HIn H + I¯ color 1 color 2 The following absorbance data were obtained for a 5.00 × 104 M solution of HIn in 0.1 M NaOH and 0.1 M HCl. Measurements were made at a wavelength of 485 nm and 625 nm with 1.00-cm cells. 0.1 M NaOH: 0.1 M HCl: A485 0.05 A485=0.6 A625 = 0.8 A625 = 0.2 In the NaOH solution, essentially all of the indicator is present as In; in the acidic solution, it is essentially all in the form of HIn. Please calculate the acid dissociation constant for the indicator if a pH 5.00 buffer containing a small amount of the indicator exhibits an absorbance of 0.5 at 485 nm and 0.4 at 625 nm (1.00-cm cells).

HIn H + I¯ color 1 color 2 The following absorbance data were obtained for a 5.00 × 104 M solution of HIn in 0.1 M NaOH and 0.1 M HCl. Measurements were made at a wavelength of 485 nm and 625 nm with 1.00-cm cells. 0.1 M NaOH: 0.1 M HCl: A485 0.05 A485=0.6 A625 = 0.8 A625 = 0.2 In the NaOH solution, essentially all of the indicator is present as In; in the acidic solution, it is essentially all in the form of HIn. Please calculate the acid dissociation constant for the indicator if a pH 5.00 buffer containing a small amount of the indicator exhibits an absorbance of 0.5 at 485 nm and 0.4 at 625 nm (1.00-cm cells).

Chemistry & Chemical Reactivity

9th Edition

ISBN:9781133949640

Author:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Publisher:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Chapter4: Stoichiometry: Quantitative Information About Chemical Reactions

Section4.8: Stoichiometry Of Reactions In Aqueous Solution-titrations

Problem 2RC

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