Question

Q1: List three variables you could change to improve the effectiveness of the fractional distillation to separating the ethanol from water?

Q2: Why is 200 proof ethanol not food grade while 190 proof one is?

Answer 1

Q1. Fractional Distillation is successful only when there is a considerable difference in the boiling points of the liquids to be seperated. Though there is not much difference between the boiling points of ethanol (78 ^oC) and water (100 ^oC) the efficiency of fractional distillation can be increased using the following protocols:

1. The heating temperature should be maintained below the boiling point of ethanol.
2. The column packing should be done properly.
3. The ratio of condensed vapor returning to thecolumn to the condensed vapor taken off as product is called the setup's reflux ratio. The reflux ratio should be high enough to carry out effective distillation.

Q2. 190 proof Alcohol contains 95 % ethanol and 5% water. This alcohol can be used as food grade alcohol.

        200 proof Alcohol contains 100 % alcohol and thus can cause dehydration in physiological system by exosmosis of living cells. Therefore, 200 proof ethanol is not suitable for food grade.