1.

The incorrect expression among the following isA. `(DeltaG_("system"))/(DeltaG_("total"))=-T`B. in isothermal process, `W_("reversible")=-nRT"in"(V_(f))/(V_(i))`C. In `K=(DeltaH-TDeltaS^(@))/(RT)`D. `K=e^(-DeltaG^(@)//RT)`

Answer» Correct Answer - C
According to Gibbs Helmholtz equation,
`DeltaG=DeltaH-TDeltaS`
(a) For a system, total entropy change `=DeltaS_("total")`
`Delta_("total")=0`
`:. DeltaG_("system")=-TDeltaS_("total")`
`:. (DeltaG_("system"))/(DeltaS_("total"))=-T`
Thus, `(a)` is correct.
(b) For isothermal reversible process, `DeltaE=0`
By first law of thermodynamics, `DeltaE=q+W`
`:. W_("reversible")=-q=-int_(v_(i))^(v_(f))pdV`
`implies W_("reversible")=-RT` In `(V_(f))/(V_(i))`
Thus, `(b)` is correct
(c) `DeltaG^(@)+DeltaH^(@)-TDeltaS^(@)`
Also, `DeltaG^(@)=-RT` In `K`
In `K=((DeltaH^(@)-TDeltaS^(@)))/(RT)`
In `K=(DeltaG^(@))/(RT)` [from Eq. (i)]
(d) The standard free energy `(DeltaG^(@))` is related to equilibrium constant `K` as
`DeltaG^(@)=-RT` In `K`
`:.` In `K=-(DeltaG^(@))/(RT)`
`k=-e^(-DeltaG^(@)//Rt)`
Thus, `(d)` also correct.


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