mountain chain vs range of mountains

mountain chain and range of mountains both are nouns.

Word	Noun	Adjective	Verb	Adverb
mountain chain	Yes	No	No	No
range of mountains	Yes	No	No	No

As nouns, mountain chain and range of mountains are synonyms defined as:

Other synonyms of mountain chain include chain, chain of mountains, mountain range, range.

mountain chain (noun)	range of mountains (noun)
a series of hills or mountains	a series of hills or mountains