Here how many ligands are ambidentate?
`CN^(-), ONO^(-), S_(2)O_(3)^(2-), CNO, C_(2)O_(4)^(2-), CH_(3)COO^(-) en`

Answer

To determine how many ligands are ambidentate from the given list, we need to analyze each ligand based on its ability to coordinate to a central atom through more than one atom.

### Step-by-Step Solution:

1. **Identify Ambidentate Ligands**:
- An ambidentate ligand is one that can coordinate to a metal center through two different atoms.

2. **Evaluate Each Ligand**:
- **CN⁻ (Cyanide Ion)**:
- The cyanide ion can coordinate through either the carbon atom or the nitrogen atom. Thus, it is an ambidentate ligand.
- **ONO⁻ (Nitrito Ion)**:
- The nitrito ion can coordinate through either the nitrogen atom or one of the oxygen atoms. Therefore, it is also an ambidentate ligand.
- **S₂O₃²⁻ (Thiosulfate Ion)**:
- The thiosulfate ion has two donor atoms (sulfur and oxygen) but coordinates through both simultaneously, making it a bidentate ligand, not ambidentate.
- **CNO⁻ (Cyanato Ion)**:
- The cyanato ion can coordinate through either the carbon atom or the nitrogen atom, making it an ambidentate ligand.
- **C₂O₄²⁻ (Oxalate Ion)**:
- The oxalate ion has two donor atoms (both oxygens) and coordinates through both simultaneously, classifying it as a bidentate ligand.
- **CH₃COO⁻ (Acetate Ion)**:
- The acetate ion can only coordinate through the oxygen atom, making it a monodentate ligand.
- **en (Ethylene Diamine)**:
- Ethylene diamine has two donor atoms (both nitrogens) and coordinates through both, classifying it as a bidentate ligand.

3. **Count the Ambidentate Ligands**:
- From the analysis, the ambidentate ligands identified are:
- CN⁻
- ONO⁻
- CNO⁻
- Therefore, there are **three ambidentate ligands** in total.

### Final Answer:
There are **3 ambidentate ligands**: CN⁻, ONO⁻, and CNO⁻.

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