Chapter 21, Problem 51QAP

Consider the equilibrium system
$\text{HF}\left(aq\right)\rightleftharpoons {\text{H}}^{+}\left(aq\right)+{\text{F}}^{-}\left(aq\right)$
Given $\Delta H_{\text{f}}\text{°HF}\left(aq\right)=-320.1\text{kJ}/\text{mol}$ , $\Delta H_{\text{f}}{\text{°F}}^{-}\left(aq\right)=-332.6\text{kJ}/\text{mol}$ ; $S^{°}{\text{F}}^{-}\left(aq\right)=-13.8\text{kJ}/\text{mol}\cdot \text{K}$ ; $K_{\text{a}}\text{HF}=6.9\times {10}^{-4}$ at 25°C
calculate S° for HF(aq).