Chapter 14.4, Problem 14.30QAP

Consider the following acids and their dissociation constants:

${\text{HPO}}_{\text{4}}{}^{\text{2}-}\left(aq\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right) \rightleftharpoons {\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\left(aq\right)+{\text{PO}}_{\text{4}}{}^{\text{3-}}\left(aq\right){\text{ K}}_{\text{a}}=\text{ 2}.\text{2 }\times \text{ 1}{0}^{\text{-13}}$

${\text{HCHO}}_{\text{2}}\left(aq\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right) \rightleftharpoons {\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\left(aq\right)+{\text{CHO}}_{\text{2}}{}^{-}\left(aq\right){\text{ K}}_{\text{a}}=\text{ 1}.\text{8 }\times {\text{ 10}}^{\text{-4}}$

a. Which is the weaker acid, ${\text{HPO}}_{\text{4}}{}^{\text{2}-}$ or ${\text{HCHO}}_{\text{2}}$ ?

b. What is the conjugate base of ${\text{HPO}}_{\text{4}}{}^{\text{2}-}$ ?

c. Which acid has the weaker conjugate base?

d. Which acid has the stronger conjugate base?

e. Which acid produces more ions?