Question

In the complex K[Cr(H₂O)₂(C₂O₄)₂], Central metal ion is                and               . 

Hint:

In coordination complexes, the oxidation state is determined by solving the charge balance equation, and the coordination number is counted based on the number of donor atoms.

Answer 1

Step 1: Identify the Oxidation State of Chromium 
- The given complex is K[Cr(H₂O)₂(C₂O₄)₂].
- Potassium (K⁺) has a charge of +1.
- The ligands are:

H₂O (Water): Neutral ligand (charge = 0).

C₂O₄^2- (Oxalate): Bidentate ligand (charge = -2 each).

Step 2: Oxidation State Calculation 
\[ +1 + x + 2(0) + 2(-2) = 0 \] \[ x - 4 + 1 = 0 \] \[ x = +3 \] So, the oxidation state of Chromium (Cr) is +3. 
Step 3: Coordination Number of Chromium 
- H₂O (Water) is a monodentate ligand (2 × 1 = 2).
- C₂O₄^2- (Oxalate) is a bidentate ligand (2 × 2 = 4).
- Total coordination number: \[ 2 + 4 = 6 \] So, the coordination number of Chromium is 6. 
Step 4: Conclusion 
- The central metal ion is Cr³⁺.
- The coordination number is 6.