Question

1. A student carried out a simple distillation on a compound known to boil at 124°C and reported an observed boiling point of 116°-117°C. TLC comparison of the product showed that the compound was pure, and a calibration of the thermometer indicated that it was accurate. What procedural error might the student have made in setting up the distillation apparatus? 2. Which method is better for purifying a mixture of two liquids that boil at nearly the same temperature: simple distillation of fractional distillation? Explain your answer (Hint: your answer should explain the term "theoretical plates" and how they apply in this situation)

Answer 1

Question 1.

Boiling chips are usually placed in the distillation mother flask in order to avoid the bumping of the compound to be distilled.

During the distillation set up, the student might not add the boiling chips in the mother flask, due to this procedural error the student had reported an observed boiling point of 116-117 ^oC.