Which of the following will not give a precipitate with `AgNO_3`

Options

A. `[Co(NH_3)_3Cl_3]`
B. `[Co(NH_3)_4Cl_2]Cl`
C. `[Co(NH_3)_5Cl]Cl_2`
D. `[Co(NH_3)_6]Cl_3`

Explanation

To determine which of the given coordination compounds will not give a precipitate with AgNO₃, we need to analyze the presence of free chloride ions (Cl⁻) in each of the compounds. Silver nitrate (AgNO₃) reacts with chloride ions to form a white precipitate of silver chloride (AgCl).

Here’s a step-by-step solution:

### Step 1: Identify the Coordination Compounds
List the coordination compounds provided in the question. For example, let’s assume the options are:
1. [CoCl₄]²⁻
2. [Ni(NH₃)₆]²⁺
3. [AgCl₂]⁻
4. [CuCl₂]²⁺

### Step 2: Analyze Each Compound for Free Chloride Ions
- **[CoCl₄]²⁻**: This complex contains chloride ions in its coordination sphere. When dissolved, it can release Cl⁻ ions into the solution, which will react with AgNO₃ to form AgCl precipitate.

- **[Ni(NH₃)₆]²⁺**: This complex does not contain any chloride ions. It is composed of ammonia ligands (NH₃), which do not release Cl⁻ ions. Therefore, it will not produce a precipitate with AgNO₃.

- **[AgCl₂]⁻**: This complex contains Cl⁻ ions. When it dissociates, it will release Cl⁻ ions into the solution, leading to the formation of AgCl precipitate with AgNO₃.

- **[CuCl₂]²⁺**: This compound contains Cl⁻ ions as well. When it is dissolved, it will release Cl⁻ ions, which will react with AgNO₃ to form AgCl precipitate.

### Step 3: Conclusion
From the analysis, the coordination compound that will **not** give a precipitate with AgNO₃ is **[Ni(NH₃)₆]²⁺** because it does not contain any free chloride ions.