Question

The first member of the alcohol series is:
(A) $HCOH$
(B) $C{{H}_{3}}OH$
(C) $C{{H}_{2}}OH$
(D) $C{{H}_{3}}C{{H}_{2}}OH$

Answer 1

All the organic compounds based on their structure and chemical properties have been divided into different families or groups that exhibit gradation in physical and chemical properties. Following that, a sequence of compounds with the same functional groups and similar properties forms a series of branched or unbranched homologous series.

Complete step by step solution:
-An organic compound with a hydroxyl (OH) functional group on an aliphatic carbon atom is known as alcohol. The general formula of alcohols R-OH which represents alcohol with –OH functional group of all alcohols.
-The hydroxyl group of alcohol structurally similar organic compounds with the same hydroxyl group and two adjacent members of which differ by $-C{{H}_{2}}$ group forms homologous series. The individual member of this series is called homologous and this phenomenon is named Homology.
-The general formula of homologous series of alcohols is ${{C}_{n}}{{H}_{2n+1}}OH$, where n is the number of carbon atoms in the series. This general formula for alcohols with saturated hydrocarbons.
-Alcohols are frequently commonly named as alcohol for the first four carbon atoms, which is the name of the alkyl group followed by alcohol.
-According to IUPAC nomenclature, alcohols are named after the parent alkane name as –ol.

Name of the member	Molecular formula	IUPAC name	Structural formula
Methyl alcohol	$C{{H}_{3}}OH$	Methanol	${{H}_{3}}C-OH$
Ethyl alcohol	${{C}_{2}}{{H}_{5}}OH$	Ethanol	$C{{H}_{3}}-C{{H}_{2}}-OH$
Propyl alcohol	${{C}_{3}}{{H}_{7}}OH$	Propanol	$C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-OH$
Butyl alcohol	${{C}_{4}}{{H}_{9}}OH$	Butanol	$C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{2}}-OH$

Hence, Methanol $C{{H}_{3}}OH$is the first member of the alcohol series.

So, the correct answer is option B.

Note: Methanol is also called methyl alcohol, wood alcohol, or wood spirit, and methanol and ethyl alcohol are the first and two members in the homologous series of alcohols. As the molecular mass increases in homologous series, physical properties gradation will be observed. But the chemical properties depend on the hydroxyl functional group in the homologous series of alcohols.