Question

Give the structural formula for Ethanal:
A. $C{H}_{3}CHO$
B. $C{H}_{3}C{H}_{2}O$
C. $C{H}_{2}CO$
D. HCHO

Answer 1

Hint: The aldehyde group is one of the functional groups in which the carbonyl carbon is present which is bonded with the oxygen atom by a double bond. It is also attached to one hydrogen atom and an alkyl group. The aldehyde compound is observed by the $-CHO$ group in the structure.

Complete step by step answer:
Structural formula: The structural formula of a chemical species is defined as the graphic presentation of all the atoms attached to form the compound in three-dimensional forms. In the structural formula, the bonding between the atoms is shown properly.
The structure of ethanal is shown below.

In this structure, two carbon atoms are present, therefore the parent chain is ethane. As the aldehyde functional group is present, the suffix is given by $-al$. Therefore the IUPAC name will be ethanal.
In ethanal, there are two carbons present. One is the carbonyl carbon and the other is the carbon present in the methyl group. The carbonyl carbon is attached to the oxygen by a double bond, with the hydrogen by a single bond and with the methyl group by a single bond.
Thus, the structural formula of ethanal is $C{H}_{3}CHO$.
Thus, the correct answer is option A.

Additional information: The parent chain in the aldehydic compound depends on the number of carbon atoms present in the compound. The compound ethanal is commonly known as acetaldehyde. The chemical formula of ethanal is also given as $C_2{H}_{4}O$.


Note:
There is a difference between structural formula and condensed structural formula. In condensed structural formula no chemical bonding is shown and the atoms are written in one line.