A student is investigating the specific heat capacity of cooking oil. She pours a measured volume of oil into an insulated container, adds an electrical immersion heater, and records the temperature every 30 seconds. She repeats the experiment replacing the oil with the same volume of water. Describe how the student should carry out a fair and reliable investigation, and explain what she should do with her repeated results to improve the quality of the data.

OCR A-Level Physics B: Advancing Physics (H557) — 1.1 Practical skills assessed · Describe · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

The student wants to compare the specific heat capacity of cooking oil with that of water using an electrical immersion heater and a thermometer.

Model answer (5 marks)

1. Use the same mass (or volume) of oil and water in each experiment.
2. Use the same heater power/voltage and current, or heat for the same length of time, so the energy input is identical.
3. Start both experiments at the same initial temperature to avoid bias.
4. Repeat the experiment for each liquid and calculate a mean (average) temperature reading or result.
5. Identify and exclude any anomalous results before calculating the mean to improve data quality.

Examiner tips

  • Use bullet points or numbered list to show each criterion clearly.
  • Show the calculation of the mean if you include data.
  • Mention that excluding outliers is part of data reliability.

Common mistakes

  • Using different volumes or masses of liquids.
  • Changing heater settings between runs.
  • Failing to average repeated trials or ignoring outliers.

Mark scheme (5 marks)

  1. Use the same mass (or volume) of oil and water in each experiment
  2. Use the same heater power / voltage and current / energy input for both liquids, or heat for the same length of time
  3. Start both experiments at the same initial temperature
  4. Repeat the experiment (for each liquid) and calculate a mean (average) temperature reading / result
  5. Identify and exclude anomalous results before calculating the mean

Key terms in this question

specific heat capacity

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