white arsenic vs arsenous anhydride

white arsenic and arsenous anhydride both are nouns.

Word	Noun	Adjective	Verb	Adverb
white arsenic	Yes	No	No	No
arsenous anhydride	Yes	No	No	No

As nouns, white arsenic and arsenous anhydride are synonyms defined as:

white arsenic and arsenous anhydride: a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer

Other synonyms of white arsenic include arsenic, arsenic trioxide, arsenous oxide, ratsbane.

white arsenic (noun)	arsenous anhydride (noun)
a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer	a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer