Question

Number of constitutional isomer of the formula $C_5{H}_{11}Br$ is

• A. 4
• B. 8
• C. 7
• D. 6

Answer 1

The correct option is B

8

Constitutional isomers are structural isomers

8 structural isomers are possible.

1)$\stackrel{5}{C}{H}_2\stackrel{4}{C}{H}_2\stackrel{3}{C}{H}_2\stackrel{2}{C}{H}_2\stackrel{1}{C}{H}_{2}Br$

1-bromo pentane

(2)$C{H}_{3}C{H}_{2}C{H}_2-\stackrel{Br}{\stackrel{|}{CH}}-C{H}_3$

2-bromo pentane

3) $C{H}_3-C{H}_2-\underset{Br}{\underset{|}{CH}}-C{H}_2-C{H}_3$

3-bromo pentane

(4) $\stackrel{1}{C}{H}_3-\underset{C{H}_3}{\underset{|}{\stackrel{Br}{\stackrel{2}{\stackrel{|}{C}}}}}-\stackrel{3}{C}{H}_2\stackrel{4}{C}{H}_3$

2-bromo-2-methylbutane

(5) $\underset{Br}{\underset{|}{\stackrel{1}{C{H}_2}}}-\underset{C{H}_3}{\underset{|}{\stackrel{2}{CH}}}-\stackrel{3}{C}{H}_2-\stackrel{4}{C}{H}_3$

1-bromo-2-methylebutane

(6) $\underset{4}{C}{H}_3-\underset{C{h}_3}{\underset{3}{\underset{|}{CH}}}-\underset{2}{\stackrel{Br}{\stackrel{|}{CH}}}-\underset{1}{C}{H}_3$

2-bromo-3-methylbutane

(7) $\stackrel{4}{C}{H}_3-\underset{C{H}_3}{\underset{|}{\stackrel{3}{CH}}}-\stackrel{2}{C}{H}_2-\stackrel{1}{C}{H}_{2}Br$

1-bromo-3-methylbutane

(8) $C{H}_3-\underset{3C{H}_3}{\underset{|}{\stackrel{1C{H}_{2}Br}{\stackrel{|}{C}}}}-C{H}_3$

1-bromo-2,2-dimethylpropane