A distillation column separates 10,000 kg/h of a 50 wt% benzene-50% toluene mixture. The top product contains 95% benzene and the bottom product (B) contains 96% toluene. 7000 kg/h of vapour (V) from...

A distillation column separates 10,000 kg/h of a 50 wt% benzene-50% toluene mixture. The top product contains 95% benzene and the bottom product (B) contains 96% toluene. 7000 kg/h of vapour (V) from the top of the column enters the condenser where it is totally condensed to liquid. A portion of this liquid is returned to the distillation column as reflux (R) and the remainder is withdrawn as top product (D).
a) Find the composition of vapour stream