Which statement about the pKa value is false? The pKa value is calculated from the equilibrium constant for the dissociation of the acid. The pKa value is a measure of the strength of an acid. The pKa value of a given acid gives an indication of the strength of the conjugate base of that acid. A larger pKa value indicates a stronger acid and a weaker associated conjugate base. All of these statements are correct.

Which statement about the pKa value is false? The pKa value is calculated from the equilibrium constant for the dissociation of the acid. The pKa value is a measure of the strength of an acid. The pKa value of a given acid gives an indication of the strength of the conjugate base of that acid. A larger pKa value indicates a stronger acid and a weaker associated conjugate base. All of these statements are correct.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter15: Complex Acid/base Systems

Section: Chapter Questions

Problem 15.34QAP

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In my slide, there is a table summarizing the pKa values for different acids. (1) when ranking the acidity level (how strong the acids are), a low pKa means high acidity. Why is that? (2) Calculate the phosphoric acid solution pH when the ratio of [H2PO4-]/[H3PO4] is 0.8.
3-(N-Morpholino)-2-hydroxy-propanesulfonic acid (MOPSO) is a common buffer used in biology and biochemistry to maintain solutions near physiological pH. The structure of MOPSO is given below. MOPSO has a pKa value of 6.90. Consider the following solutions made by dissolving MOPSO in water. b. Determine the pH when 0.015 mole of MOPSO is dissolved in 500 mL of distilledwater.c. Determine how many milliliters of 0.1 M LiOH must be added to the solution described in part b to make a buffer of pH 7.0.
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The pKa values of 4 acids are given below. Acid HA1 HA2 HA3 HA4 pKa 4.76 3.45 7.63 5.23 Which of the following solutions does have the highest pH? Choose one option only. Options: a. 0.30 M A2- (aq) (conjugate base of HA2) b. 0.30 M A3- (aq) (conjugate base of HA3) c. 0.30 M A1- (aq) (conjugate base of HA1) d. 0.30 M A4- (aq) (conjugate base of HA4) e. All the 0.30 M bases in this question have the same solution pH.
Given a solution of 0.0025 M HC2H3O2, Ka = 1.8 x 10^-5 a. Calculate the pH of the solution. b. Calculate pKa. c. Calculate the Kb value for C2H3O2-.
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pH = 7.15 + log [0.25]/[0.50] pH = pKa + log [0.33]/[0.11]; (Ka = 6.3096 x 10-8) [OH-] = 2.78 x 10-4 % ionization of 34 relative to pKa value
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