Question

Compound Use the data given in the table to calculate the value of AGixn at 25° C for the reaction described by the equation AG; (kJ/mol) +387.7 -614.9 +402.0 A+B = C AGixn = kJ mol If AHixn and ASixn are both positive values, what drives the spontaneous reaction and in what direction at standard conditions? The spontaneous reaction is enthalpy-driven to the right. The spontaneous reaction is entropy-driven to the left. The spontaneous reaction is entropy-driven to the right. The spontaneous reaction is enthalnv-driven to the left

Answer 1

1)

Given:

Gof(A) = 387.7 KJ/mol

Gof(B) = -614.9 KJ/mol

Gof(C) = 402.0 KJ/mol

Balanced chemical equation is:

A + B ---> C

ΔGo rxn = 1*Gof(C) - 1*Gof( A) - 1*Gof(B)

ΔGo rxn = 1*(402.0) - 1*(387.7) - 1*(-614.9)

ΔGo rxn = 629.2 KJ

Answer: 629.2 KJ

2)

Since ΔGo rxn is positive, the reaction is spontaneous to the left.

ΔGo rxn = ΔHo rxn - T*ΔSo rxn

ΔGo rxn is positive because negative value of ΔSo rxn

So, this is entropy driven

Answer: option 2