Rate constant for Zero Order Rxn is the 1st step where the value of Rate Constant is Obtained. And is denoted by k0. Rate Constant for Zero Order Rxn is usually measured using the Mole per Cubic Meter Second for Reaction Rate. Note that the value of Rate Constant for Zero Order Rxn is always positive. Typically, the value of Rate Constant for Zero Order Rxn is greater than 0.