Chapter 14, Problem 32Ci

In the kidneys, the ammonia buffer system buffers high ${\text{H}}_3{\text{O}}^{+}$ . Ammonia, which is produced in renal tubules from amino acids, combines with ${\text{H}}^{+}$ to be excreted as ${\text{NH}}_4\text{Cl}$ . At body temperature $\left({37}^{°}\text{C}\right)$ , the $K_{\text{a}}=5.6\times {10}^{-10}$ . A buffer solution with a volume of $125\text{mL}$ contains $3.34\text{g}$ of ${\text{NH}}_4\text{Cl}$ and $0.0151\text{g}$ of ${\text{NH}}_3\cdot (7.2,7.3,8.4,14.9)$
${\text{NH}}_4^{+}(aq)+{\text{H}}_2\text{O}(l)\rightleftarrows {\text{NH}}_3(aq)+{\text{H}}_3{\text{O}}^{+}(aq)$
a. What is the $\left[{\text{NH}}_4^{+}\right]$ ?
b. What is the $\left[{\text{NH}}_3\right]$ ?
c. What is the $\left[{\text{H}}_3{\text{O}}^{+}\right]$ ?
d. What is the $\text{pH}$ of the buffer?
e. Write a balanced chemical equation that shows how this buffer neutralizes added acid.
f. Write a balanced chemical equation that shows how this buffer neutralizes added base.