Some water is boiling at 100 ∘C100\ {}^\circ\text{C}100 ∘C. 50 g of the water turns into steam.
The specific latent heat of vaporisation of water is 2 260 000 J/kg2\,260\,000\ \text{J/kg}2260000 J/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
How much energy is transferred to the water to turn it into steam?
45 200 J45\,200\ \text{J}45200 J
113 000 J113\,000\ \text{J}113000 J
2 260 000 J2\,260\,000\ \text{J}2260000 J
113 000 000 J113\,000\,000\ \text{J}113000000 J
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.