A mixture of $70\%$ normal heptane and $30\%$ normal octane at $30C$ is continuously flashed distilled in a flash distillation $($equilibrium distillation$)$ operation at $1$ atmosphere pressure. If $50\%$ of the feed is vaporized, what is the composition of the vapor and liquid product if the system has a constant relative volatility of $3\mathrm{.}0$

Calculate the rate of diffusion $(mo\frac{l}{s}$ of ammonia through a stagnant hydrogen film of $0\mathrm{.}5mm$ thickness. The total pressure is $206k\frac{N}{m}2$ and temperature $55C.$ The concentrations of ammonia on either side of the film are $10\%$ and $5\%$ by volume and the diffusivity of ammonia in hydrogen is $4\mathrm{.}110-5\frac{m^2}{s}.$

Describe the process of transfer of a gas molecule to migrate from the bulk gas phase to the liquid phase as per the Two$-$film theory highlighting key points.