effectual vs effectiveness

effectual is not a noun while effectiveness is a noun.

Word	Noun	Adjective	Verb	Adverb
effectual	No	Yes	No	No
effectiveness	Yes	No	No	No

effectual (noun)	effectiveness (noun)
	power to be effective; the quality of being able to bring about an effect
	capacity to produce strong physiological or chemical effects

effectual (adjective)	effectiveness (adjective)
producing or capable of producing an intended result or having a striking effect
having legal efficacy or force