What does manganous mean?
Manganous is a technical adjective used in chemistry for compounds or ions containing manganese in the +2 oxidation state. The term belongs to an older naming convention in which the ending “-ous” distinguished lower oxidation states from related “-ic” forms; thus, manganous means manganese(II), while manganic refers to manganese(III). It is not simply a general synonym for “containing manganese,” because the oxidation state is an essential part of the meaning. Manganous compounds include manganous oxide, manganous sulfate, and manganous chloride. Although systematic chemical names increasingly use manganese(II) directly, manganous remains familiar in technical chemistry, materials science, and descriptions of inorganic compounds. The word is useful for recognizing and comparing different manganese species, particularly when discussing chemical reactions, oxidation states, or the composition of industrial and laboratory materials.
adjectiveDenoting a compound or ion containing manganese in the +2 oxidation state, also called manganese(II).
- Containing manganese in the +2 oxidation state.
"Manganous sulfate is sometimes used as a source of manganese in animal feed."
"Manganous sulfate is sometimes used as a source of manganese in animal feed."
"Manganous oxide can be prepared by heating manganese compounds in an oxygen-free atmosphere."
The “-ous” ending in manganous does not merely mean “containing manganese”; it specifically identifies the +2 oxidation state.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does manganous come from?
Manganous was formed in English from manganese with the chemical suffix “-ous,” used here to designate a particular oxidation state. The adjective belongs to the same chemical word family as manganese, manganic, and manganate, all of which share the manganese root. Its formation reflects a historical naming system in which contrasting endings distinguished oxidation states before modern numerical nomenclature became standard.
Related word forms
How manganous is actually used
This is specialized chemical terminology. In modern systematic nomenclature, manganese(II) is often preferred, but manganous remains established in names such as manganous oxide and manganous sulfate.
Easily confused with manganous
Manganous denotes manganese in the +2 oxidation state, whereas manganic denotes manganese in the +3 oxidation state.