exchangeable vs exchangeability

exchangeable is not a noun while exchangeability is a noun.

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

exchangeable (noun)	exchangeability (noun)
	the quality of being capable of exchange or interchange

exchangeable (adjective)	exchangeability (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