acid vs acidity

acid and acidity both are nouns.

Word	Noun	Adjective	Verb	Adverb
acid	Yes	Yes	No	No
acidity	Yes	No	No	No

acid (noun)	acidity (noun)
street name for lysergic acid diethylamide	pH values below 7
any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt	the property of being acidic
	the taste experience when something acidic is taken into the mouth

acid (adjective)	acidity (adjective)
having the characteristics of an acid
being sour to the taste
harsh or corrosive in tone