Air & Water Quality Glossary Oxidize / Oxidant Oxidize means to chemically increase the valence(combining capacity) of a molecule by the release of electrons. The chemical used to created the oxidation is called the oxidant. The valance change may or may not cause a precipitate. In the case of iron (Fe), Fe (II) is converted to the precipitate Fe(III). In the case of arsenic( As), As(III) is converted to As(V) with no precipitation. Examples: When iron is oxidized, it forms a solid (precipitate) we call rust. The precipitate is then filtered out of the water. In a washing machine, the water gets mixed with oxygen from the air along with bleach. The air and bleach cause the iron in the water to be oxidized(turned to rust). The clothes then act as the filter and remove the rust. The rust causes the orange stain on the clothes. Previous Page Home | Top of page | Contact © Copyright 2000, Air & Water Quality, Inc. Maine's Water Experts