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## 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, ΔH = -484 kJ/mol and ΔS=-89 J/mol K?

2H

_{2}+ O

_{s}→2H

_{2}O

## Homework Equations

ΔG = ΔH-TΔS

## The Attempt at a Solution

Usually I can do these problems with no issue but I cannot seem to get the correct answer (which is -229 kJ/mol).

First, I converted -89 J/mol K to kJ = 0.089 J/mol K. Plugging this into the equation gives me:

ΔG = (-484 kJ/mol) - 298 K(-.089 kJ/mol K) = -457 kJ/mol.

I did this problem twice, making sure my units were correct. Is my book wrong or did I do something wrong in the calculations? Thanks in advance.