Question 3
FA student uses the apparatus in the Figure to find the specific latent heat of fusion of ice.
Figure
The student switches on the heater. The joulemeter shows that 16 700 J16\,700\ \text{J}16700 J of energy is transferred to the ice.
The mass of water collected in the beaker is 0.050 kg.
Use the equation: thermal energy for a change in state=mass×specific latent heat\text{thermal energy for a change in state} = \text{mass} \times \text{specific latent heat}thermal energy for a change in state=mass×specific latent heat
a.[3]
Calculate the specific latent heat of fusion of ice.
Give the unit.
b.[2]
Some of the ice melts because of energy from the warm room, not from the heater.
Explain how this affects the value of specific latent heat that the student calculates.
c.[1]
Suggest one change to the experiment that would reduce OR allow for this error.
1.2 Changes of state Questions
44 exam-style questions on OCR GCSE Physics 1.2 Changes of state, covering 1.2.1 Conservation of mass during changes of state, 1.2.2 Physical and chemical changes, 1.2.3 Heating, temperature and changes of state, 1.2.4 Specific heat capacity and specific latent heat, 1.2.5 Internal energy and temperature change, and 1.2.6 Energy transfer during a change of state. Each one has a worked solution and a mark scheme showing where the marks go.