Question

How can you obtain Ethene from Ethanol

Answer 1

1. Ethanol is heated at $443\mathrm{K}$ in presence of excess Sulphuric acid to obtain Ethene.
   $$\begin{gathered} {\mathbf{CH}}_{\mathbf{3}}\mathbf{-}{\mathbf{CH}}_{\mathbf{2}}\mathbf{OH}\mathbf{}\mathbf{+}\mathbf{}{\mathbf{H}}_{\mathbf{2}}{\mathbf{SO}}_{\mathbf{4}\mathbf{}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{}\mathbf{\to }\mathbf{}{\mathbf{CH}}_{\mathbf{2}}\mathbf{=}{\mathbf{CH}}_{\mathbf{2}}\mathbf{}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{}\mathbf{+}\mathbf{}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\mathbf{}\mathbf{\left(}\mathbf{l}\mathbf{\right)} \\ \mathbf{Ethanol}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{conc}\mathbf{.}\mathbf{}\mathbf{Sulphuric}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{Ethene}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{} \\ \mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{acid} \end{gathered}$$
2. During the conversion of Ethanol into Ethene in the presence of conc. Sulphuric acid, a molecule of water is lost.
3. In this reaction, conc. Sulphuric acid acts as a dehydrating agent.