Answer: In the reaction 2H2S + 3O2 → 2H2O + 2SO2, the oxidation state of sulfur changes from -2 in H2S to +4 in SO2. This means that sulfur is oxidized, and oxygen is reduced.
Step-by-step explanation:
The oxidation state of an element is the number of electrons that an atom loses or gains when it forms a chemical bond. In H2S, the sulfur atom has an oxidation state of -2 because it has lost two electrons to the hydrogen atoms. In SO2, the sulfur atom has an oxidation state of +4 because it has gained four electrons from the oxygen atoms.
The oxidation state of oxygen changes from 0 in O2 to -2 in H2O and SO2. This means that oxygen is reduced, and sulfur is oxidized. In O2, the oxygen atoms are not bonded to any other atoms, so they have an oxidation state of 0. In H2O and SO2, the oxygen atoms have an oxidation state of -2 because they have gained two electrons from the hydrogen and sulfur atoms, respectively.
Element Oxidation state in H2S Oxidation state in SO2 Oxidation state in H2O
Sulfur -2 +4 +4
Oxygen 0 -2 -2
Hydrogen +1 +1 +1