Q4. The acid base indicator HIn undergoes the following reaction in dilute aqueous solution 10 H+ + In HIn When a 5x10-4 M solution of HIn put in 0.1 M NaOH and in 0.1 M HCl, the following data were obtained. Note that all the indicator will be existing as HIn in 0.1 M HCl and existing as In in NaOH, Solution 0.1 M NaOH 0.1 M HCI A at 485 nm 0.052 0.454 A at 625 nm 0.823 0.176 Calculate a) The molar absorptivity of HIn and In" at 485 and 625 nm b) The acid dissociation constant (Ka) if a small amount of the indicator at pH 5 gave A = 0.472 at 485 nm and A = 0.351 at 625 nm.

Q4. The acid base indicator HIn undergoes the following reaction in dilute aqueous solution 10 H+ + In HIn When a 5x10-4 M solution of HIn put in 0.1 M NaOH and in 0.1 M HCl, the following data were obtained. Note that all the indicator will be existing as HIn in 0.1 M HCl and existing as In in NaOH, Solution 0.1 M NaOH 0.1 M HCI A at 485 nm 0.052 0.454 A at 625 nm 0.823 0.176 Calculate a) The molar absorptivity of HIn and In" at 485 and 625 nm b) The acid dissociation constant (Ka) if a small amount of the indicator at pH 5 gave A = 0.472 at 485 nm and A = 0.351 at 625 nm.

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter15: Acid-base Equilibria

Section: Chapter Questions

Problem 132IP: A 10.00-g sample of the ionic compound NaA, where A is the anion of a weak acid, was dissolved in...

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