## General, Organic, and Biological Chemistry: Structures of Life (5th Edition)

a. $HP{O_4}^{2-}$ b. $P{O_4}^{3-}$ c. $HCHO_2$ d. $HP{O_4}^{2-}$ e. $HCHO_2$
a. Since $HP{O_4}^{2-}$ has a smaller $K_a$ value than $HCHO_2$, it is a weaker acid. $$2.2 \times 10^{-13} \lt 1.8 \times 10^{-4}$$ b. As we can see by the reaction, when $HP{O_4}^{2-}$ loses a proton, it produces $P{O_4}^{3-}$. c. The stronger the acid, the weaker its conjugate base. Therefore, $HCHO_2$ has the weaker conjugate base. d. The weaker the acid, the stronger its conjugate base. Thus, $HP{O_4}^{2-}$ has the stronger conjugate base. e. The stronger acid produces more ions. So, $HCHO_2$ produces more ions.