Cu\(^{2+}\)(aq) + 4NH\(_3\)(g) ↔ [Cu(NH\(_3\))\(_4\)]\(^{2+}\)(aq)
In the reaction above, what is the effect of precipitating Cu\(^{2+}\)(aq) as CuS(s)?
- NH3(g) concentration will decrease
- more NH3(g)
-
The equilibrium will shift to the right
- There will be no effect
The correct answer is: C
Explanation
The equilibrium will shift to the right. This is because when Cu\(^{2+}\) is precipitated as CuS, the concentration of Cu\(^{2+}\) in the solution decreases. According to Le Chatelier's principle, the equilibrium position will shift to the side that tends to restore the concentration of Cu\(^{2+}\) ions.
In this case, the equilibrium will shift to the right, favouring the formation of more [Cu(NH\(_3\))\(_4\)]\(^{2+}\) complex ions. This means that more NH\(_3\) molecules will be consumed to form the complex, but the concentration of NH\(_3\) will decrease, not increase.