The table shows some data for water.
Table
| Quantity | Value |
|---|---|
| Specific heat capacity of water | 4200 J/kg ∘C4200\ \text{J/kg}\ {}^\circ\text{C}4200 J/kg ∘C |
| Specific latent heat of vaporisation of water | 2 260 000 J/kg2\,260\,000\ \text{J/kg}2260000 J/kg |
Energy E1 E_1\,E1 is needed to heat 1.0 kg of water from 20 ∘C20\ {}^\circ\text{C}20 ∘C to 100 ∘C100\ {}^\circ\text{C}100 ∘C.
Energy E2 E_2\,E2 is needed to turn 1.0 kg of water at 100 ∘C100\ {}^\circ\text{C}100 ∘C into steam.
Use the equations:
change in thermal energy=mass×specific heat capacity×change in temperature\text{change in thermal energy} = \text{mass} \times \text{specific heat capacity} \times \text{change in temperature}change in thermal energy=mass×specific heat capacity×change in temperature
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
How many times bigger is E2 E_2\,E2 than E1E_1E1?
0.150.150.15
5.45.45.4
6.76.76.7
272727
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.