An essential oil is to be purified by batch distillation. The initial batch is $10$kmol in size and

contains $25$mol$\%$ of the essential oil. A distillate purity of $75$mol$\%$ is required. Assuming a

constant relative volatility of $16\mathrm{.}5,$ how many kilomoles of distillate are produced and what is

the yield of essential oil?

Ans: $2\mathrm{.}57$kmol of distillate, $77\%$ yield