Di-iodine gas can dissociate into two atoms of iodine gas. At 1200

kelvins, the forward reaction has an equilibrium constant of approximately 10. In kiljoules [KILL-oh-jools] per mole, which of the following is closest to the standard change in Gibbs free energy of this reaction?

W) -20

X) -2

Y) +2

Z) +20
W) -20