Water

Water uses Domestic : drinking , cooking , washing , cleaning Industry : solvent for many chemicals and as a coolant to stop industrial chemical reactions from over heating. As a cheap reactant in many Chemical reactions used for manufacture of useful chemical products Generating electricity by running turbines
Testing for Water Chemical test using the reaction between water and the anhydrous salt(has no water) called Cobalt Chloride or Copper (II) sulfate , since both of these salts have differenct colors when they are anhydrous and when they contain water of crystallization (are hydrated)