1. Derive the theoretical binding curve for a monoprotic acid (binding fraction as a function of hydrogen ion concentration), starting with the equilibrium expression for a weak acid. 2. Consider two weak acids, with pKa values of 1.8 and 4.5. Calculate the fraction binding of each for the case when pH = pKa, and the fraction binding when pH = 6.0. 3. When we say the pH = pKa at the midpoint of a titration curve, we are assuming slight dissociation of weak acids. What does your answer to question 2 say about the validity of this assumption? 4. In class we discussed how to convert titration data to binding curve data. For a titration with the following calculate the fraction bound. [OH-] = 0.100 Endpoint volume: 15.0 ml Initial volume of acid: 25.0 ml Base added: 7.50 ml pH = 1.6, 4.45 5. For the answers in 4, use the calculated fraction bound and the pH to calculate the Kd values in each case. Submit this on the form on the home page.

1. Derive the theoretical binding curve for a monoprotic acid (binding fraction as a function of hydrogen ion concentration), starting with the equilibrium expression for a weak acid. 2. Consider two weak acids, with pKa values of 1.8 and 4.5. Calculate the fraction binding of each for the case when pH = pKa, and the fraction binding when pH = 6.0. 3. When we say the pH = pKa at the midpoint of a titration curve, we are assuming slight dissociation of weak acids. What does your answer to question 2 say about the validity of this assumption? 4. In class we discussed how to convert titration data to binding curve data. For a titration with the following calculate the fraction bound. [OH-] = 0.100 Endpoint volume: 15.0 ml Initial volume of acid: 25.0 ml Base added: 7.50 ml pH = 1.6, 4.45 5. For the answers in 4, use the calculated fraction bound and the pH to calculate the Kd values in each case. Submit this on the form on the home page.

Principles of Modern Chemistry

8th Edition

ISBN:9781305079113

Author:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Publisher:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Chapter20: Molecular Spectroscopy And Photochemistry

Section: Chapter Questions

Problem 67CP

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