sodium nitrite vs nitrite

sodium nitrite and nitrite both are nouns.

Word	Noun	Adjective	Verb	Adverb
sodium nitrite	Yes	No	No	No
nitrite	Yes	No	No	No

As nouns, nitrite is a hypernym of sodium nitrite; that is, nitrite is a word with a broader meaning than sodium nitrite:

sodium nitrite: nitrite used to preserve and color food especially in meat and fish products; implicated in the formation of suspected carcinogens
nitrite: the radical -NO2 or any compound containing it (such as a salt or ester of nitrous acid)

sodium nitrite (noun)	nitrite (noun)
nitrite used to preserve and color food especially in meat and fish products; implicated in the formation of suspected carcinogens	the radical -NO2 or any compound containing it (such as a salt or ester of nitrous acid)