What is the Difference Between Reaction Rate and Rate Constant?

The difference between reaction rate and rate constant can be summarized as follows:

• Reaction Rate (R): The reaction rate, also known as the rate law, is the change in the concentration of a reactant or product in a unit of time. It depends on factors such as the concentration of reactants, catalyst, and temperature. The unit of reaction rate varies depending on the state of the reactants: in the liquid state, it is typically expressed in M/s, while in the gaseous state, it is expressed in mL/mol·s.
• Rate Constant (K): The rate constant is a specific value for a chemical reaction under defined conditions, and it is the proportionality constant relating the rate of the reaction to the concentrations of reactants. It is independent of the concentration of reactants and depends on temperature. The value of the rate constant is temperature-dependent, with a large value indicating a relatively fast reaction and a small value indicating a relatively slow reaction.

In summary, the reaction rate is the speed at which a chemical reaction takes place and depends on factors such as reactant concentration and temperature, while the rate constant is a specific value for a reaction under defined conditions that relates the reaction rate to the concentrations of reactants.

Comparative Table: Reaction Rate vs Rate Constant

The reaction rate and rate constant are two important concepts in chemical kinetics. Here is a table highlighting the differences between them:

To summarize, the reaction rate is a measure of how fast reactants combine or products are formed, while the rate constant is a proportionality constant that describes the reaction rate under specific experimental conditions.