How many of the following are bidentate ligan?
Oxalate, Glycinate, Hydrazine, Xyanide, Acetylacetonate, Diethylenetriamine, `dmg^(ɵ)`, ammonia, sulphate, water.

Options

A. (a) 4
B. (b) 3
C. (c) 7
D. (d) 5

Explanation

To determine how many of the given ligands are bidentate ligands, we will analyze each ligand based on its structure and donor sites. A bidentate ligand has two donor atoms that can coordinate to a metal center.

### Step-by-Step Solution:

1. **Oxalate (C2O4^2-)**:
- The oxalate ion has two carboxylate groups (-COO^-) that can donate electrons.
- **Conclusion**: Oxalate is a bidentate ligand.

2. **Glycinate (NH2CH2COO^-)**:
- Glycinate has an amino group (NH2) and a carboxylate group (COO^-).
- **Conclusion**: Glycinate is a bidentate ligand.

3. **Hydrazine (NH2NH2)**:
- Hydrazine has two amine groups but can only donate one pair of electrons at a time.
- **Conclusion**: Hydrazine is a monodentate ligand.

4. **Cyanide (CN^-)**:
- Cyanide has one donor site (the carbon atom).
- **Conclusion**: Cyanide is a monodentate ligand.

5. **Acetylacetonate (C5H7O2^-)**:
- Acetylacetonate has two keto groups that can donate electrons.
- **Conclusion**: Acetylacetonate is a bidentate ligand.

6. **Diethylenetriamine (C4H11N3)**:
- Diethylenetriamine has three amine groups and can coordinate through all three.
- **Conclusion**: Diethylenetriamine is a tridentate ligand.

7. **Dimethylglyoxime (DMG)**:
- DMG has two nitrogen donor sites that can coordinate to a metal.
- **Conclusion**: DMG is a bidentate ligand.

8. **Ammonia (NH3)**:
- Ammonia has one donor site (the nitrogen atom).
- **Conclusion**: Ammonia is a monodentate ligand.

9. **Sulphate (SO4^2-)**:
- Sulphate can act as a bidentate ligand, but typically it is considered a monodentate ligand in coordination chemistry.
- **Conclusion**: Sulphate is generally treated as a monodentate ligand.

10. **Water (H2O)**:
- Water has one donor site (the oxygen atom).
- **Conclusion**: Water is a monodentate ligand.

### Summary of Bidentate Ligands:
- **Bidentate Ligands**: Oxalate, Glycinate, Acetylacetonate, DMG.
- **Total Count of Bidentate Ligands**: 4

### Final Answer:
There are **4 bidentate ligands** among the given options.

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