According of Reference Table H, what is the boiling point of ethanol acid at 80 kPa?
1) 111 Celsius
2) 28 Celsius
3) 125 Celsius
4) 100 Celsius
The Correct Answer and Explanation is :
At a reduced pressure of 80 kPa, the boiling point of acetic acid (ethanoic acid) is approximately 111°C. This is because the boiling point of a liquid decreases as atmospheric pressure decreases. At standard atmospheric pressure (101.3 kPa), acetic acid boils at about 118.1°C. Reducing the pressure to 80 kPa lowers the boiling point to around 111°C.
This phenomenon occurs because boiling happens when the vapor pressure of the liquid equals the external pressure. Lowering the external pressure allows the liquid’s vapor pressure to reach equilibrium at a lower temperature, thus reducing the boiling point.
Therefore, among the provided options:
1) 111°C
2) 28°C
3) 125°C
4) 100°C
Option 1, 111°C, is the correct answer.