Melting, boiling and evaporation: past paper questions
Real questions on melting, boiling and evaporation
The newest 20 of 22 written questions. Open one to see it on the real paper.
- 0972/41 · October/November 2024 · Q4b(iii)[3]
The water in the dish evaporates. Explain, in terms of the water molecules, what is meant by evaporation.
See it on the paper → - 0972/42 · May/June 2024 · Q4a[2]
State two ways that evaporation differs from boiling.
See it on the paper → - 0972/31 · October/November 2023 · Q3c(iii)[1]
State the temperature at which the water boils at standard atmospheric pressure. temperature = °C
See it on the paper → - 0972/32 · May/June 2022 · Q5b[3]
Some of the hot liquid is poured out of the flask into a shallow dish. Explain how evaporation causes the liquid to cool.
See it on the paper → - 0972/41 · May/June 2022 · Q3a[3]
Explain, in terms of molecules, how evaporation cools the water in the cloth.
See it on the paper → - 0972/41 · May/June 2022 · Q5a[2]
State what is meant by boiling point.
See it on the paper → - 0972/31 · October/November 2021 · Q4a[4]
A substance cools from 50 °C to 5.0 °C. Its melting point is 20 °C. The substance takes 30 minutes to cool from 50 °C to its melting point. The substance takes a total time of 80 minutes to cool from 50 °C to 5.0 °C. On Fig. 4.1, sketch a graph that shows how the temperature of the substance varies with time as it cool...
See it on the paper → - 0972/41 · October/November 2021 · Q2c(i)[2]
Explain why this ice melts.
See it on the paper → - 0972/41 · October/November 2021 · Q2c(ii)[3]
Describe how to determine the specific latent heat of fusion of ice using this experiment. State any other measurements that the student needs to make.
See it on the paper → - 0972/41 · May/June 2021 · Q4b(iii)[3]
Eventually, the water reaches boiling point. Thermal energy from the hotplate is still being transferred to the water. Explain, in terms of molecules, the effect of this thermal energy on the water.
See it on the paper → - 0972/41 · May/June 2021 · Q4b(iv)[3]
The mass of the water decreases by 0.11 kg in 300 s. The specific latent heat of vaporisation of water is 2.3 × 10 6 J / kg. Calculate the rate at which the water gains thermal energy. rate of gain of energy =
See it on the paper → - 0972/41 · October/November 2020 · Q4c(i)[1]
Explain, in terms of molecules, why a supply of thermal energy is needed to change the liquid into a gas.
See it on the paper → - 0972/41 · October/November 2020 · Q4c(ii)[3]
The density of the liquid in the test-tube is 0.86 g / cm 3 . The volume of liquid in the test- tube is 50 cm 3 . The liquid reaches its boiling point. It now absorbs 18 000 J of thermal energy and all of the liquid changes into a gas. Calculate the specific latent heat of vaporisation of this liquid. specific latent h...
See it on the paper → - 0972/32 · May/June 2020 · Q4b[3]
Some students heat water in a beaker. They measure the temperature every minute. They heat the water for 8 minutes until it boils, and then continue to heat it for a further 5 minutes. Describe and explain how the temperature of the water changes during the 13 minutes.
See it on the paper → - 0972/41 · May/June 2020 · Q4a[1]
State what is meant by boiling point.
See it on the paper → - 0972/41 · May/June 2020 · Q4b(iii)[3]
Water from the container evaporates and the temperature of the remaining water decreases slowly. Explain, in terms of molecules, why evaporation causes the temperature of the remaining water to decrease.
See it on the paper → - 0972/31 · May/June 2019 · Q6b(i)[2]
section X name explanation
See it on the paper → - 0972/31 · May/June 2019 · Q6b(ii)[2]
section Y name explanation
See it on the paper → - 0972/41 · May/June 2019 · Q5a(i)[2]
State two ways in which boiling differs from evaporation. 1. 2.
See it on the paper → - 0972/41 · May/June 2019 · Q5a(ii)[4]
Before injecting a patient, a doctor wipes a small amount of a volatile liquid on to the patient’s skin. Explain, in terms of molecules, how this procedure cools the patient’s skin.
See it on the paper →
What examiners said
This question was very well answered by most candidates who gained at least partial credit. Most candidates referred to evaporation happening only on the surface or there being no bubbles present in evaporation. These were alternative ways of expressing the same idea. Weaker candidates gave these as two differences and omitted to state that evaporation does not take place at a specific temperature...
— Examiner report, May/June 2024, 0972/42 Q4(a) (Cambridge)
The majority of candidates answered this correctly. The most common error was to give an incorrect value in kelvin.
— Examiner report, October/November 2023, 0972/31 Q3(c)(iii) (Cambridge)
Only stronger candidates answered this fully correctly but other candidates gained partial credit. The most common error was failing to state that the average energy of the particles remaining in the liquid decreased and so it cooled.
— Examiner report, May/June 2022, 0972/32 Q5(b) (Cambridge)
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