*Transition state theory or Activated complex theory *

*Transition state theory or Activated complex theory*

It is more modern theory proposed in 1932 by Pelzer & Manger later developed by Erying and colleagues.

1. Rate equation formation using the statistical mechanics to describe equilibrium between activated complex and reactant.

2. Rate equation formulation as per thermodynamical state function to describe transition state complex and reactant.

3. And rate equation ‘s statistical mechanical derivation.

1. Rate equation formation using the statistical mechanics to describe equilibrium between activated complex and reactant.

2. Rate equation formulation as per thermodynamical state function to describe transition state complex and reactant.

3. And rate equation ‘s statistical mechanical derivation.

Various postulates of Transition state theory or Activated complex theory are……

1. For any chemistry reaction to take place, it requires reactant have sufficient minimum energy. So it forms activated complex and reactant & complex are in equilibrium.

Reactant <~> [ activated complex ]

2. Activated complex have normal molecule with 4th degree of freedom along chemistry reaction coordinate.

3. And activated complex decompose along this 4th degree of freedom to yield products.

[Activated complex ] <~> Product

Overall,

Transition state theory or Activated complex theory postulates says…

1. For any chemistry reaction to take place, it requires reactant have sufficient minimum energy. So it forms activated complex and reactant & complex are in equilibrium.

Reactant <~> [ activated complex ]

2. Activated complex have normal molecule with 4th degree of freedom along chemistry reaction coordinate.

3. And activated complex decompose along this 4th degree of freedom to yield products.

[Activated complex ] <~> Product

Overall,

Transition state theory or Activated complex theory postulates says…

Reactant <~> [activated complex] <~> Product

Rate of reaction = decomposition rate of activated complex

Then,

rate of reaction = probability of crossing energy barriers * concentration of activated complex at top of energy barrier * frequency of crossing energy barrier

rate of reaction = probability of crossing energy barriers * concentration of activated complex at top of energy barrier * frequency of crossing energy barrier