(a)[3]
The first law of thermodynamics can be written as $\Delta U = q + w$. Explain what the symbols $\Delta U$, $q$ and $w$ mean in this equation.
(b(i))[3]
State the meaning of specific latent heat.
(b(ii))[3]
Use the first law of thermodynamics to explain why the specific latent heat of vaporisation is greater than the specific latent heat of fusion for a particular substance.