Absolute or 100% ethanol is produced from a mixture of 95%
ethanol and 5% water using the Keyes distillation process. A third
component, benzene, is added to lower the volatility of the
alcohol. Under these conditions, the overhead product is a
constat-boiling mixture of 18.5% ethanol, 7.4% water and 74.1%
benzene. Use the following data to calculate the volume of benzene
that should be fed to the still in order to produce 250 litres of
absolute ethanol: density of 100%...