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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: DannyBoy on April 24, 2014, 10:48:50 AM

Title: Free Energy
Post by: DannyBoy on April 24, 2014, 10:48:50 AM

I've seen the Gibbs free energy of a reaction given in J/mol, but per moles of what? For example, 0.5 O₂ + H₂ :rarrow: H₂O. Is ΔG for this reaction per moles of product (i.e., water) or reactant? If so, which reactant? Or is per mole of reaction – whatever that may mean?! ??? Help would be greatly appreciated!

Title: Re: Free Energy
Post by: Borek on April 24, 2014, 11:15:11 AM

Most likely per the mole of reaction. In this particular case - per half mole of oxygen consumed, per mole of hydrogen consumed, per mole of water consumed.

Generally speaking it is up to whoever posted/gave the information to make it unambiguous. If it is not clear what they mean, ask. If there is no one to ask - ignore.

Title: Re: Free Energy
Post by: DannyBoy on April 24, 2014, 11:21:35 AM

Makes sense. Thanks!