Practical: investigate the specific heat capacity of a substance

3 marks · Normal

Describe a method that a student could use to find the specific heat capacity of water using an electric heater. Include the main steps and measurements the student would need to make.

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

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Must show: Weighs mass of water, Measures initial and final temperature, Measures voltage, current and time for heater, Describes calculation using these values

Also accept: Mentions use of beaker with insulation

Common mistakes: Not measuring mass; Not using correct formula

Show mark scheme and worked solution

Marking points

M1 · 1 mark · Student describes measuring the mass of water

M2 · 1 mark · Student describes measuring initial and final temperature, and the required energy supplied (from V, I, t)

M3 · 1 mark · Student explains how to use the values to calculate the specific heat capacity using the given formula

Worked solution

First, measure and record the mass of water in a beaker using a balance. Insert the immersion heater and a thermometer into the water. Record the initial temperature of the water. Switch on the heater and note the voltage, current, and the time the heater is operated. When a suitable temperature rise is reached, record the final temperature. Calculate the energy supplied using Q = V × I × t and temperature increase. Then calculate the specific heat capacity using c = Q/(m × Δθ).