Chapter 9, Problem 9.112E

Write equations similar to Equations 9.48 and 9.49 of the text to illustrate how a mixture of sodium hydrogen phosphate $\left({\text{NaH}}_{\text{2}}{\text{PO}}_{\text{4}}\right)$ and sodium dihydrogen phosphate $\left({\text{Na}}_2{\text{HPO}}_{\text{4}}\right)$ could function as a buffer when dissolved in water. Remember that phosphoric acid $\left({\text{H}}_3{\text{PO}}_{\text{4}}\right)$ ionizes in three steps.