[Mikez]

I am having trouble with the derivation for the chemical potential of liquid component of a system.

We have a closed system with 2 components in their liquid and gas form

This is the line that doesn't make sense to me:
uo(g)=u1o(g)
Isn't this saying that total chem pot of the gas phase (of both components) is equal to the chem pot of 1 component???

the final equation is
u1(l)=u1*(l)+ RT ln[p1/P*]


u1 = chem pot of component 1
o = a standard condition
*= pure
u= chem pot

thanks so much