Consider the following statements.
I. The formula for the entire coordination entity, whether charged or not, is enclosed in square brackets.
II. Formulas of polyatomic ligands are enclosed in parentheses.
III. Ligand abbreviation are also enclosed in parentheses.
The correct statement (s) is /are

Options

A. I and II
B. II and III
C. I and III
D. All of these

Answer

To determine the correctness of the given statements regarding coordination compounds, let's analyze each statement step by step.

### Step 1: Analyze Statement I
**Statement I:** The formula for the entire coordination entity, whether charged or not, is enclosed in square brackets.

- **Explanation:** In coordination chemistry, the entire coordination complex is indeed represented within square brackets. This includes both charged and neutral complexes. For example, in the complex [Fe(CN)6]4-, the entire entity is enclosed in square brackets.

**Conclusion:** Statement I is **True**.

### Step 2: Analyze Statement II
**Statement II:** Formulas of polyatomic ligands are enclosed in parentheses.

- **Explanation:** Polyatomic ligands, which consist of multiple atoms, are typically represented within parentheses in coordination compounds. For example, in the complex [Co(NH3)6]3+, the ammonia (NH3) ligands are shown in parentheses to indicate that they are polyatomic ligands.

**Conclusion:** Statement II is **True**.

### Step 3: Analyze Statement III
**Statement III:** Ligand abbreviations are also enclosed in parentheses.

- **Explanation:** When using abbreviations for ligands, such as "en" for ethylenediamine or "NH3" for ammonia, these abbreviations are also enclosed in parentheses. This helps to clarify that they represent ligands in the coordination complex. For instance, in [Cu(en)2]2+, the abbreviation "en" is enclosed in parentheses.

**Conclusion:** Statement III is **True**.

### Final Conclusion
All three statements are correct:
- Statement I: True
- Statement II: True
- Statement III: True

Thus, the correct answer is that all statements are true.

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