Identify the correct statements for the behaviour of ethane-1, 2-diamine as a ligand.

Options

A. It is a neutral ligand
B. It is a didentate ligand
C. It is a chelating ligand
D. It is a unidentate ligand

Explanation

To solve the question regarding the behavior of ethane-1,2-diamine as a ligand, we will analyze each statement provided in the options.

### Step-by-Step Solution:

1. **Understanding the Structure of Ethane-1,2-diamine**:
- Ethane-1,2-diamine has the chemical formula NH2CH2CH2NH2.
- It contains two amine (-NH2) groups attached to a two-carbon chain.

**Hint**: Draw the structure of ethane-1,2-diamine to visualize the donor sites.

2. **Identifying the Type of Ligand**:
- A ligand can be classified based on the number of donor atoms it has.
- Ethane-1,2-diamine has two nitrogen atoms that can donate lone pairs to a metal ion.

**Hint**: Remember that a bidentate ligand has two donor sites.

3. **Analyzing Each Statement**:
- **Statement 1**: "It is a neutral ligand."
- Ethane-1,2-diamine does not carry any overall charge, making it a neutral ligand.
- **Conclusion**: This statement is **correct**.

- **Statement 2**: "It is a bidentate ligand."
- Since it has two nitrogen atoms that can each donate a lone pair, it qualifies as a bidentate ligand.
- **Conclusion**: This statement is **correct**.

- **Statement 3**: "It is a chelating ligand."
- A chelating ligand forms a ring structure with a metal ion. Ethane-1,2-diamine can form a five-membered ring with a metal ion by coordinating through both nitrogen atoms.
- **Conclusion**: This statement is **correct**.

- **Statement 4**: "It is a unidentate ligand."
- A unidentate ligand has only one donor site. Since ethane-1,2-diamine has two donor sites, it cannot be classified as unidentate.
- **Conclusion**: This statement is **incorrect**.

4. **Final Answer**:
- The correct statements about ethane-1,2-diamine as a ligand are:
- 1. It is a neutral ligand.
- 2. It is a bidentate ligand.
- 3. It is a chelating ligand.

### Summary of Correct Statements:
- The correct statements are 1, 2, and 3.