Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
The energy involved in change of state
17 practice questions
Practice questions
1–10 of 17
Question 1
1 mark · Easy
Answer and see the solution →State what happens to the temperature of a substance during melting, while it is still being heated.
Question 2
1 mark · Easy
Answer and check →Which of the following best describes what happens to the energy supplied to a substance at its boiling point?
- A.It is used to raise the temperature further.
- B.It is used to increase the mass of the substance.
- C.It is used to overcome the forces between molecules.
- D.It is used to break the bonds inside the molecules.
Question 3
2 marks · Easy
Answer and see the solution →Describe what a temperature–time graph would look like for a substance that is being heated steadily as it melts from solid to liquid.
Question 4
2 marks · Easy
Answer and see the solution →Explain why the temperature of a substance does not change during boiling, even though energy is still being supplied.
Question 5
2 marks · Easy
Answer and see the solution →A student heats a solid and records its temperature every minute. Describe how the temperature readings would change if the student continues heating the substance until it has fully melted and then further increases the temperature.
Question 6
3 marks · Easy
Answer and see the solution →A student wants to demonstrate how the temperature of stearic acid (a solid) changes as it melts and then becomes a liquid.
(a)[1 mark]Describe one safety precaution the student should take while heating stearic acid.
(b)[2 marks]Explain what happens to the temperature of stearic acid as it is heated, melts, and then is fully in liquid form.
Question 7
2 marks · Easy
Answer and see the solution →A scientist records the temperature of a pure substance as it is heated steadily. The measured values are shown in the table below.
Temperature vs Time for a Substance being Heated Time (min) Temperature (°C) 0 20 2 40 4 60 6 80 8 80 10 100 Explain what the constant temperature at 80 °C from 6 to 8 minutes shows about what is happening to the substance.
Question 8
1 mark · Normal
Answer and check →Which statement best describes what happens during the boiling of a liquid?
- A.The temperature increases rapidly and then stops.
- B.The added energy is used to increase the speed of the particles.
- C.The energy supplied is used to overcome the forces between the particles, so temperature remains constant.
- D.The liquid evaporates only from the surface, with the temperature increasing all the time.
Question 9
3 marks · Normal
Answer and see the solution →Describe a practical method to obtain a temperature–time graph showing the change of state from solid to liquid for a substance such as naphthalene. Include details on how to make the experiment as accurate as possible.
Question 10
1 mark · Normal
Answer and see the solution →Why is it important to use a water bath instead of a direct flame when heating substances like naphthalene to study their change of state?