4. The molar absorptivities of the indicator weak acid HIn (K₁ = 1.42 x 105) and its conjugate base In at 570 were determined as &(HIn) = 7120 and ɛ(In)=961. The optical length b = 1.00 cm. (a) What is the absorbance of an unbuffered indicator solution having total indicator concentration 8.0 × 10%. (b) What is the absorbance of a buffered indicator solution having total indicator concentration 8.0 x 105 and pH = 6.5.

4. The molar absorptivities of the indicator weak acid HIn (K₁ = 1.42 x 105) and its conjugate base In at 570 were determined as &(HIn) = 7120 and ɛ(In)=961. The optical length b = 1.00 cm. (a) What is the absorbance of an unbuffered indicator solution having total indicator concentration 8.0 × 10%. (b) What is the absorbance of a buffered indicator solution having total indicator concentration 8.0 x 105 and pH = 6.5.

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter13: An Introduction To Ultraviolet-visible Molecular Absorption Spectrometry

Section: Chapter Questions

Problem 13.11QAP: The equilibrium constant for the conjugate acid-base pair HIn+H2OH3O++In is 8.00 10-5. From the...

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