Define the term specific latent heat.
A dish holding $7.2 \times 10^{-5}\,\text{m}^3$ of a substance is placed on a laboratory bench. At the start, the substance is a liquid with density $710\,\text{kg m}^{-3}$. Atmospheric pressure is $1.0 \times 10^{5}\,\text{Pa}$. The liquid is heated at its boiling point until it all becomes vapour. During this process, the increase in internal energy of the substance is $17.6\,\text{kJ}$. The vapour finishes with a volume of $0.017\,\text{m}^3$.
Show that the magnitude of the work done on the substance as it vaporises is $1.7\,\text{kJ}$.
Use the information in (b)(i) to find the thermal energy $Q$, in kJ, that must be supplied to the substance for it to vaporise.
Use your answer in (b)(ii) to find a value for the specific latent heat of vaporisation $L_v$, in $\text{kJ kg}^{-1}$, of the substance.
The substance in (b) has a specific latent heat of fusion $L_F$. Suggest and explain whether $L_F$ is likely to be less than, the same as, or greater than the value in (b)(iii).