pesticide vs chemical

pesticide and chemical both are nouns.

Word	Noun	Adjective	Verb	Adverb
pesticide	Yes	No	No	No
chemical	Yes	Yes	No	No

As nouns, chemical is a hypernym of pesticide; that is, chemical is a word with a broader meaning than pesticide:

pesticide: a chemical used to kill pests (as rodents or insects)
chemical: material produced by or used in a reaction involving changes in atoms or molecules

Other hypernyms of pesticide include chemical substance.

pesticide (noun)	chemical (noun)
a chemical used to kill pests (as rodents or insects)	material produced by or used in a reaction involving changes in atoms or molecules

pesticide (adjective)	chemical (adjective)
	relating to or used in chemistry
	of or made from or using substances produced by or used in reactions involving atomic or molecular changes