Four compounds $($Aniline $(C_6{H}_{5}N{H}_2)$; benzene

$(C_6{H}_6),$ toluene $(C_7{H}_8),$ and xylene $\{$:$(C_8{H}_{10}))$ are

mixed in a mixer. The volumetric flow rate for

Aniline $=3m\frac{L}{s},$ benzene $=7\frac{L}{h},$ toluene $=0\mathrm{.}05$

$\frac{m^3}{h},$ and xylene $=8c\frac{m^3}{s}.$ Meanwhile the

specific gravity $($or density in g$/$cm ${?}^3)$ of each

component is $1\mathrm{.}02,0\mathrm{.}879,0\mathrm{.}866,$ and $0\mathrm{.}865,$

respectively.

$\{$:$1)$ What is the mass fraction of each compound?

$2)$ Calculate the average molecular weight of the

product $($after mixing$).$