Calculate the energy transf
November 2021, Physics Paper 11 Higher, Q1 (1 mark): A teacher is distilling water using the equipment shown in the diagram. Distillation involves evaporating and condensing the water. Water condenses Water evapor
November 2021, Physics Paper 11 Higher, Q7 (1 mark): This apparatus is used to measure the pressure of a fixed volume of gas. Pressure gauge Thermometer Water Gas When the temperature of water increases what happe
November 2021, Physics Paper 11 Higher, Q11(c)(i) (2 marks): The specific latent heat of vaporisation is the energy transferred when 1 kg of a substance changes from liquid to gas. Calculate the amount of energy needed to
November 2021, Physics Paper 11 Higher, Q11(c)(ii) (2 marks): The energy needed to heat 1 kg of water by 1 °C is 4200 J. The energy needed to evaporate 1 kg of water is 2 256 000 J. This is much more than 4200 J. Explain w
November 2021, Physics Paper 12 Higher, Q15(d)(i) (3 marks): One of the students says, ‘the temperature of the water in the bowl increases when the water drips into it’. 1 droplet of water transfers 5.04 × 10−4 J of energ
November 2021, Physics Paper 12 Higher, Q15(d)(ii) (2 marks): In 1847, James Joule did experiments at the bottom of a waterfall. He was unable to measure the temperature rise of the water. Suggest two reasons why. 1 2 [2]
November 2020, Physics Paper 5 Foundation, Q10 (1 mark): Which row of the table describes a physical change? 10 Process Material A Can be reversed Keeps new properties when reversed. Returns to original properties whe
November 2020, Physics Paper 5 Foundation, Q11 (3 marks): An aerosol canister contains a non-flammable gas at high pressure. The aerosol canister should 11 not be exposed to high temperatures. - Aerosol canister contai
November 2020, Physics Paper 5 Foundation, Q13(a) (1 mark): Fig. 13.3 is a model of particles in salol. Fig. 13.3 In which part of the graph, A, B or C, would the particles look like those in Fig. 13.3? Tick (r) one box.
November 2020, Physics Paper 5 Foundation, Q13(b) (1 mark): What is the melting point of salol? Melting point = ...°C [1]
November 2020, Physics Paper 5 Foundation, Q13(c): In which part of the graph, A, B or C, is salol a solid and a liquid? Tick (V) one box. B C 111
November 2020, Physics Paper 5 Foundation, Q13(d) (4 marks): Complete the sentences using the words or phrases below. You can use each word or phrase once, more than once, or not at all. increases stays the same break dec
November 2020, Physics Paper 5 Foundation, Q13(e)(i) (1 mark): The student is given 20 grams (g) of salol. What is the mass of salol in kilograms (kg)? Mass = .. kg [1]
November 2020, Physics Paper 5 Foundation, Q13(e)(ii) (2 marks): The specific latent heat of fusion of salol is 89700 J/kg. How much thermal energy is needed to completely melt 0.01 kg of salol? Use an equation from the Data
November 2020, Physics Paper 6 Foundation, Q16(b)(ii) (3 marks): The beaker contains 0.2 kg of water. The specific heat capacity of water is 4200 J / kg °C. Calculate the change in thermal energy in the water after 5 minutes.
November 2020, Physics Paper 11 Higher, Q2 (1 mark): Which row of the table describes a physical change? 2 Process Material Keeps new properties when reversed. A Can be reversed Returns to original properties when
November 2020, Physics Paper 11 Higher, Q7 (1 mark): In an experiment, it takes 3006 J of energy to melt an ice cube. 7 The ice cube has a mass of 0.009 kg. Calculate the specific latent heat of melting for ice. U
November 2020, Physics Paper 11 Higher, Q8 (1 mark): A student heats 4 blocks using the same heater for the same amount of time. 8 Each block has the same mass but a different specific heat capacity. Which block w
November 2020, Physics Paper 11 Higher, Q12 (3 marks): An aerosol canister may contain a non-flammable gas at high pressure. 12 Aerosol canister containing a non-flammable gas The aerosol canister should not be expo
November 2020, Physics Paper 12 Higher, Q11(b)(ii) (3 marks): The beaker contains 0.2 kg of water. The specific heat capacity of water is 4200 J / kg °C. Calculate the change in thermal energy in the water after 5 minutes.
June 2019, Physics Paper 5 Foundation, Q3 (1 mark): A sealed boiling tube contains gas. Bung Boiling tube Gas Heat The boiling tube is heated. What happens? A The particles in the gas evaporate. B The particles i
June 2019, Physics Paper 5 Foundation, Q10 (1 mark): An ice cube and container are placed on an electronic balance on a hot day. The container is sealed. Sealed container Ice cube Electronic balance 88.88g Which r
June 2019, Physics Paper 6 Foundation, Q7 (1 mark): The specific latent heat for melting ice is 334 000 J / kg. Calculate the thermal energy needed to melt 2.0 kg of ice. A 167 J B 668 J C 167 000 J D 668 000 J Y
June 2019, Physics Paper 11 Higher, Q2 (1 mark): An ice cube and container are placed on an electronic balance on a hot day. The container is sealed. Sealed container Ice cube Electronic balance 88.88g Which r
June 2018, Physics Paper 5 Foundation, Q8 (1 mark): Which row, A, B, C or D shows the largest change in thermal energy? Mass (kg) Specific heat Temperature change capacity (J/kg °C) (°C) A 1 4200 40 B 1 4200 20 C
June 2018, Physics Paper 5 Foundation, Q13 (6 marks): 13* The graph below shows the change in temperature of a material as it cools. 70 60 50 Temperature (°C) 40 30 20 Time Describe the graph and explain what it te
June 2018, Physics Paper 6 Foundation, Q14(a) (2 marks): What two other pieces of apparatus does the scientist need for this experiment? 1. 2. [2]
June 2018, Physics Paper 6 Foundation, Q14(b)(ii) (1 mark): The immersion heater is placed at the bottom of the beaker. Suggest why. [1]
June 2018, Physics Paper 6 Foundation, Q14(d)(ii) (3 marks): The scientist writes down more information about her experiment. • Mass of water = 150 g • Specific heat capacity of water = 4200 J / kg °C • Temperature increa
June 2018, Physics Paper 11 Higher, Q2 (1 mark): Which of the following is a definition for specific heat capacity in physics? A Energy needed to increase the temperature of 1 g of material by 1 °C. B Energy n
June 2018, Physics Paper 11 Higher, Q7 (1 mark): A student is heating substances in four identical beakers A, B, C and D. Some information about the contents of the beakers is shown below. A B 2 kg 1 kg Specif
June 2018, Physics Paper 11 Higher, Q13 (6 marks): 13* A student removes a material from a freezer and heats it up. He uses a heater with a constant power output. He then plots a heating curve of the material as
June 2018, Physics Paper 12 Higher, Q16(a) (2 marks): Suggest two ways to ensure the scientist obtains accurate results. 1. 2. [2]
June 2018, Physics Paper 12 Higher, Q16(b)(i) (1 mark): Is there a random error in this experiment? Explain your answer. [1]
June 2018, Physics Paper 12 Higher, Q16(b)(ii) (1 mark): The scientist thinks the point labelled B on the graph is an anomaly. Is she correct? Explain your answer. [1]
June 2018, Physics Paper 12 Higher, Q16(c)(i) (2 marks): Calculate the gradient (slope) of the graph. Answer = °C / s [2]
June 2018, Physics Paper 12 Higher, Q16(c)(ii) (4 marks): The scientist writes down more results. • 0.1 kg of water used • Power of immersion heater = 12.8 W Use the equations: Energy transferred = Power × Time Change

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