national capital vs Rangoon

national capital and Rangoon both are nouns.

Word	Noun	Adjective	Verb	Adverb
national capital	Yes	No	No	No
Rangoon	Yes	No	No	No

national capital (noun)	Rangoon (noun)
the capital city of a nation	the former capital and largest city of Myanmar; located in the south near the Irrawaddy river delta