alkane series vs C2H6

alkane series and C2H6 both are nouns.

Word	Noun	Adjective	Verb	Adverb
alkane series	Yes	No	No	No
C2H6	Yes	No	No	No

As nouns, C2H6 is a hyponym of alkane series; that is, C2H6 is a word with a more specific, narrower meaning than alkane series:

alkane series: a series of non-aromatic saturated hydrocarbons with the general formula CnH(2n+2)
C2H6: a colorless odorless alkane gas used as fuel

Other hyponyms of alkane series include butane, amine, aminoalkane, ethane, heptane, hexane, methane.

alkane series (noun)	C2H6 (noun)
a series of non-aromatic saturated hydrocarbons with the general formula CnH(2n+2)	a colorless odorless alkane gas used as fuel