Concept explainers
Interpretation:
The pKa of five substituted benzoic acids are given. Based on the pKa values, the corresponding substituted benzenes are to be arranged in the increasing order of their reactivity towards
Concept introduction:
Electron releasing substituents present on the benzene ring in substituted benzoic acids destabilize the carboxylate anion and make the acids less acidic. Electron withdrawing substituents present on the benzene ring in substituted benzoic acids stabilize the anion and make the acids more acidic. Lower the pKa value the stronger the acid.
The effects are reversed in aromatic electrophilic substitution reactions. Electron releasing substituents activate the ring towards electrophiles while the electron withdrawing substituents deactivate the ring towards electrophiles.
Thus groups which are good activators reduce the acidity of the acid.
To arrange:
The substituted benzenes in the five
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Chapter 20 Solutions
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- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning