[dfx-]

I have plenty of explanations of it 'in English' of what the Gibbs/Helmholtz equation actually gives, but none of it is still clear to me...




Secondly in Brunaer's classification - with regard to chemisorption and physisorption, I keep forgetting how to go about getting V_m..

I know the questions above are quite broad, but I'll see upon further study between now and tomorrow if I get can shorten it any further if the above information doesn't help.

[Donaldson Tan]

I have plenty of explanations of it 'in English' of what the Gibbs/Helmholtz equation actually gives, but none of it is still clear to me...

G = H - TS => dG = dH - d(TS)
A = U - TS => dA = dU -d(TS)

We denote energy change for an open system using: dH = Q + W
We denote energy change for a close system using  : dU = Q + W
Hence, dH for an open system is equivalent to dU for a close system

Hence, you can regard the Helmholtz Equation as the equivalent of the Gibb equation for a close system. The Gibb equation applies for an open system. G describes the free energy available in an open system, whereas the Helmholtz equation describes free energy available in a close system.