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The total number of ions produced from the complex \( [Cr(NH_3)_6]Cl_3 \) in aqueous solution will be?

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When a coordination complex dissociates in water, the total number of ions is equal to the sum of the ions produced from the complex and its counterions (such as \( Cl^- \) or other anions).
Updated On: Mar 27, 2026
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The Correct Option is B

Solution and Explanation

Determine the total number of ions generated from the dissociation of \( [Cr(NH_3)_6]Cl_3 \) in an aqueous environment.
The complex in question is \( [Cr(NH_3)_6]Cl_3 \). This compound comprises a central chromium ion, \( Cr^{3+} \), bonded to six ammonia molecules (\( NH_3 \)) and three chloride ions (\( Cl^- \)) as counterions. 
Step 1: Dissolution Process 
Upon introduction to water, \( [Cr(NH_3)_6]Cl_3 \) dissociates. The chemical equation for this dissociation is: \[ [Cr(NH_3)_6]Cl_3 \rightarrow [Cr(NH_3)_6]^{3+} + 3Cl^- \] In this equation: 
- \( [Cr(NH_3)_6]^{3+} \) represents the complex ion. 
- The 3 \( Cl^- \) entities are the counterions. 
Step 2: Ion Count 
The dissociation yields the following ions: 
- One \( [Cr(NH_3)_6]^{3+} \) ion. 
- Three \( Cl^- \) ions. Therefore, the cumulative count of ions produced is calculated as: \[ 1 \, \text{(complex ion)} + 3 \, \text{(chloride ions)} = 6 \, \text{ions} \] Summary: 
The complete dissociation of \( [Cr(NH_3)_6]Cl_3 \) in water results in the formation of 6 ions.

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