Answer the following questions: By how many `-CH_2-` (methylene) units do the formulae and the fist two members of homologous series ofalkane, methane `(CH_4)` and ethane `(C_2H_6)` differ? Similarly, by how many `-CH_2-` Units do the neighboring members ethane `(C_2H_6)` and propane `(C_3H_8)` differ from each other?

Explanation

The first two members of homologous series of alkanes, methane `(CH_(4))` and ethane `(C_(2)H_(6))` differ by one `-CH_(2)-` unit in their formulae. Similarly, ethane `(C_(2)H_(6))` and propane `(C_(3)H_(8))` differ by one `-CH_(2)-` unit from each other.