Half life of first order:

Time required to consume the half of initial concentration of reactant is called half life period.

At half life time:

Thus half life period is independent of initial concentration.

Unit of rate constant is time-1.

Reciprocal of rate const. (half life) is average life.

After ‘n’ half times the concentration A= A0/2n


T75 = 2 ´ t50. i.e. time  taken to complete 75 % of reaction is twice that of half life time.

Examples of First Order Reactions:

Half life of Nth Order Reaction:
For nth order reaction the mathematical expression:

Chemical Kinetics of population growth:

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Class 12 Chemistry Chemical Kinetics All Topics Notes CBSE Class 12 Chemistry All Chapters Notes

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