Why does equilibrium shift to the left when AgNO3 is added to the equation Co(H20)6 (aq) + 4Cl- (aq) <---> CoCl4 (aq) + 6H2o(l)?
Adding Ag^+ ppts the Cl^- as AgCl thereby removing Cl^- from the equation. Therefore the reaction will try to replace the Cl^- that has been removed and it does that by the reverse (shift to the left) reaction.
To understand why the addition of AgNO3 shifts the equilibrium to the left in the given equation, we need to consider the reaction that takes place between AgNO3 and Cl- ions.
AgNO3 (aq) → Ag+ (aq) + NO3- (aq)
When AgNO3 is added, it dissociates into Ag+ and NO3- ions. The Ag+ ions combine with Cl- ions to form a precipitate of AgCl, which reduces the concentration of Cl- ions in the solution. Since the Cl- ions are involved in the forward reaction of the equilibrium equation, reducing their concentration will shift the equilibrium to the left.
The Le Chatelier's principle explains this phenomenon. According to Le Chatelier's principle, a system at equilibrium will adjust to minimize the effect of any changes imposed on it. In this case, the addition of AgNO3 causes a decrease in the concentration of Cl- ions. To counteract this decrease, the equilibrium will shift towards the side where Cl- ions are being produced, which is the left side.
As a result, the equilibrium will shift to the left, favoring the reactants (Co(H2O)6 and 4Cl-) and reducing the formation of the product (CoCl4).
In summary, when AgNO3 is added, it reacts with Cl- ions to form a precipitate of AgCl, reducing the concentration of Cl- ions. Consequently, the equilibrium shifts to the left to restore the balance and counteract the decrease in Cl- concentration.
When AgNO3 is added to the equation Co(H2O)6 (aq) + 4Cl- (aq) ⇌ CoCl4 (aq) + 6H2O (l), the equilibrium shifts to the left. Let's break down why this happens step-by-step:
1. AgNO3 dissociates into Ag+ and NO3- ions in water:
AgNO3 (aq) → Ag+ (aq) + NO3- (aq)
2. The Ag+ ions react with the Cl- ions from the original equation to form a precipitate, AgCl:
Ag+ (aq) + Cl- (aq) → AgCl (s)
3. The formation of AgCl reduces the concentration of Cl- ions in the solution. According to Le Chatelier's principle, when one of the reactants is removed (in this case, Cl- ions), the equilibrium will shift in the direction that replenishes the reactants.
4. In order to restore the concentration of Cl- ions, the equilibrium shifts to the left, favoring the reactants. This means more Co(H2O)6 and Cl- ions will be formed, resulting in a decrease in the concentration of CoCl4 and H2O.
Therefore, the addition of AgNO3 pushes the equilibrium to the left, as the formation of AgCl reduces the concentration of Cl- ions, which causes the system to produce more reactants to restore the equilibrium.