azo group vs chemical group

azo group and chemical group both are nouns.

Word	Noun	Adjective	Verb	Adverb
azo group	Yes	No	No	No
chemical group	Yes	No	No	No

As nouns, chemical group is a hypernym of azo group; that is, chemical group is a word with a broader meaning than azo group:

azo group: the bivalent group -N=N- united to two hydrocarbon groups
chemical group: (chemistry) two or more atoms bound together as a single unit and forming part of a molecule

Other hypernyms of azo group include group, radical.

azo group (noun)	chemical group (noun)
the bivalent group -N=N- united to two hydrocarbon groups	(chemistry) two or more atoms bound together as a single unit and forming part of a molecule