MCQ Detailed View

The conversion of ethanol (C₂H₅OH) into ethanoic acid (CH₃COOH) is a classic example of an oxidation reaction in organic chemistry. Ethanol is a primary alcohol, and when it undergoes oxidation, it is first converted into an aldehyde (acetaldehyde, CH₃CHO), and then further oxidized to a carboxylic acid, ethanoic acid.

The reaction is typically carried out using strong oxidizing agents such as acidified potassium dichromate (K₂Cr₂O₇ in H₂SO₄) or potassium permanganate (KMnO₄). In the laboratory, when ethanol is treated with these oxidizing agents under reflux conditions, the orange color of dichromate turns green due to the formation of Cr³⁺ ions, confirming oxidation.

The process can be summarized in two steps:

1. 
   

   Ethanol → Acetaldehyde (partial oxidation)

   
   


2. 
   

   Acetaldehyde → Ethanoic acid (further oxidation)

   
   

Overall, the reaction pathway is:

C₂H₅OH → CH₃CHO → CH₃COOH

This transformation is an important example of how alcohols can be converted into carboxylic acids. The reaction is not reduction, because reduction involves gain of hydrogen or loss of oxygen. It is also not neutralization, since no acid-base reaction occurs. It is certainly not hydrogenation, which involves the addition of hydrogen to unsaturated compounds.

The oxidation of ethanol has great industrial and biological significance. In industry, this reaction is a step in the manufacture of acetic acid, which is used in vinegar, plastics, synthetic fibers, and pharmaceuticals. In biological systems, the liver also oxidizes ethanol into acetic acid through enzyme-mediated pathways, though using a different biochemical route.

Thus, ethanol is converted into ethanoic acid by the chemical process of oxidation, making oxidation the correct answer.