The diagram illustrates the apparatus used to determine the relative molecular mass of a volatile liquid. When $0.10\,\text{g}$ of a volatile liquid is placed in the syringe, the whole sample vaporises and the volume rises by $85\,\text{cm}^3$. The heater keeps the temperature at $400\,\text{K}$, and the investigation is performed at a pressure of $101\,300\,\text{Pa}$. If the vapour of the volatile liquid acts as an ideal gas, which expression should be used to calculate the relative molecular mass of the liquid?
- A$M_r = \dfrac{85 \times 101300}{0.10 \times 8.31 \times 400}$
- B$M_r = \dfrac{85 \times 101.3}{0.10 \times 8.31 \times 400}$
- C$M_r = \dfrac{0.10 \times 8.31 \times 400}{85 \times 10^{-6} \times 101300}$
- D$M_r = \dfrac{0.10 \times 8.31 \times 400}{85 \times 10^{-6} \times 101.3}$