Q1. What is the chemical formula of the 2-naphthol aniline dye?
Answer: The chemical formula of the 2-naphthol aniline dye is C16H12N2O.
Q2. What is the colour of the 2-naphthol aniline dye?
Answer: The colour of the 2-naphthol aniline dye is scarlet red.
Q3. What is the colour of pure aniline?
Answer: The shade of pure aniline star yellow. However, on exposing it to air and light, it turns red-brown.
Q4. What are the applications of azo dye?
Answer: Azo dyes are predominantly used in textile, paper manufacturing and printing units. They work as an artificial colourant.
Q5. What is the diazotization reaction?
Answer: Diazotization reaction refers to the organic reaction class that implicates the reaction of primary aromatic amines with nitrous acid to form diazonium salt. It occurs at a low temperature (between 0 – 5° C).
Q6. What is a coupling reaction?
Answer: Coupling reaction refers to the organic reaction class that implicates the joining of two chemical species together with the help of a metal catalyst.
Example of coupling reaction:
Q7. Which of the following compounds on diazotisation followed by coupling with beta-naphthol will form an azo dye?
- p-Toluidine
- N-Methylaniline
- Benzylamine
Answer: p-Toluidine on diazotisation and coupling with beta-naphthol will form an azo dye as it is a primary amine.
Q8. Draw the structure of the 2-naphthol aniline dye?
Answer: 
Q9. What is an acetylating agent? Give an example.
Answer: A reagent that bonds an acetyl group onto an organic molecule is called an acetylating agent. Example: Acetic anhydride and acetyl chloride.
Q10. What is a nitrating mixture?
Answer: A nitrating mixture is the solution of concentrated nitric acid and sulphuric acid.
Q11. How can we synthesise 2-naphthol aniline dye?
Answer: 
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