Chemistry of Dyes and Pigments paper (WPE 305) from the 2023 Level-3 Term-I finals, BUTEX affiliated colleges. Questions address dye classification by structure, azo synthesis and tautomerism, dichlorotriazinyl reactive systems, disperse dyeing methods, and biomedical dyes.
Level-3 Term-I, Final Exám-2023
Subject: Chemistry of Dyes and Pigments (Code: WPE 305)
Time: 3.0 Hrs. Full Marks: 72
(Use separate answer script for Part: A and Part: B)
(All parts of a question must be answered consecutively)
Part: A
(Answer any three questions)
1. (a) Classify dyes and pigments based on chemical structure with example.
(b) Write about complementary color relationship showing their wavelengths.
(c) State the requirements for a colorant to be a true dye.
[5+4+3 = 12]
2. (a) Why azo dyes and pigments are so called?
(b) State the synthesis strategies of azo dyes and pigments.
(c) Explain tautomerism of azo dyes with example.