0.10 moles of an acidic substance A is dissolved in water to form a 1.0L solution. Kw = 1.00x1014. (a) If A is HCN, calculate the pH of he solution and check whether we can use the assumption, [H'] << total concentration of A, during the calculation. Ka(HCN) = 6.2x1010 (b) If A is NaHSO4, calculate the pH of the solution and check whether we can use the assumption, [H*] « total concentration of A, during the calculation. Ka(HSO4) = 1.2x102 (c) Again, the relative error we can accept for the calculated [H*] is within 5% of the true value by using the assumption (i.e., [H*] << total concentration of [A]) for the calculation. What is the maximum Ka for A that makes the assumption acceptable?

0.10 moles of an acidic substance A is dissolved in water to form a 1.0L solution. Kw = 1.00x1014. (a) If A is HCN, calculate the pH of he solution and check whether we can use the assumption, [H'] << total concentration of A, during the calculation. Ka(HCN) = 6.2x1010 (b) If A is NaHSO4, calculate the pH of the solution and check whether we can use the assumption, [H] « total concentration of A, during the calculation. Ka(HSO4) = 1.2x102 (c) Again, the relative error we can accept for the calculated [H] is within 5% of the true value by using the assumption (i.e., [H*] << total concentration of [A]) for the calculation. What is the maximum Ka for A that makes the assumption acceptable?

Chemistry: Principles and Reactions

8th Edition

ISBN:9781305079373

Author:William L. Masterton, Cecile N. Hurley

Publisher:William L. Masterton, Cecile N. Hurley

Chapter14: Equilibria In Acid-base Solutions

Section: Chapter Questions

Problem 60QAP: Consider an aqueous solution of HF. The molar heat of formation for aqueous HF is -320.1 kJ/mol. (a)...

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