##  [Reaction Rate Constant](/reaction-rate-constant) 

  ##  [Reaction Rate Constant](https://natural.quantumdictionary.io/reaction-rate-constant-0) 

  

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**Natural & Formal Sciences Dictionary**

 







 

 

 

 



 

 

 

 

Definition

A proportionality constant k in a chemical rate law that relates reactant concentrations (or activities) to the instantaneous rate of an elementary or effective reaction step under specified conditions.