The co-ordination number of Ni in the complex `[Ni(EDTA)]^(-2)` is

Options

A. 1
B. 2
C. 3
D. 6

Explanation

To determine the coordination number of nickel in the complex \([Ni(EDTA)]^{-2}\), we can follow these steps:

### Step 1: Understand Coordination Number
The coordination number of a metal ion in a coordination complex is defined as the number of atoms (from ligands) that are directly bonded to the metal ion.

**Hint:** Remember that coordination number is specific to the metal ion and is determined by the number of bonds formed with ligands.

### Step 2: Identify the Ligand
In this case, the ligand is EDTA (ethylenediaminetetraacetic acid). It is important to know the type of ligand involved in the complex.

**Hint:** Look for the nature of the ligand; it can be monodentate, bidentate, or polydentate.

### Step 3: Determine the Denticity of EDTA
EDTA is a hexadentate ligand, which means it can form six bonds with the metal ion. This is due to the presence of four carboxylate groups and two amine groups in its structure.

**Hint:** Hexadentate ligands can attach to the metal ion at six different points.

### Step 4: Count the Bonds
When EDTA coordinates with nickel, it forms six bonds. Each of the six donor atoms from the EDTA ligand will bond with the nickel ion.

**Hint:** Visualize or draw the structure of the complex to see how many atoms are directly bonded to the metal.

### Step 5: Conclusion
Since EDTA forms six bonds with nickel, the coordination number of nickel in the complex \([Ni(EDTA)]^{-2}\) is 6.

**Final Answer:** The coordination number of Ni in the complex \([Ni(EDTA)]^{-2}\) is **6**.

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