Homework 2
MSE244 F2024
due October 1 at 10 am (before class)
Question 1. Four pKa values (1.0, 2.0, 7.0, 9.0) are tabulated for the acid H4 P2 O7 . Write
equations to show the dissociation steps in aqueous solution and assign, with reasoning
(explain in two lines or less), a pKa value to each step.
Question 2. Write equations to illustrate the amphoteric behaviour of [HCO3] in aqueous
solution.
Question 3. The values of pKa (1) and pKa (2) for chromic acid (H2 CrO4 ) are 0.74 and
6.49 respectively. (a) Determine values of Ka for each dissociation step. (b) Write equations
to represent the dissociation steps of chromic acid in aqueous solution
Question 4. (a) To what equilibria do the values of pKa (1) = 10.71 and pKa (2) = 7.56
for the conjugate acid of H2 NCH2 CH2 NH2 refer? (b) Calculate the corresponding values of
pKb and write equations to show the equilibria to which these values refer.
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