Question

Formaldehyde is the first member of the aldehyde family is a _________ at an ordinary temperature.
(A) Solid
(B) Liquid
(C) Gas
(D) None of these

Answer 1

Hint : Chemical compounds are classified into different compounds based on the nature of the functional group they have. Carbonyl compounds are the compounds that contain the $C = O$ group. Aldehydes and ketones belong to carbonyl compounds. Formaldehyde is a first member of the aldehyde family.

Complete Step By Step Answer:
There are a huge number of chemical compounds. Based on the nature of groups present in chemical compounds, the classification was done. The chemical compounds that contain $C = O$ are called carbonyl compounds. Ketones and aldehydes belong to carbonyl compounds.
In aldehyde $C = O$ is attached to an alkyl group or a carbon that is a part of the alkyl group on one side. The other side is attached to the hydrogen atom.
Formaldehyde is a compound that belongs to aldehydes with the molecular formula of $HCHO$ , it contains two hydrogen atoms, one carbon atom and one oxygen atom.
It is the first member in the aldehydes family and exists as a gas at ordinary temperatures. Commercially, formaldehyde will be available as $40$ formalin.

Note :
The IUPAC name of formaldehyde is methanal. As it contains one carbon atom the root word will be meth and the suffix to the aldehyde group must be written as -al. Thus, the name will be methanal. As it is the derivative of formic acid. The formic acid will be obtained from the ants. The ant has a Greek name as formants. The common name is obtained like this.