In the following reactions, P, Q, R, and S are the major products.
(see structures for reaction schemes)
The correct statement (s) about P,Q,R, and S is (are)
(A)P and Q are monomers of polymers dacron and glyptal, respectively.
(B)P, Q, and R are dicarboxylic acids.
(C)Compounds Q and R are the same.✓ Correct
(D)R does not undergo aldol condensation and S does not undergo Cannizzaro reaction.✓ Correct
Answer: (C), (D)
Solution
From the reaction schemes provided:
P is terephthalic acid (benzene-1,4-dicarboxylic acid)
Q is phthalic acid (benzene-1,2-dicarboxylic acid)
R is phthalic acid (same as Q)
S is an aldehyde
(A) P (terephthalic acid) is a monomer of dacron (polyethylene terephthalate), but Q (phthalic acid) is a monomer of glyptal. However, the statement needs verification based on the actual products.
(B) P and Q are dicarboxylic acids, but R is also phthalic acid (dicarboxylic acid), and S is an aldehyde, not a dicarboxylic acid.
(C) Q and R are both phthalic acid—correct.
(D) R (phthalic acid) has no α-hydrogen, so it cannot undergo aldol condensation. S (if it's an aldehyde with α-hydrogen) can undergo aldol, but if it lacks α-hydrogen, it undergoes Cannizzaro. The statement says S does not undergo Cannizzaro, which would be true if S has α-hydrogen.
Based on the solution provided, (C) and (D) are correct.
JEE Advanced · 2023 · 04 Jun 2023 · Paper 2 · One or more correct options
