Question

A researcher at a chemical company was asked to prepare several binary mixtures of liquids for a distillation demo but he forgot to label the composition. He then took 10 mL of the mixture he prepared and ran a fractional distillation on the mixture. Given below is the data he obtained from the distillation. Plot the data as volume (X) vs. Temperature (Y) and determine the composition and identity of the two liquids in the mixture. Explain why he did not need to collect more than 5 mL of distillate. The following liquids are the possible liquids used for making the mixture: water, aetone, dichloromethane, diethyl ether, etheyl acetate, methanol and ethanol

Vol(ml) Temperature (celsius)

0.5 75.0

1.0 75.5

1.5 76.0

2.0 77.0

2.5 77.0

3.0 77.0

3.5 98.5

4.0 99.5

4.5 99.5

5.0 99.5

Answer 1

Fractional distillation of a mixture of liquids is performed in this experiment

Looking at the data collected above,

The first fraction begins collection at 75 oC. The fraction is collected uptil temperature rises to 77 oC. After this the temperatures steepily increases to 99 oC (average). Looking at the boiling points of the pure liquids, we can conclude that this is a mixture of ethanol and water. First fraction collected is ethanol and the second fraction collected will be water at close to 100 oC.