Question

Identify the ionization isomer of \([\text{Cr}(\text{H}_2\text{O})_4\,\text{Cl}(\text{NO}_2)]\,\text{Cl}\) from the following.

• A. \([\text{Cr}(\text{H}_2\text{O})_4\,(\text{O}_2\text{N})]\,\text{Cl}_2\)
• B. \([\text{Cr}(\text{H}_2\text{O})_4\,\text{Cl}_2]\,(\text{NO}_2)\)
• C. \([\text{Cr}(\text{H}_2\text{O})_4\,\text{Cl}(\text{ONO})]\,\text{Cl}\)
• D. \([\text{Cr}(\text{H}_2\text{O})_4\,\text{Cl}_2(\text{NO}_2)]\,\text{H}_2\text{O}\)

Hint:

Ionization isomers swap an ion between the coordination sphere and the counter ion.

Answer 1

The Correct Option is B

Step 1: Check formulas
Parent: $Cr, 4 H_2O, 2 Cl, 1 NO_2$. Option B: $Cr, 4 H_2O, 2 Cl, 1 NO_2$ in a different split.

Step 2: Ions
Parent gives $Cl^-$ in solution; option B gives $NO_2^-$ in solution. Same atoms, different ions, which is ionization isomerism.

Final Answer:
Option B. \[ \boxed{\text{(B)}\ [Cr(H_2O)_4Cl_2]NO_2} \]