Question

You will use a simple distillation to isolate the

product mixture in the dehydration reaction. Then you will separate the water

from the alkene products by extraction using ether as your extraction solvent, dry

the ether, and evaporate the ether to prepare your alkene mixture for analysis.

Would it be useful at this point to do a second simple distillation to try to isolate

each of the alkene products before analysis so that you can analyze each product

separately rather than analyzing a mixture of alkenes? Why or why not? Explain.

Answer 1

When we prepare Alkene by dehydration method then reaction through ionic mechanism and general intermidiate is carbocation. Since carbocation is reactive intermediate it polymeric alkene product during the reaction. Now to avoid the polymeric alkene it is better to one simple distilation. More over in dehydration reaction chance of isomerisation of alkene is very high like cis and Trans as well positional isomer that can also be separated during distilation. This simple distilation ineed help in next step i.e column chromatoghraphy step.