(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

For the reaction N2(g) + 3H2(g) <---> 2NH3(g)

I am supposed to determine the equilibrium constant at 298K and 1 bar. We have been given a table that states that

for NH3(g):

[itex]\Delta_{r}G^{\Theta}= -16.45 kJ/mol[/itex]

I know that

[itex]\Delta_{r}G^{\Theta}= \Sigma v G^{\Theta}_{product} - \Sigma v G^{\Theta}_{reactant}[/itex]

where v is the stoichiometric coefficient.

But what is confusing me is that you could also write the equation as

1/2 N2(g) + (3/2)(g) <----> NH3(g)

so in the first case, the answer would be

(2*-16.45 kJ/mol) - ((1*0)+(3*0)) = -32.90 kJ/mol

But in the second case, the answer would be

(-16.45 kJ/mol) - (1/2*0 + 3/2 *0) = -16.45 kJ/mol

Since both equations should be valid, what answer is correct? I don't understand which one I should choose because they both look like the should be right.

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Standard Gibbs of a reaction

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