The synthesis of azo-dyes requires understanding the process, which typically involves a diazonium salt reacting with a coupling component. In this case, sulfanilic acid is first diazotized and then coupled with a nitrogen-rich compound to produce an azo dye.
Diazotization: Sulfanilic acid reacts with sodium nitrite (NaNO2) and acetic acid (CH3COOH) to yield the diazonium ion (X).
Coupling Reaction: The diazonium ion subsequently reacts with another aromatic compound to form the azo dye (Y).
The correct option depicts the formation of an azo group (-N=N-) connecting two aromatic rings, generally represented as \(Ar-N=N-Ar'\), where Ar and Ar' denote aromatic groups.
Based on the provided options, the resulting azo dye is illustrated in the following image:
Conclusion: The reaction sequence of sulfanilic acid with NaNO2 and CH3COOH, followed by coupling, generates the azo dye depicted in the correct answer image, aligning with the standard azo-dye structure.
Consequently, the correct answer corresponds to the final option presented above.
