General Chemistry: Principles and Modern Applications (10th Edition)

(1) To convert 3 mol $O_2$ into 2 mol $O_3$, the Gibbs energy change for the system is 326.4 KJ. (2) If 1.75 mol $O_2$ reacts, the Gibbs free energy change for the new system is (326.4 KJ / 3 mol $O_2$) $\times$ (1.75 mol $O_2$).