Question

Addition reactions and substitution reactions are types of organic reactions. Which type of reaction is shown by:

(i) ethane? (ii) ethene?

Answer 1

(i) Ethane undergoes substitution reaction because Ethane is an alkane and alkanes undergo substitution reaction as they are saturated hydrocarbons.

For example, the Chlorination reaction of Ethane (${\mathrm{CH}}_3-{\mathrm{CH}}_3$) is a substitution reaction of alkane. The reaction is given below:

$\underset{\mathrm{Ethane}}{{\mathrm{CH}}_3-{\mathrm{CH}}_3\left(\mathrm{g}\right)}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Chloroethane}}{{\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Cl}\left(\mathrm{g}\right)}+\underset{\mathrm{Hydrochloric}\mathrm{acid}}{\mathrm{HCl}\left(\mathrm{g}\right)}$

(ii) Ethene undergoes addition reactions because they contain $\mathrm{C}=\mathrm{C}$ i.e. unsaturated hydrocarbons and unsaturated hydrocarbons undergo addition reaction.

For example, Ethene (${\mathrm{CH}}_2={\mathrm{CH}}_2$) when reacts with Water, forms Ethanol (${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}$). The reaction is given below:

$\underset{\mathrm{Ethene}}{{\mathrm{CH}}_2={\mathrm{CH}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\to \underset{\mathrm{Ethanol}}{{\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{OH}\left(\mathrm{l}\right)}$