What is the outcome of adding a strong acid to a solution that contains [Cu(NH3)4]2+?

What is the outcome of adding a strong acid to a solution that contains [Cu(NH3)4]2+?

• A. The concentration of ammonia increases
• B. The concentration of [Cu(NH3)4]2+ increases
• C. The concentration of [Cu(H2O)2(NH3)2]2+ increases
• D. The concentration of [Cu(NH3)4]2+ decreases

Answer: (D)

Adding a strong acid to a solution containing the complex ion [Cu(NH3)4]2+ results in a decrease in the concentration of that complex. This is primarily due to the fact that the strong acid, when introduced to the solution, releases a high concentration of hydrogen ions (H+). These hydrogen ions can interfere with the ammonia ligands (NH3) in the complex. The equilibrium of the complex can be described by the reaction: \[ \text{[Cu(NH}_3\text{)}_4]^{2+} \rightleftharpoons \text{Cu}^{2+} + 4\text{NH}_3 \] When you add the strong acid, the increase in H+ concentration leads to the partial protonation of ammonia, forming ammonium ions (NH4+). As the ammonia molecules are converted into ammonium ions, fewer ammonia ligands are available to coordinate with Cu2+, causing the equilibrium to shift to the left. This shift results in the dissociation of the [Cu(NH3)4]2+ complex back into free copper ions (Cu2+) and ammonia. Thus, the overall outcome is a decrease in the concentration of the [Cu(NH3

Adding a strong acid to a solution containing the complex ion [Cu(NH3)4]2+ results in a decrease in the concentration of that complex. This is primarily due to the fact that the strong acid, when introduced to the solution, releases a high concentration of hydrogen ions (H+). These hydrogen ions can interfere with the ammonia ligands (NH3) in the complex.

The equilibrium of the complex can be described by the reaction:

[ \text{[Cu(NH}_3\text{)}_4]^{2+} \rightleftharpoons \text{Cu}^{2+} + 4\text{NH}_3 ]

When you add the strong acid, the increase in H+ concentration leads to the partial protonation of ammonia, forming ammonium ions (NH4+). As the ammonia molecules are converted into ammonium ions, fewer ammonia ligands are available to coordinate with Cu2+, causing the equilibrium to shift to the left. This shift results in the dissociation of the [Cu(NH3)4]2+ complex back into free copper ions (Cu2+) and ammonia.

Thus, the overall outcome is a decrease in the concentration of the [Cu(NH3