A stream of $2$ kmol$/$h of a mixture of acetonitrile $($A$)$ and toluene $($T$),$ of mole fraction

of acetonitrile $0\mathrm{.}25,$ is heated in a heat exchanger $($Q$)$ and then subjected to

a partial vaporization. The vapor $($nV$)$ and liquid $($nL$)$ compositions are

xV$=0\mathrm{.}401$ and xL$=0\mathrm{.}096$ in mole fractions of acetonitrile. The current nL coming out of the

vaporizer $($T$)$ is introduced into a distillation column $($R$)$ in order to obtain a

product nW with an xW $=0\mathrm{.}02.$ The nV current leaving the vaporization is condensed

completely in the exchanger C and already in liquid form joins the distillate nD from R

to give rise to a product stream P with an xPA$=0\mathrm{.}435.$ Calculate the value of the

distillate stream nD expressed in kmol$/$h leaving R$.$