Question

How many compounds given below belong to the same homologous series?
${\text{CH}}_2{\text{O}}_2,{\text{C}}_3{\text{H}}_8\text{O},{\text{C}}_2{\text{H}}_4{\text{O}}_2,{\text{C}}_2{\text{H}}_6,{\text{C}}_3{\text{H}}_6{\text{O}}_2,{\text{C}}_4{\text{H}}_8{\text{O}}_2$

• A. four
• B. five
• C. three
• D. two

Answer 1

The correct option is A four

Homologous series is a series of compounds having the same functional group and the successive members of which differ by -${\text{CH}}_2$ group. In the given list, following compounds belong to the same homologous series:

$\underset{\left({\text{CH}}_2{\text{O}}_2\right)}{\text{HCOOH}},\underset{\left({\text{C}}_2{\text{H}}_4{\text{O}}_2\right)}{{\text{CH}}_3\text{COOH}},\underset{\left({\text{C}}_3{\text{H}}_6{\text{O}}_2\right)}{{\text{CH}}_3{\text{CH}}_2\text{COOH}},\underset{\left({\text{C}}_4{\text{H}}_8{\text{O}}_2\right)}{{\text{CH}}_3{\text{CH}}_2{\text{CH}}_2\text{COOH}}$

Hence, the answer is four.