posted by L .
if NaCl is added to this equation:
[Co(OH2)6]2+ + 4 Cl- + heat ->(supposed to be double arrow) [CoCl4]2- + 6 H2O
would the equilibrium shift right or left? also same question for the addition of AgNO3.
Remember Le Chatelier's Principle. When a system at equilibrium is subjected to a stress, the reaction will shift in a direction to relieve the stress.
So, if we ADD NaCl to the reaction at equilibrium, it will shift (to the right or to the left) so as to use up the Cl^- added. How can it do that. If it shifts to the right, the Cl^- is used up. If it shifts to the left, Cl^- is formed. So which will it do?
If AgNO3 is added, what will happen? Remember that AgNO3 reacts with NaCl to form a solid, AgCl. So the AgNO3 will REMOVE Cl^- from solution (by forming the insoluble ppt of AgCl) and the reaction then must shift (again, right or left) so as to try to replace the Cl^- that has been removed. Which way will that be?