Question

Pre-Lab Question: A student carried out a simple distillation on a compound known to boil at 24oC and reported an observed boiling point of 116oC. The compound was shown to be pure and the thermometer was calibrated properly. What procedural error might the student have made in setting up the distillation apparatus? ​

Answer 1

Its impossible are you sure is it 24oC or 124oC !!!!!!!. I assume it is 124oC.

The only thing I can think of is that the thermometer was not correctly placed in the neck of the distillation flask. If the bulb of the thermometer was placed above the distilling flask side arm, the temperature at that location probably is less than the boiling point.

OR

What the student has most likely done is incorrectly positioned the thermometer. The position of the bulb is critical for obtaining an accurate reading of the temperature of the vapour at the point where the vapour just reaches the side-arm that attaches to the condenser. Not low enough, and you will not be measuring the temperature of a vapour that is in equilibrium with the distilling mixture. That explains the depressed boiling range.