Question

Ethanol has a boiling point of 78°C. Water has a boiling point of 100°C. If a mixture of ethanol and water is distilled ____.

the ethanol will evaporate first
the water will evaporate first
both liquids will evaporate at the same time

Answer 1

The correct answer is: "The ethanol will evaporate first"

Step-by-step explanation:

Fractional distillation is a physical process used to separate various liquid mixtures in which liquids have nearby boiling points. In other words, both compounds are volatile (volatility is the property of evaporating, moving from the liquid to the gaseous state).

The process consists in heating the liquid mixture to be separated. Upon reaching the boiling temperature of the most volatile component (with a lower boiling point) a vapor phase will be formed, which will mostly contain this substance at the beginning.

Then, as the temperature continues to rise and as time goes by, multiple evaporation and condensation cycles continuously occur (each cycle is known as the "theoretical plate"), until the lower boiling constituent first emerges, that is, It will separate.

In this case, since ethanol is the element with the lowest boiling point, it will be the most volatile and will separate first. So the correct answer is: "The ethanol will evaporate first"