Substance X Has a Heat of Vaporization of 55 $\rightarrow$ X(g) at 1 Atm and 423°C, Calculate the Value Of

Substance X has a heat of vaporization of 55.4 kJ/mol at its normal boiling point (423°C) . For the process X(l) $\rightarrow$ X(g) at 1 atm and 423°C, calculate the value of:
- $\Delta$ G

A) 79.6 J/K•mol
B) -79.6 J/K•mol
C) 0
D) 103 J/K•mol
E) -103 J/K•mol