Determine the oxidation number of sulfur in each of the following substances: (d) hydrogen sulfide, H2S

Key Concepts

Oxidation Number

The oxidation number, or oxidation state, is a theoretical charge assigned to an atom in a compound based on the assumption that electrons are completely transferred. It helps in understanding the electron distribution in molecules and is crucial for identifying redox reactions. Oxidation numbers can be positive, negative, or zero, depending on the atom's electron gain or loss.

Rules for Assigning Oxidation Numbers

There are specific rules for assigning oxidation numbers, such as the fact that the oxidation number of an element in its standard state is zero, and for monoatomic ions, it equals the charge of the ion. In compounds, hydrogen typically has an oxidation number of +1, while oxygen usually has -2. These rules guide the determination of oxidation states in various compounds.

Hydrogen Sulfide (H2S)

Hydrogen sulfide (H2S) is a simple binary compound consisting of hydrogen and sulfur. In H2S, each hydrogen atom has an oxidation number of +1, leading to a total of +2 from the two hydrogens. To balance this, the sulfur must have an oxidation number of -2, making it essential to apply the rules of oxidation states to determine sulfur's charge in this compound.