Question

Questions for an Hydrogenation of a Fatty Acid Methy Ester experiment using Pd/C catalyst, methanol, and methyl oleate.

1. Why is the catalyst needed for hydrogenation, yet not for bromination?

2. Explain how you isolate the final product in the hyrogenation of a fatty acid methyl ester experiment. (Heating, crystallization, filtration)

3. Explain the various aspects of the reaction setup. Why were the steps in the procedure done in the order that they were?

Answer 1

Q.1: This can be explained from H-H and Br-Br bond energies whch are respectively 435 kJ/mol and 192 kJ/mol.

Due to very high H-H bond energy, the hydrogination reaction is very slow and requires high temperature to achieve activation energy. Hence hydrogination requires a suitable catalyst that can reduce the activation energy and increase the rate of th

However due to low Br-Br bond energy, the activation energy for bromination is low. Hence it doesn't require a catalyst to proceed the reaction.

Q.2: The catalyst can be removed through filtration. Excess methanol can be removed through heating or evaporation.