Chapter 12, Problem 27E

By calculating △S_univ, at each temperature, determine if the melting of 1 mole of NaCl(s) is spontaneous at 500 °C and at 700 °C..

$S{°}_{\text{NaCl}\left(s\right)}=72.11\frac{\text{J}}{\text{mol}\cdot \text{K}}$ $S{°}_{\text{NaCl}\left(l\right)}=95.06\frac{\text{J}}{\text{mol}\cdot \text{K}}$

$\Delta H{°}_{\text{Fusion}}=27.95\text{kJ}/\text{mol}$

What assumptions are made about the thermodynamic information (entropy and enthalpy values) used to solve this problem?