# Kinetics equation of different equations:

```Kinetics equation of different equations:
1.zero order reaction:a reaction is said to be zero order reaction when the rate is
independent on the concentration of any reactant of the system.
Let : a=initial concentration of A in mole/liter
x=change in concentration at time t
a-x=concentration left at time t.
Examples of zero order reaction:
1.photochemical combination of H2 and Cl2 over water surface.
2.decomposition of NH3.
3.thermal decomposition of HI an a gold surface.
2.first order reaction :the reaction whose rate is determined by the change of only one
concentration term
Thus for a first order reaction the time taken to reduce the concentration to one half of its
original value is constant .
2.second order reaction:the reaction in which the reaction rate vis determined by the
variation of two concentration .two types of second order reaction are possible :
a-the rate is proportional to the square of the concentration of the same reactant or two
substance with the same concentration
b-the different concentration of the reactants
3.third order reaction :reactions whose rate is determined by the variation of three
concentration terms. Only a few third order reactions are definitely known. The simplest
case is
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