Which one of the following statement(s) is/are false?

Options

A. weak ligands like `F^(-),Cl^(-) and and OH^(-)` usually form low spin complexes
B. Strong ligand like `CN^(-)` and `NO_(2)^(-)`, generally form high spin complexes
C. `[FeF_(6)]^(3-)` is high spin complex
D. `[Ni(CO)_(4)]` is high spin complex

Explanation

To determine which statements are false regarding coordination compounds, we will analyze the properties of ligands and their influence on the spin states of the complexes they form.

### Step-by-Step Solution:

1. **Understanding Ligands**:
- Ligands can be classified as weak field ligands or strong field ligands based on their ability to cause electron pairing in the d-orbitals of the metal ion.
- Weak field ligands (e.g., F⁻, Cl⁻, OH⁻) tend to form high spin complexes because they do not cause significant pairing of electrons.
- Strong field ligands (e.g., CN⁻, NO₂⁻) typically form low spin complexes as they promote electron pairing.

**Hint**: Remember the classification of ligands based on their field strength and the resulting spin states of the complexes.

2. **Analyzing the Statements**:
- **Statement 1**: Weak spin ligands like fluorine, chlorine, and OH⁻ usually form low spin complexes.
- This statement is **false** because weak field ligands form high spin complexes.

- **Statement 2**: Strong ligands like cyanide (CN⁻) and NO₂⁻ generally form high spin complexes.
- This statement is also **false** because strong field ligands form low spin complexes due to electron pairing.

3. **Example of FeF₆³⁻**:
- For FeF₆³⁻, we calculate the oxidation state of Fe:
- F has a charge of -1, and there are 6 fluorine atoms: -6.
- Therefore, Fe must be +3 to balance the charge: Fe³⁺.
- The electronic configuration of Fe (atomic number 26) is [Ar] 3d⁶ 4s². For Fe³⁺, it becomes 3d⁵.
- With F⁻ being a weak field ligand, it does not cause pairing, resulting in a high spin configuration.

**Hint**: Remember to calculate oxidation states and electronic configurations to understand the spin states of the complexes.

4. **Example of Ni(CO)₄**:
- For Ni(CO)₄, the oxidation state of Ni is 0 since CO is a neutral ligand.
- The electronic configuration of Ni (atomic number 28) is [Ar] 3d⁸ 4s².
- CO is a strong field ligand, causing pairing of electrons, leading to a low spin configuration.

**Hint**: Strong field ligands lead to electron pairing, which is crucial in determining the spin state of the complex.

5. **Conclusion**:
- Both statements regarding weak field ligands forming low spin complexes and strong field ligands forming high spin complexes are false.
- Therefore, the correct answer is that both statements are false.

### Final Answer:
Both statements are false.