Dicarboxylic acids have two dissociation constants, one for the initial dissociation into a rnonoanion and onefor the second dissociation into a dianion . For oxalic acid, HO,C-CO,H, the first ionization constant haspKaj = 1.2 and the second ionization constant has pKaz = 4.2. Why is the second carboxyl group so much lessacidic than the first?

Acids are sour substances with pH values less than 7. Acids can donate their protons. There are two…

Dicarboxylic acids have two dissociation constants, one for the initial dissociation into a rnonoanion and one for the second dissociation into a dianion . For oxalic acid, HO2C-CO.H, the first ionization constant has pKaj = 1.2 and the second ionization constant has pKaz = 4.2. Why is the second carboxyl group so much less acidic than the first?

Dicarboxylic acids have two dissociation constants, one for the initial dissociation into a rnonoanion and one for the second dissociation into a dianion . For oxalic acid, HO2C-CO.H, the first ionization constant has pKaj = 1.2 and the second ionization constant has pKaz = 4.2. Why is the second carboxyl group so much less acidic than the first?

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter4: Acids And Bases

Section4.6: Molecular Structure And Acidity

Problem 1Q: Acid-Base Equilibria Many factors contribute to the acidity of organic compounds. Electronegativity,...

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Acid-Base Equilibria Many factors contribute to the acidity of organic compounds. Electronegativity, resonance, induction, hybridization, aromaticity, and atomic size, all play a role. In the following comparisons, you are asked to identify the factor(s) that would be most important to analyze when predicting relative acidity, and then to predict the trend in acidity and pKa values. For each of the following pairs of compounds answer the following two multiple-choice questions. 1. What factor(s) are the most important to consider when predicting the relative acidity of the two compounds? a. Electronegativity of the atom possessing the hydrogen. b. Resonance stabilization of the anionic conjugate base. c. Inductive stabilization of the anionic conjugate base. d. Hybridization of the atom possessing the hydrogen. e. The atomic size of the atom possessing the hydrogen.
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