 This azeotrope has an approximate composition of 68% nitric acid and 32% water by mass, with a boiling point of .The term "azeotrope" is derived from the Greek words ζέειν (boil) and τρόπος (turning) with the prefix α- (no) to give the overall meaning, "no change on boiling".The term was coined in 1911 by English chemist John Wade and Richard William Merriman.