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**[SOLVED] free energy of formation**

**1. Homework Statement**

Consider the reaction

2NH3(g) --> N2(g) + 3H2(g)

If the standard molar free energy of formation of NH3(g) at 298 K is –16.45 kJ·mol–1, calculate the equilibrium constant for this reaction at 298 K.

The correct answer is 1.71E-6

**2. Homework Equations**

DG= - RTlnK

**3. The Attempt at a Solution**

so, if the equation is for two moles NH3(g) then one would multiply the given DG (-16.45) by 2. Also, I converted from KJ to J giving me -32900. The equation given is for the reverse process of formation, so, do I reverse the sign of DG? I tried it both ways and got the wrong answer. In fact, I get huge numbers compared to the correct answer.

I used 8.3145 for R and 298 for T.