Question

According to Le Chatelier's Principle: What happens when you add DIFFERENT species to the equilibrium?

Answer 1

Answer:

Le Chatelier's principle applies to equilibrium concentrations in specific equilibria. Addition of different species that affect these equilibrium concentrations, will change the equilibria accordingly.

Explanation:

Consider the solution behaviour of a sparingly soluble or insoluble salt at equilibrium, say  AgCl

.We write  

AgCl(s)⇌Ag+  +Cl−

(i)  To describe this reaction, we write  Ksp=[Ag+][CI−]

. Should we add aqueous ammonia we will reduce the  [Ag+]

value because of the following competing equiibrium:

Ag+  +2NH3⇌[Ag(NH3)2]+

(ii)  More silver ion,  [Ag+]

, will enter solution because it can be complexed by the ammonia. To give an answer in terms of Le Chatelier's principle, because we reduce  [Ag+]

in equilibrium (i), we can drive the equilibrium to the right hand side.

On the other hand, for equilibrium (ii), if we reduce  [NH3]

, say by increasing the  pHto form  NH+4

we would drive the equilibrium to the left. Of course, we are dealing with competing equilibria, that may be difficult to calculate.