Question

Assertion
The conversion of ethanol to ethanoic acid is an oxidation reaction.
Reason
The molecule of ethanol contains six hydrogen atoms while that of ethanoic acid contains four hydrogen atoms since oxidation involves removal of hydrogen. Therefore, conversion of ethanol to ethanoic acid is an oxidation reaction.
A. Both assertion and reason are correct and reason is the correct explanation for assertion.
B. Both assertion and reason are correct but reason is not the correct explanation for assertion.
C. Assertion is correct but reason is incorrect.
D. Both assertion and reason are incorrect.

Answer 1

Oxidation is described as addition of oxygen to the substrate or removal of hydrogen. In oxidation of alcohols the hydrogen is removed from the carbon bearing the ${\text{ - OH}}$ group and from the oxygen atom.

Complete step by step answer:
Oxidation is a process by which carbon atoms gain bonds to more electronegative elements, most commonly oxygen. Oxidation reactions are those in which the central carbon of a functional group is transformed into a more highly oxidized form. The maximum oxidation state that a carbon can attain decreases gradually as the number of bonds to other carbon increases. Thus, the maximum oxidation state of carbon that is bonded to other carbon is the carboxylic acid stage.
Primary alcohols are initially oxidised to aldehydes. The reaction however doesn’t stop at the aldehyde and the aldehyde formed is further oxidized to carboxylic acid.
Thus, the molecule ethanol which has six hydrogen atoms whereas ethanoic acid contains four hydrogen atoms and the conversion of ethanol to ethanoic acid involves removal of hydrogen thus it is an oxidation reaction.

Hence, the answer is option A.

Additional information:
The reactions involving the transfer of electrons from one species to another are called oxidation-reduction or redox reaction. Reduction is a process by which a carbon atom gains bonds to less electronegative elements, most commonly hydrogen or the addition of hydrogen to a double bond and the replacement of an atom or a group by hydrogen is called reduction reactions.

Note: The most commonly used oxidising agents are ${{\text{O}}_{{\text{2, }}}}{{\text{O}}_{{\text{3,}}}}{\text{ Mn}}{{\text{O}}_{\text{2}}}{\text{, Cr}}{{\text{O}}_{\text{3}}}{\text{, Os}}{{\text{O}}_{\text{4}}}$ etc. The oxidation reactions are further classified into various types depending on the type of bond cleavage as substitution of hydrogen to oxygen, addition of oxygen, elimination of hydrogen, oxidative cleavage, oxidative coupling, addition of other electronegative atoms and substitution of other electronegative atoms.