make pure vs chemical science

make pure is not a noun while chemical science is a noun.

Word	Noun	Adjective	Verb	Adverb
make pure	No	No	Yes	No
chemical science	Yes	No	No	No

make pure (noun)	chemical science (noun)
	the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions

make pure (verb)	chemical science (verb)
remove impurities from, increase the concentration of, and separate through the process of distillation