Pre-Lab Questions for Integrated Alkene-Distillation Lab – Part 1

In this lab you will separate a mixture of organic liquids by one of two methods: simple or fractional distillation. Your partner group will do the alternate method. In theory, which method should give the better separation? Briefly explain why.

A mixture of 10 mL of isoamyl acetate (MW=130.2 g/mol and density=0.88 g/mL) and 15 mL of methyl benzoate (MW=136.2 g/mol and density=1.09 g/mL) is distilled. Calculate the mole percent for each component.

Use the mole %’s from question 2 and the figure below to answer the following questions.

  1. What is the initial boiling point of this liquid mixture?
  2. What is the composition of the vapor in equilibrium with the initial liquid?
  3. What is the composition of the initial condensate (the condensate which forms from condensation of the vapor in equilibrium with the initial liquid)?
  • The distillation curves, one simple and one fractional, from a mixture of liquids is shown below.
  • a) Which curve, solid or dashed line, is the simple distillation? Which is fractional? How could you distinguish between them?
  • b) The possible liquids being distilled are in the table below. What are the actual identities of the two liquids?

Liquid Boiling point (degrees C)

2-methyl propane 27.8

butane 30.2

pentane 36.1

hexane 69

cyclohexane 80.8