Question

Number of chain isomers of $C_6{H}_{14}$ is:

• A. 3
• B. 4
• C. 5
• D. 6

Answer 1

The correct option is C

5

There are total 5 chain isomers.
Let's try to draw isomers (chain) of $C_6{H}_{14}$

$C{H}_3-C{H}_2-C{H}_2-C{H}_2-C{H}_2-C{H}_3$

n-Hexane

Now, with one substituent

$C{H}_3-\stackrel{C{H}_3}{\stackrel{|}{CH}}-C{H}_2-C{H}_3$

(2 - Methyl pentane)

Now, substituent at different carbon

$C{H}_3-C{H}_2-\underset{\stackrel{|}{C{H}_3}}{CH}-C{H}_2-C{H}_3$

(3-Methyl pentane)

$\to$ Now with two substituent

$C{H}_3-\stackrel{C{H}_3}{\stackrel{|}{CH}}-\underset{C{H}_3}{\underset{|}{CH}}-C{H}_3$

(2, 3 - dimethyl butane)

$\to$ Now at same position

$C{H}_3-\stackrel{C{H}_3}{\stackrel{|}{\underset{C{H}_3}{\underset{|}{CH}}}}-C{H}_2-C{H}_3$

(2, 2 - Dimethyl butane)

Therefore, there are total 5 chain isomers.