Answer to Question #142468 in General Chemistry for yara

Question

is this element is reduced or is oxidized. Justify your answers

H2 + O2 → H2O

Answer 1

The oxidation number of H is +1. The oxidation number of a free element is always 0. The oxidation number of O in compounds is usually -2.

An atom is oxidized if its oxidation number increases, the reducing agent, and an atom is reduced if its oxidation number decreases, the oxidizing agent. So in this reaction Hydrogen is oxidized, Oxygen is reduced.