liquefaction vs state change

liquefaction and state change both are nouns.

Word	Noun	Adjective	Verb	Adverb
liquefaction	Yes	No	No	No
state change	Yes	No	No	No

As nouns, state change is a hypernym of liquefaction; that is, state change is a word with a broader meaning than liquefaction:

liquefaction: the conversion of a solid or a gas into a liquid
state change: a change from one state (solid or liquid or gas) to another without a change in chemical composition

Other hypernyms of liquefaction include phase change, phase transition, physical change.

liquefaction (noun)	state change (noun)
the conversion of a solid or a gas into a liquid	a change from one state (solid or liquid or gas) to another without a change in chemical composition