stoichiometrical

 Of or pertaining to stoichiometry; employed in, or obtained by, stoichiometry.  [1913 Webster]

 of, pertaining to, using, or consuming, reagents in the exact proportions required for a given reaction; as, a stoichiometric reaction, i. e., a reaction which goes to completion, rather than stopping partway at an equilibrium point.  [PJC]