soda ash vs washing soda

soda ash and washing soda both are nouns.

Word	Noun	Adjective	Verb	Adverb
soda ash	Yes	No	No	No
washing soda	Yes	No	No	No

As nouns, soda ash and washing soda are synonyms defined as:

soda ash and washing soda: a sodium salt of carbonic acid; used in making soap powders and glass and paper

Other synonyms of soda ash include sal soda, soda, sodium carbonate.

soda ash (noun)	washing soda (noun)
a sodium salt of carbonic acid; used in making soap powders and glass and paper	a sodium salt of carbonic acid; used in making soap powders and glass and paper