(i) What is a homologous series of organic compounds?

[Murali]

1. What is a homologous series of organic compounds ? State any two characteristics of a homologous series.
2. Draw the electron dot structure for propanal.

Answer:

1. A series of compounds in which the same functional group substitutes for hydrogen in a carbon chain is called homologous series.

Characteristics of homologous series:

• The molecular formulae of any two successive members of a homologous series differ by —CH2.
• There is a regular gradation in physical properties of members of a homologous series.

2.