# Temperature in the Gibbs Free Energy equation

My professor gave us 2 different ways to calculate this problem. I did it using the Clausis-Clapeyron equation.

However, I don't quite get the second method because I thought that if the change in enthalpy and entropy of formation are in standard states, the temperature (T) in the Gibbs Free Energy equation meant to be 298K? And then making the temperature in the second equation 1100K, to find the equilibrium constant?