Question

Write the steps to convert methane to ethane.

Answer 1

Methane ${\mathrm{CH}}_4$:

• Methane is a hydrocarbon.
• It is the first member of the homologous series in alkanes.
• It is the primary content of natural gas.

Ethane ${\mathrm{C}}_2{\mathrm{H}}_6$:

• Ethane is also a hydrocarbon.
• It is the second member of the homologous series of alkanes.

Conversion of methane to ethane:

Step 1: Chlorination of methane:

• When methane reacts with chlorine in the presence of light, Methyl chloride or Chloromethane and Hydrogen chloride are formed.

$$\begin{gathered} {\mathrm{CH}}_4\left(\mathrm{g}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\stackrel{\mathrm{h\nu }}{\to }{\mathrm{CH}}_3\mathrm{Cl}\left(\mathrm{g}\right)+\mathrm{HCl}\left(\mathrm{g}\right) \\ \left(\mathrm{Methane}\right)\left(\mathrm{Chlorine}\right)\left(\mathrm{Chloromethane}\right)(\mathrm{Hydrogen}\mathrm{chloride}) \end{gathered}$$

Step 2: Wurtz reaction:

• Chloromethane undergoes Wurtz reaction with sodium and dry ether as a solvent to give ethane and Sodium chloride.

$$\begin{gathered} 2{\mathrm{CH}}_3\mathrm{Cl}\left(\mathrm{g}\right)+2\mathrm{Na}\left(\mathrm{s}\right)\stackrel{\mathrm{Dry}\mathrm{ether}}{\to }{\mathrm{CH}}_3-{\mathrm{CH}}_3\left(\mathrm{g}\right)+2\mathrm{NaCl}\left(\mathrm{s}\right) \\ \left(\mathrm{Chloromethane}\right)\left(\mathrm{Sodium}\right)\left(\mathrm{Ethane}\right)(\mathrm{Sodium}\mathrm{chloride}) \end{gathered}$$