What is Le Chatelier principle?

Le Chatelier’s principle

According to this principle, if a system is in equilibrium and it is subjected to any change in any of the factors that determine the equilibrium conditions of the system, then it will shift the equilibrium in such a way so as to reduce or to counteract the effect of the change.

The factors which affect equilibrium are:

1. The concentration of reactants and products

2. Temperature

3. Pressure

4. Presence of catalysts

^Example

^{Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction:}

(i) Increasing the pressure 

^{According to Le Chatelier’s principle, the equilibrium will shift in the backward direction.} 

(ii) Increasing the temperature 

According to Le Chatelier’s principle, as the reaction is endothermic, the equilibrium will shift in the forward direction. 

(iii) Using a catalyst 

The equilibrium of the reaction is not affected by the presence of a catalyst. A catalyst only increases the rate of a reaction. Thus, equilibrium will be attained quickly.