Concept:
Aspirin is chemically known as Acetylsalicylic acid. It is prepared by the acetylation of salicylic acid using acetic anhydride in the presence of an acid catalyst.
• Salicylic acid contains a phenolic \((-OH)\) group.
• Acetic anhydride provides the acetyl group \((CH_3CO-)\).
• The reaction produces aspirin and acetic acid.
Step 1: Identify the product formed.
The product given in the reaction is:
\[
\text{Aspirin}
\]
Aspirin is chemically known as:
\[
\text{Acetylsalicylic acid}
\]
Hence, the reactant must be:
\[
\text{Salicylic acid}
\]
Step 2: Write the reaction involved.
\[
\text{Salicylic acid} + \text{Acetic anhydride}
\xrightarrow{H^+}
\text{Aspirin} + \text{Acetic acid}
\]
Step 3: Eliminate incorrect options.
• Acrylic acid does not form aspirin on acetylation.
• Oxalic acid is a dicarboxylic acid and is not used in aspirin synthesis.
• Phthalic acid also does not produce aspirin with acetic anhydride.
Step 4: Conclusion.
Therefore, compound \(A\) is:
\[{\text{Salicylic acid}}
\]
Final Answer: Option (C)
