convertibility vs exchangeable

convertibility is a noun but exchangeable is not a noun.

Word	Noun	Adjective	Verb	Adverb
convertibility	Yes	No	No	No
exchangeable	No	Yes	No	No

convertibility (noun)	exchangeable (noun)
the quality of being exchangeable (especially the ability to convert a currency into gold or other currencies without restriction)

convertibility (adjective)	exchangeable (adjective)
	suitable to be exchanged
	capable of being exchanged for or replaced by something of equal value
	capable of replacing or changing places with something else; permitting mutual substitution without loss of function or suitability