Read the Passage carefully and answer the Questions.

Carbonyl compounds such as aldehydes, ketones, and carboxylic acids play an important role in the biochemical process of plants and animal kingdom. Many aldehydes and ketones find applications in dye, perfumery and other industries. The carbonyl carbon atom is $sp^2$-hybridized forming three sigma and one pi-bond with oxygen. C-O bonds are polar bond due to high electronegativity of oxygen than carbon. Hence the carbonyl carbon behaves as an electrophilic center and oxygen as a nucleophilic centre. Primary and secondary alcohols yield aldehydes and ketones respectively upon oxidation with variety of oxidizing agents. The boiling points of aldehydes and ketones differ from hydrocarbons and ethers. Aldehydes and ketones undergo nucleophilic addition reaction due to presence of electrophilic carbonyl carbon. Nucleophile and a proton add across the carbon oxygen double bond.

The starting compound Y in the following reaction is

$RCH_2OH$

The correct answer is Option (3) → $RCH_2OH$ **

The reaction sequence provided is:

$Y\overset{\text{oxidation}}{\longrightarrow}​\text{Aldehyde}\overset{\text{oxidation}}{\longrightarrow}​\text{​Carboxylic acid}$

This sequence shows that compound Y undergoes oxidation to form an aldehyde, and the aldehyde is then further oxidized to form a carboxylic acid.

Analysis of the Oxidation Pathway

Oxidation of organic compounds typically follows this hierarchy:

1. $\text{Primary Alcohol} (R−CH_2​OH) \overset{\text{oxidation}}{\longrightarrow}​\text{​ Aldehyde (R−CHO)}$
2. $\text{Aldehyde (R−CHO)} \overset{\text{oxidation}}{\longrightarrow}​\text{​ Carboxylic acid (R−COOH)}$

• Step 1: The final product is a Carboxylic acid. Carboxylic acids are formed by the oxidation of an Aldehyde.
• Step 2: The intermediate product is an Aldehyde. Aldehydes are formed by the oxidation of a Primary alcohol.

Therefore, for the reaction to proceed as shown, Y must be a compound that oxidizes to an aldehyde. This means Y is a Primary Alcohol.

Conclusion

The starting compound Y is a Primary Alcohol $(R−CH_2​OH)$.