What is the oxidation number for oxygen in H2O2; for OF2 ? Explain. Solution In H2O2 The oxidation number of Oxygen is -1. The oxidation number of Oxygen in compounds is usually -2, but it is -1 in peroxides. Another Way The oxidation number of H is +1. For two H atoms, the sum is +2. Since H2O2 is a neutral compound (no charge), (The sum of the oxidation numbers of all the atoms in a neutral compound is 0.) The total oxidation number of the two O atoms must be -2. Hence the oxidation number of one oxygen atom must be -1. For OF2 The electronegativity of F is 4.0 and of O 3.5, so Oxygen is surely (+) in this compound. Oxidation number of F2 is -1 Let oxidation number of O be n n+ 2*(-1) = 0 n= 2 oxidation number of Oxyfen is 2..