For each mol of substrate oxidized Complexes I, III, and IV in the respiratory chain NADH, --- mol of ATP are formed?

For each mol of substrate oxidized Complexes I, III, and IV in the respiratory chain (ie, NADH), 2.5 mol of ATP are formed per 0.5 mol of O2 consumed; ie, the P:O ratio = 2.5. On the other hand, when 1 mol of the substrate (eg, succinate or 3-phosphoglycerate) is oxidized Complexes II, III, and IV, only 1.5 mol of ATP are formed; that is, P:O = 1.5. These reactions are known as oxidative phosphorylation at the respiratory chain level. Reference: Harper; 30th edition; Page no: 131