Question
II. Calculation An indicator has a molar absorption of 2.080 M'1 cm1 for HIn and 14200 M1 cm1 for In', at wavelength of 440 nm. HInHIn (a) (2 pts) Write a Beer's law expression for the absorbance at 440 nm of a solution in a 1.00-cm cuvet containing the concentration (HIn] and [In]. (b) (8 pts) A solution of HIn adjusted to pH 6.23 contains a mixture of HIn and In with a total concentration of 1.84 x 10 M. The absorbance at 440 nm is 0.868. From your expression from (a) and the mass balance [HIn]+ [In] = 1.84 x 10-4 M. Calculate pKHin-
Explanation / Answer
II. Calculation An indicator has a molar absorption of 2.080 M'1 cm1 for HIn an