Question

How will you convert ethane to ethene?

Answer 1

Ethane to ethene:

Step 1 Formation of Ethyl chloride

Ethane reacts with chlorine in presence of sunlight, one hydrogen gets substituted by Chlorine to give ethyl chloride.

$\underset{\mathrm{Ethane}}{{\mathrm{CH}}_3-{\mathrm{CH}}_3}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2}\stackrel{\mathrm{h\nu }}{\to }\underset{\mathrm{Ethyl}\mathrm{chloride}}{{\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Cl}}+\underset{\mathrm{Hydrochloric}\mathrm{acid}}{\mathrm{HCl}}$

Step 2 Formation of ethene:

Ethyl chloride on reaction with the alcoholic $\mathrm{KOH}$ , one Chlorine atom and one Hydrogen atom from the other Carbon atom gets removed.

Then a double bond is also formed between these two Carbon atoms to give Ethene.

$\underset{\mathrm{Ethyl}\mathrm{chloride}}{{\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Cl}}+\underset{\mathrm{Potassium}\mathrm{hydroxide}}{\mathrm{KOH}}\to \underset{\mathrm{Ethene}}{{\mathrm{CH}}_2={\mathrm{CH}}_2}+\underset{\mathrm{Potassium}\mathrm{chloride}}{\mathrm{KCl}}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}}$