Question

A liquid mixture containing 28 mol% ethanol and 72 mol% 1-propanol is placed in an open vessel and heated slowly. If heat is supplied continuously after the mixture begins to boil, how will the liquid temperature change with time? a Txy diagram was not provided. The answer choices were: Not change, increase, or decrease.

Answer 1

As we know ethanol and 1- propanol belongs to the homologous series of alcohol and ethanol precedes propanol so, it will be more volatile than propanol. So, when we keep on heating the liquid mixture then the more volatile component escape with the passes of time and the composition of propanol increases.

And with the increase in the composition of propanol the bubble point of the liquid is also increase and at last only propanol is left with the higher boiling point than ethanol.

So, the liquid temperature increases.