Question

Which among the following is the eighth member of the homologous series of aldehydes?

• A. $C_7{H}_{17}CHO$
• B. $C_8{H}_{15}COOH$
• C. $C_7{H}_{15}CHO$
• D. $C_5{H}_{11}CHO$

Answer 1

The correct option is C $C_7{H}_{15}CHO$

• The general formula of the homologous series of aldehydes is $C_n{H}_{2n+1}CHO$.
• With n=0 we get the first member of the homologous series of aldehydes, i.e., HCHO.
• So, in the eighth member of the homologous series of aldehydes, n=7 .
• In that $C_n{H}_{2n+1}CHO$= $C_7{H}_{15}CHO$
• $C_7{H}_{15}CHO$ is the eighth member of the homologous series of aldehyde.
• The correct option is D.