I don't understand. The strong acid should prevent the dissociation of HX.
I understood aboue e).
The question was: Is absorbance linearly related to the wavelength?
If strong acid, equilibrium shifts pretty much completely to the left, correct? Meaning that the concentration of [HX] in solution is always the concentration of [HX] you begin with. So the concentrationof HX in solution after equilibrium, [HX]e
, is the concentration you put into solution to begin with [HX]0
. So if [HX]0
= n, then [HX]e
= n in a strongly acidified solution.
Absorbance, A is given by A = ε [HX]e
L, and ε and L don't change as a function of n. Therefore A = ε n L and since ε and L are constant, A is linear with respect to n, or [HX]0
(I guess use of n was superfluous. But easier to write out.
Now do the same thing for the more complicated problem where both [HX] and [X] are absorbing using the same method.
Re: your other question. I don't understand it. The plot is absorption vs concentration, not vs. wavelength. Absorption changes as a function of wavelength because the extinction coefficient changes as a function of wavelength, and the dependence is far from linear. There are peaks associated with molecular absorption.
Fixed a small typo. Also, just keep in mind that in general, A(λ) = εHX,λ
L + εX-,λ
L, where in the case I've described εX-,λ
= 0 measured at λ.