Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Change of State
56 practice questions
Topics covered
Practice questions
21–25 of 25 · Easy
Question 21
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 22
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 23
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 24
4 marks · Easy
Answer and see the solution →A student investigates how heating a solid wax block causes it to change state.
(a)[2 marks]Describe how the arrangement and movement of particles change as the wax is heated from a solid to a liquid.
(b)[2 marks]Explain why the temperature of the wax stays constant for a short time during melting, even though energy is still being supplied.
Question 25
4 marks · Easy
Answer and see the solution →A student sets up a practical to investigate the specific heat capacity of a metal block.
(a)[2 marks]List two measurements the student must take to calculate the specific heat capacity.
(b)[2 marks]State and explain one reason why the calculated value of the specific heat capacity might be higher than the true value.