Why does Le Chatelier's principle work?

2 Answers
Apr 3, 2018

Le Chatelier's principle works to relive stress on a system. The principle works to make a system more stable.


The laws of thermodynamics state that everything moves from order to disorder. Stack a bunch of blocks it creates an unstable system that will move to a more stable system by falling down.

If there is a greater concentrations of products than reactants this is a more order system than a balanced concentration of products and reactants. The system will move spontaneously to relieve the stress and move to a less order state. ( this is the second law of thermodynamics, the law of entropy disorder always increases)

Le Chatelier's principle works because a system will always move to relieve stress and move to a more disordered system.

Apr 3, 2018

See Below


The other answer is correct - Le Chatlier's principle works because the system is trying to relieve a stress. Let's look at the equilibrium constant, though.

#aA + bB = cC + dD#

#K_eq = ([C]^c[D]^d)/([A]^a[B^b])#
This is a constant. The K value will be a constant...which is why its called an equilibrium constant (assuming you don't mess with temperature).

So if I add a stress...like adding more of C....the the system is going to try to relieve that stress. But, if i have more C, #[C]^c# is too big, and the K value gets all messed up. So, D goes down and A goes up and B goes up, and with all these things going down and up, my larger value for C #[C]^c# is compensated for by a lower D and higher A and higher B....and K stays the same.