Specific latent heat – melting ice
A PowerPoint and worksheet for students of GCSE physics or combined science on specific latent heat.
The PowerPoint provides definitions of the two types of specific latent heat (specific latent heat of fusion and specific latent heat of vaporisation), along with the formula E = m x L. Students use the formula to calculate the amount of energy in joules needed to effect a change of state (to melt ice and vaporise water, among other substances) according to the mass of the substance and the temperature. They also practise converting standard form to ordinary numbers.
They then carry out an experiment on the latent heat of fusion of ice, interpret heating and cooling curves for water, and answer plenary questions relating specific latent heat to the particle model to check their understanding.
Answers are provided on the PowerPoint.
The example question from the PowerPoint:
How much energy is needed to melt 2 kg of ice at 0°C?
(SLH of ice = 334 000 J/kg)
E = m x L
E = 2 x 334 000
E = 668 000 J