$($ii$)$ The diffusivity of $CCl4$ in air is determined by observing the steady state evaporation of CCl$4$ in a tube of $1cm$ diameter exposed to air. The $CCl4$ liquid level is $10cm$ below the top level of the tube. The system is held at $25C$ and $1$ bar pressure. The saturation pressure of $CCl4$ at $25C$ is $14\mathrm{.}76$kPa. If it is observed that the rate of evaporation of $CCl4$ is $0\mathrm{.}1k\frac{g}{?}$ hour determine the diffusivity of CC$14$ into air.