Unknown Ketone Lab Report

The purpose of this experiment was to identify an unknown starting material. The experiment was taken place over a period of two weeks. The first week was the preparation of the Grignard reagent and the performing of the reaction with the unknown ketone and the second week was the purification and the identification of the crude product obtained from week one. The starting alkyl halide that was assigned to me was 13H and the ketone was 13K. With these, I performed the reaction. The end results were the following:

Mass of Product:
0.18 g

Boiling Point Range:
158.8°C-164.2°C

Percent Yield:
Actual: 0.18 g
Theoretical:
1-Bromopentane: 0.025 mol Acetone: 0.025 mol
Product: 2-methyl-2-heptanol: 0.025 mol x (130.23 g/mol) = 3.26 g
% Yield: (actual/theoretical) x 100 = (0.18 g/3.26 g) x 100 = 5.5%

After the IR was obtained, analyzed and compared to reference spectrums, and the boiling point was compared to the boiling points in the chart, it was concluded that the unknown product from the reaction was 2-methyl-2-heptanol. The boiling point of 2-methyl-2-heptanol is 162°C, which is between the range of the boiling point obtained

From the list of possible starting materials, it was concluded that 1-bromopentane and acetone were the starting materials because if a Grignard reaction were performed, the end product would be 2-methyl-2-heptanol. It is also possible for the alcohol product to be prepared from another combination of halides and ketones than the ones used for this experiment. For example, using methyl bromide and 2-heptanone. The Grignard reaction for these starting materials is shown