All chemical reactions use reactants in a specific proportion or stoichiometry to regulate the amount of products produced. The reactant is consumed completely during the reaction but some of the reactant is left over.

In order for a high temperature boiler or steam engine to produce superheated water, or steam: the heat source must be greater than 100°c the water must be permitted to evaporate quickly the system must be sealed and become pressurized above atmospheric pressure the vapor pressure must be kept below 760 mm(hg)