Practice Test 8

For the reaction $\text{Fe}^{3+}(aq)+\text{SCN}^-(aq)\rightleftharpoons \text{FeSCN}^{2+}(aq)$ at a given temperature, the equilibrium constant is very large. What does this indicate about the equilibrium mixture?

A buffer contains $0.10\ \text{M}$ $\text{H}_2\text{PO}_4^-$ and $0.20\ \text{M}$ $\text{HPO}_4^{2-}$. Given $\text{p}K_a(\text{H}_2\text{PO}_4^-)=7.21$, what is the pH of the buffer?