Which of the following is not a chelating agent :

Options

A. Oxalo
B. thiosulphato
C. Glycinato
D. Ethylene

Answer

To determine which of the following is not a chelating agent, we need to understand the concept of chelating agents and ligands.

### Step-by-Step Solution:

1. **Define Chelating Agents**: Chelating agents are molecules that can bind to a central metal atom or ion to form a coordinate complex. This binding occurs through multiple points of attachment, allowing the formation of stable ring structures.

2. **Understand Ligands**: A ligand is a molecule that donates a pair of electrons to a metal ion to form a coordinate bond. Ligands can be classified based on the number of donor atoms they possess:
- **Monodentate Ligands**: These ligands have one donor atom and can bind to the metal at a single point.
- **Bidentate Ligands**: These ligands have two donor atoms and can bind to the metal at two points, allowing for the formation of chelate rings.

3. **Identify the Options**: The question provides a list of compounds, among which we need to identify the one that is not a chelating agent.

4. **Analyze Each Option**:
- **Oxaloacetate**: This is a bidentate ligand and can form chelate rings.
- **Glycinate**: This is also a bidentate ligand and can form chelate rings.
- **Ethylenediamine**: This is another bidentate ligand capable of forming chelate rings.
- **Thiosulphate**: This is a monodentate ligand, meaning it can only bind at one point and cannot form chelate rings.

5. **Conclusion**: Since thiosulphate is a monodentate ligand and cannot form chelate rings, it is not a chelating agent. Therefore, the answer to the question is **Thiosulphate**.

### Final Answer: Thiosulphate is not a chelating agent.

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