Ask a Question

What is the correct order of pKa values of the following acids?

← Prev Question Next Question →
+1 vote
260 views
in Chemistry – Class 12 by (188k points)
What is the correct order of pKa values of the following acids?

(a) Benzoic acid > m-Nitrobenzoic acid > p-Nitrobenzoic acid

(b) Benzoic acid > p-Nitrobenzoic acid > m-Nitrobenzoic acid

(c) p-Nitrobenzoic acid > m-Nitrobenzoic acid > Benzoic acid

(d) m-Nitrobenzoic acid > p-Nitrobenzoic acid > Benzoic acid

This question was addressed to me during a job interview.

My question is based upon Carboxylic Acids Chemical Reactions in portion Aldehydes, Ketones and Carboxylic Acids of Chemistry – Class 12

1 Answer

+1 vote
by (2.1m points)
selected by
 
Best answer
Right choice is (a) Benzoic acid > m-Nitrobenzoic acid > p-Nitrobenzoic acid

Easy explanation: Nitro group is electron withdrawing in nature and increases the acidic strength of acids. The electron withdrawing effect of NO2 is pronounced at para position more than meta position, hence the p-isomer is more acidic and has a lower pKa value than m-isomer.

Related questions

Welcome to TalkJarvis QnA, a question-answer community website for the people by the people. On TalkJarvis QnA you can ask your doubts, curiosity, questions and whatever going in your mind either related to studies or others. Experts and people from different fields will answer.

Most popular tags

biology – class 12 biology – class 11 construction & building materials chemistry – class 12 electronic devices & circuits network theory data structures & algorithms ii cell biology ic engine insurance finance money computational fluid dynamics engineering physics i discrete mathematics chemistry – class 11 aerodynamics casting-forming-welding i engineering mathematics operating system casting-forming-welding ii engineering drawing mysql engineering geology digital circuits wireless mobile energy management electrical measurements digital communications cyber security analytical instrumentation embedded systems electric drives cytogenetics advanced machining computer fundamentals life sciences basic civil engineering iot design of electrical machines physics – class 12 applied chemistry dairy engineering basic chemical engineering cloud computing microprocessor bioinformatics aircraft design aircraft maintenance software engineering drug biotechnology digital signal processing biochemistry data structures & algorithms i automotive engine design avionics engineering material & metallurgy energy engineering cognitive radio unix electrical machines biomedical instrumentation object oriented programming electromagnetic theory power electronics analog communications bioprocess engineering civil engineering drawing engineering metrology physics – class 11 mathematics – class 12 engineering chemistry i basic electrical engineering unit processes mongodb signals and systems cryptograph & network security hadoop mathematics – class 11 engineering physics ii html control systems engineering mechanics antennas analog circuits computer network java sql server javascript concrete technology chemical process calculation artificial intelligence design of steel structures c++ database management computer architecture engineering chemistry ii corrosion engineering chemical technology dc machines
Powered by TalkJarvis
...