Module 2-Chemical Kinetics.pdf
07 Dec 2022
The branch of Physical chemistry which deals with the rate of reactions or the Kinetics of Chemical reactions is called Chemical Kinetics.
RATE OF A REACTION: The rate of reaction is defined as the change in concentration of any of reactant or products per unit time.
For a chemical reaction, there are many ways to express the reaction rate. 01)Average rate of Reaction 02)Instantaneous rate of Reaction
01)Average Rate of Reaction:It is defined as the ratio of change in concentration of reactants or products to the change in a time interval of a chemical reaction.
02)Instantaneous Rate of Reaction:
RATE LAW:It is an expression that tells the rate of a reaction. It is also called rate equation.
**LAW OF MASS ACTION:**Law of mass action is the equation which represents the ratio between the masses of products and reactants which are raised to the power of their stoichiometric coefficient.
| RATE LAW | LAW OF MASS ACTION |
|---|---|
| It is an expression that tells the rate of a reaction. | It is an equation which represents the ratio between the masses of products and masses of reactants whose power is raised according to their stoichiometric coefficients. |
| Eg:Findig k equilibrium constant. | |
| Concentrations of reactants are raised to powers which may or may not be equal to the stoichiometric coefficient of the reaction. It is experimental data. | Concentrations of reactants are raised to powers of the stoichiometric coefficient of the reaction. It is a theoretical concept. |
| Gives the rate of a particular reaction. | Gives the favouring direction in which reaction will proceed. |
| Products of a reaction are not included in the expression | Products of a reaction are included in the expression |
| A proportionality constant (k)(k) is used | A proportionality constant (k)(k) is not used. |
ORDER OF REACTION:
MOLECULARITY OF REACTION: