+1 vote
in Chemistry by (40.3k points)

Consider the following four compounds I, II, III, and IV.

Choose the correct statement(s). 

(A) The order of basicity is II > I > III > IV. 

(B) The magnitude of pKb difference between I and II is more than that between III and IV. 

(C) Resonance effect is more in III than in IV. 

(D) Steric effect makes compound IV more basic than III.

Please log in or register to answer this question.

1 Answer

+1 vote
by (40.2k points)

Answer: C, D

pKb different between I and II is 0.53 and that of III and IV is 4.6. 

So option (B) is incorrect 

Correct Statement (C), (D) 

The most basic compound in the given option is (II) and least basic compound is (III)

In 2,4,6-trinitro aniline (III) due to strong –R effect of –NO2 groups, the \(\ell\).p. of –NH2 is more involved with benzene ring hence it has least basic strength. 

Whereas (IV) N,N-Dimethyl 2,4,6-trinitro aniline, due to steric inhibition to resonance (SIR) effect; the lone pair of nitrogen is not in the plane of benzene, hence make it (\(\ell\).p.) more free to protonate

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.