Question

Consider the following organic compounds:

(i) \[\begin{array}{cc} \ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\ |\phantom{....}|\phantom{....}|\\ \ce{H - C - C - C = O}\\ |\phantom{....}|\phantom{.....}\\ \ce{H}\phantom{....}\ce{H}\phantom{.....} \end{array}\]

(ii) \[\begin{array}{cc} \phantom{....}\ce{H}\phantom{...}\ce{H}\phantom{....}\\ \phantom{....}|\phantom{....}|\phantom{....}\\ \ce{H - C - C = O}\\|\phantom{.....}\\ \ce{H}\phantom{.....}\end{array}\]

1. Name the functional group present in these compounds.
2. Write the general formula for the compounds of this functional group.
3. State the relationship between these compounds and draw the structure of any other compound having a similar functional group.

Answer 1

(a) Functional group: Aldehyde

(b) General formula: C_nH_2nO

(c) It forms the part of the homologous series of the aldehydes as these compounds differ from each other by \[\ce{- CH}\] unit.

Structure of 4^th member of this series is:

\[\begin{array}{cc}
\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\\
|\phantom{....}|\phantom{....}|\phantom{....}|\\
\ce{H - C - C - C - C = O}\\
|\phantom{....}|\phantom{....}|\phantom{.....}\\
\ce{H}\phantom{...}\ce{H}\phantom{...}\ce{H}\phantom{.....}\end{array}\]