Solution

If a gas is at temperature $80\,^{\circ}\mathrm{C}$ and pressure $5 \times 10^{-10}\,\mathrm{N\,m^{-2}}$, having $1\,\mathrm{m^{3}}$ volume, what is the number of molecules per cubic metre, where Boltzmann's constant is $1.38 \times 10^{-23}\,\mathrm{J\,K^{-1}}$.