Thermodynamics: Gibs free energy

[ortegavs]

Homework Statement

What is the standard Gibbs free energy of formation of water vapor at 25 C, if , for the reaction shown below under standard conditions, Δ H = -484 KJ/mol and ΔS= -89 J/mol K?
2H2(g) + O2(g) >>> 2H2O(g)

Homework Equations

ΔG = ΔH - TΔS

The Attempt at a Solution

I converted 25 C to kelvin. I then simply plugged in the values. -484000J/mol -(298K(-89J/mol k)) I get -457 kJ/mol. Answer provided is -227. I don't understand how they got this number.

 

[ortegavs]

I think I understand. The answer that I provided is for the equation which has 2 mols of water. The correct answer is kJ/mol not per 2mols so I have to divide by 2 to get the correct answer. Can someone back me up on this?