$($Drawing the feed line for different feed conditions$)$ A mixture of benzene and toluene containing $58$mole$\%$ benzene is to be separated in a continuous column operating at $1$atm total pressure. Draw the feed line for the following feed conditions: $($a$)$ saturated liquid, $($b$)$ saturated vapour, $($c$)65$mass$\%$ vapour, $($d$)$ vapour at $120C,$ and $($e$)$ liquid at $50C.$

The other relevant data are given as follows: Benzene: average specific heat of liquid $=146\mathrm{.}5k\frac{J}{k}$mol$*K,$ of vapour $=97\mathrm{.}6k\frac{J}{k}$mol$*K$; heat of vaporization $=30,770k\frac{J}{k}$mol. Toluene: average specific heat of liquid $=170k\frac{J}{k}$mol$*K,$ of vapour $=124\mathrm{.}3k\frac{J}{k}$mol$*K$; heat of vaporization $=32,120k\frac{J}{k}$mol.