# GCSE Questions: Kinetic Theory - Gases

Q2. Claire investigated the cooling effect of evaporation.

She used the equipment shown in the diagram to measure how the temperature of three different liquids changed as they evaporated.

(a) The temperature and volume of each liquid was the same at the start of the investigation.

State one further control variable in this investigation.

[1 mark]

(b) Give two advantages of using dataloggers and temperature probes compared to using a thermometer as shown below.

[2 marks]

(c) Claire's results are plotted on the graph below:

(i) Calculate the average rate of temperature decrease of liquid C between 0 and 100 seconds.

[3 marks]

(ii) Give one conclusion that can be made about the rate of temperature decrease of all three liquids from her results.

[1 mark]

[1 mark]

(iv) Gabriel did the same investigation but using a smaller volume of liquid than Claire. All other variables were kept the same.

What effect would this have on the results of Gabriel's investigation?

[1 mark]

(d) Explain how the evaporation of a liquid causes the temperature of the remaining liquid to decrease.

[3 marks]

[12 Marks TOTAL]