Question

What is Aldehyde ? Write the IUPAC names and formulas of the first three numbers of this series.

Answer 1

Hint:
First we should be aware of the term aldehyde and what they actually represent and as a group they are. Then we have to define their chemical nature and the chemical structure in the general aspect. That defines the kind of functional group they are in organic chemistry. Then we have to give the IUPAC nomenclature rule for the aldehydes. After that we just have to define the first 3 aldehydes and their names as per nomenclature.

Complete step by step answer:
An aldehyde is specific kind of an organic compound which is containing a functional group with the chemical formula and structure of $ - CHO$ , consisting of a carbonyl center (a carbon double-bonded to oxygen) with the carbon atom also bonded to hydrogen and to an R group. This R could be any generic alkyl or side chain.
Aldehyde series is a homologous series. The common formula that is given for the compounds of this series is $R - CHO$ where $R$ could be any chain of organic compound with carbon and hydrogen.
For the case of IUPAC nomenclature there is one rule for the naming of the aldehyde compounds, suffix 'e' is substituted by -al of relative alkane.
For the case of the first 3 members of the series :
Formaldehyde:
IUPAC Name : Methanal
Derived from the methane
The chemical formula is $HCHO$
Acetaldehyde:
IUPAC Name : Ethanal
Derived from the ethane
The chemical formula is $C{H_2}CHO$
Propanaldehyde:
IUPAC Name : Propanal
Derived from the propane
The chemical formula is ${C_2}{H_5}CHO$.


Note:
Aldehydes are a very high priority functional group. They share very properties with the ketones as they both are termed as carbonyl compounds. They often worked in groups and stayed intact in the priority series close to each other.