Question

Write the formula of the chain isomers of Butane and name them.

Answer 1

• Butane is an alkane with $\mathbf{4}$ Carbon atoms so the molecular formula is ${\mathbf{C}}_{\mathbf{4}}{\mathbf{H}}_{\mathbf{10}}$.
• Butane has two isomers; n-butane and isobutane.
• There are $\mathbf{4}$ Carbon atoms in the given molecular formula.
• They can either arrange in a straight chain of four carbon atoms or they can form a chain of $\mathbf{3}$ Carbon atoms with $\mathbf{1}$ side chain.
• n-Butane :

$$\begin{gathered} {\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_3 \\ \mathrm{n}-\mathrm{Butane}\left({\mathrm{C}}_4{\mathrm{H}}_{10}\right) \\ \mathrm{or} \\ \mathrm{Butane} \\ (\mathrm{Straight}\mathrm{chain}) \end{gathered}$$ $$\begin{gathered} {\mathrm{CH}}_3-\mathrm{CH}-{\mathrm{CH}}_3 \\ | \\ {\mathrm{CH}}_3 \\ \mathrm{Iso}-\mathrm{Butane}({\mathrm{C}}_4{\mathrm{H}}_{10}) \\ \mathrm{or} \\ 2-\mathrm{Methyl}\mathrm{Propane} \\ (\mathrm{Branched}\mathrm{chain}) \end{gathered}$$