Question #7b856

1 Answer
Jan 26, 2015

Since this is an equilibrium reaction, the data given point to the formation of more reactants.

The Gibbs free energy change for a system that has a reaction quotient equal to Q_c is

DeltaG_("rxn") = DeltaG^@ + RT * ln(Q_c)

You know that at equilibrium, DeltaG = 0 and DeltaG^@ = -RT * ln(K_c)where K_c is the equilibrium constant for the reaction.

The above equation can be written as

DeltaG_("rxn")= - RT * ln(K_c) + RT * ln(Q_c), or

DeltaG_("rxn") = RT * ln(Q_c/K_c)

This means that

ln(Q_c/K_c) = (DeltaG_("rxn"))/(RT)

Since R and T will always be positive, the value on the right of the equation is positive, which means that (Q_c)/(K_c) is greater than 1, or that Q_c is greater than K_c .

This means that the reverse reaction will be spontaneous and the formation of more reactants will be favored.