Question

Write short note on –

i) Ozonolysis of ethylene

ii) Dehydration of ethyl alcohol​

Answer 1

Answer:

Alcohol upon reaction with protic acids tends to lose a molecule of water to form alkenes. These reactions are known as dehydrogenation or dehydration of alcohols.

It is an example of an elimination reaction. Its rate varies for primary, secondary and tertiary alcohols. This variation of rate can be attributed to the stability of carbocation generated. Since the carbocation is most stable in the case of tertiary alcohols, the rate of dehydration is highest for tertiary alcohols in comparison to secondary and primary alcohols.

Dehydrogenation is the removal of hydrogen from the feedstock, such as the treatment of paraffin for the production of olefin. The degree of dehydrogenation during thermal cracking of petroleum varies with the starting material and operating conditions, but due to its practical significance, methods have been found to increase the level of dehydrogenation and, in some cases, to make it almost the only reaction.