A cryogenic vial storage chamber is cooled using liquid nitrogen. During a cooling cycle, some of the liquid nitrogen absorbs thermal energy from the chamber and vaporises at its boiling point.
At the beginning of the cycle, the mass of liquid nitrogen in the chamber's reservoir is 1.85 kg.
After the cooling cycle, the mass of liquid nitrogen remaining in the reservoir has decreased to 1.53 kg.
The thermal energy absorbed by the liquid nitrogen to vaporise it during this cycle was 63 680 J63\,680\text{ J}63680 J.
Calculate the specific latent heat of vaporisation of liquid nitrogen.
Use the equation:
thermal energy for a change of state=mass×specific latent heat \text{thermal energy for a change of state} = \text{mass} \times \text{specific latent heat} thermal energy for a change of state=mass×specific latent heat36 exam-style questions on Edexcel GCSE Physics 14.2 Specific heat capacity and latent heat, covering 14.2.1 Heating, temperature and changes of state, 14.2.2 Specific heat capacity and specific latent heat, 14.2.3 Specific heat capacity calculation, 14.2.4 Specific latent heat calculation, and 14.2.5 Reducing energy transfer through thermal insulation. Each one has a worked solution and a mark scheme showing where the marks go.