[galpinj]

Hey guys,

I've been looking at the hydrolysis of ATP, and I have a question regarding ΔG = ΔH - TΔS. From what I understand, ΔH encapsulates the change from breaking and forming different bonds in a reaction (leading to either an input or expulsion of heat), while ΔS is a measure of "randomness". Regarding the hydrolysis of ATP, the products are more stable partly because of increased resonance and a separation of charge. How do these variables fit into the Gibbs free energy equation? Is there any way to quantitatively measure variables like these?

Thank you!

[OTI]

You can get ΔH_rxn with Hess's Law. You can also get ΔS_rxn with something similar too.

However, you need to know the number of moles of each product and reactant as well as the ΔH and ΔS of each product and reactant. Then you can calculate ΔG with the ΔH_rxn and the ΔS_rxn. T should be 298K (I think).

That's how you measure it quantitatively.

Dunno about the rest. Hope it helps.

[galpinj]

Yes, a little bit. I think that the standard enthalpy and entropy values must factor in these kinds of potential energies; however, I'd still like to know specifically how that's determined/if my train of thought is correct.

Thank you