Reactant Concentration for 1st Order Series Rxns is usually measured using the Mole per Cubic Meter[mol/m³] for Molar Concentration. Mole per Liter[mol/m³], Mole per Cubic Millimeter[mol/m³], Kilomole per Cubic Meter[mol/m³] are the few other units in which Reactant Concentration for 1st Order Series Rxns can be measured.