effectualness vs efficacious

effectualness is a noun but efficacious is not a noun.

Word	Noun	Adjective	Verb	Adverb
effectualness	Yes	No	No	No
efficacious	No	Yes	No	No

effectualness (noun)	efficacious (noun)
power to be effective; the quality of being able to bring about an effect

effectualness (adjective)	efficacious (adjective)
	marked by qualities giving the power to produce an intended effect
	producing or capable of producing an intended result or having a striking effect