Given Le Chatelier's principle that says equilibrium will shift to maintain the ratio between products and reactants, how is a buffer physically possible?
If an ideal buffer would be one that has equal concentrations of acid/base and conjugate, wouldn't Le Chatelier's principle say that it would be impossible to maintain?
For example, if the dissolution equation for acetic acid is
#HC_2H_3O_2rarrH^++C_2H_3O_2^-#
then adding sodium acetate would increase the concentration of the acetate ion. Why doesn't the increase of product concentration cause them to convert back into reactants?
If an ideal buffer would be one that has equal concentrations of acid/base and conjugate, wouldn't Le Chatelier's principle say that it would be impossible to maintain?
For example, if the dissolution equation for acetic acid is
then adding sodium acetate would increase the concentration of the acetate ion. Why doesn't the increase of product concentration cause them to convert back into reactants?
1 Answer
Because that is not what Le Chatelier's principle maintains...
Explanation:
Le Chatelier's principle tells us that when a system at equilibrium is subjected to an external perturbation, the equilibrium will move so as to offset the external stress...
And
In your given example, you added sodium acetate to a system AT EQUILBRIUM....the equilibrium will move in the opposite direction, i.e. towards the water and acetic acid reactants as written...the equilibrium will still be maintained....
