The specific latent heat of fusion of ice is 334 000 J/kg334\,000\ \text{J/kg}334000 J/kg and the specific heat capacity of water is 4200 J/kg ∘C4200\ \text{J/kg}\ ^\circ\text{C}4200 J/kg ∘C. Which needs more energy, melting 1.0 kg of ice at 0 ∘C0\ ^\circ\text{C}0 ∘C, or heating 1.0 kg of water from 0 ∘C0\ ^\circ\text{C}0 ∘C to 80 ∘C80\ ^\circ\text{C}80 ∘C?
Melting the ice, because it needs 334 000 J and the heating needs 33 600 J
Melting the ice, because a change of state always needs more energy than heating
Heating the water, because it needs 336 000 J and the melting needs 334 000 J
Neither, because both processes need almost exactly 334 000 J of energy
40 exam-style questions on AQA GCSE Physics 3.2 Internal energy and energy transfers, covering 3.2.1 Internal energy, 3.2.2 Temperature changes in a system and specific heat capacity, and 3.2.3 Changes of state and specific latent heat. Each one has a worked solution and a mark scheme showing where the marks go.