An acid-base indicator, HIn, dissociates according to the reaction shown in an aqueous solution. K Hin HIn(aq) In (aq) + H* (aq) The protonated form of the indicator, HIn, has a molar absorptivity of 2039 M-' -cm-' and the deprotonated form, In¯, has a molar absorptivity of 13970 M-' -cm-' at 440 nm. The pH of a solution containing a mixture of HIn and In¯ is adjusted to 6.04. The total concentration of HIn and In¯ is 0.000123 M. The absorbance of this solution was measured at 440 nm in a 1.00 cm cuvet and was determined to be 0.781. Calculate pK, for HIn. pKa, Hin =

An acid-base indicator, HIn, dissociates according to the reaction shown in an aqueous solution. K Hin HIn(aq) In (aq) + H* (aq) The protonated form of the indicator, HIn, has a molar absorptivity of 2039 M-' -cm-' and the deprotonated form, In¯, has a molar absorptivity of 13970 M-' -cm-' at 440 nm. The pH of a solution containing a mixture of HIn and In¯ is adjusted to 6.04. The total concentration of HIn and In¯ is 0.000123 M. The absorbance of this solution was measured at 440 nm in a 1.00 cm cuvet and was determined to be 0.781. Calculate pK, for HIn. pKa, Hin =

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter16: Applications Of Neutralization Titrations

Section: Chapter Questions

Problem 16.20QAP

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