Do you recognize this chemical? What do you call it? The vernacular name for it is copper sulfate, but it also goes by the common name of copper(II) sulfate or cupric sulfate or the archaic name blue vitriol or bluestone. Its systematic or IUPAC name is copper(II) sulfate pentahydrate. Do you know the difference between the various types of chemical names and when you might expect to hear them applied to a substance? Here's what you need to know.