what is le chateliers principle.....??

Dear student!

The Le Chetelier's Principle simply explains that, if a dynamic equilibrium is disturbed by changing the conditions or parameters, the position of equilibrium will tend to shift in such direction which overcomes the change.

According to Le Chatelier's principle, if a change or disturbance is imposed on a system at equilibrium, the equilibrium will shift to minimize the change. 

These disturbances include: Change in temperature ,change in pressure/volume (for gases) or change in concentration 

A simple example of this: 
N₂ (g) + 3H₂ (g) ⇌ 2 NH₃ (g) ΔH = −92kJ/mol 

If we add N₂ (g) or 3H₂ (g) the equilibrium will shift to the right (to the products), and more NH₃ (g) will be created so as to minimize the stress. 

If we add NH₃(g), the equilibrium will shift to the left (to the reactants), and more N₂ (g) and H₂(g) will be created.