How many of the following compounds violate octet rule
(i) `BrF_(5)` (ii) `SF_(6)` (iii) `IF_(7)` (iv) `XeOF_(4)`
(v) `CIF_(2)` (vi) `PCI_(4)^(o+)` .

Explanation

To determine how many of the given compounds violate the octet rule, we will analyze each compound one by one. The octet rule states that atoms tend to form bonds until they are surrounded by eight valence electrons.

### Step-by-Step Solution:

1. **BrF₅ (Bromine Pentafluoride)**:
- Bromine (Br) has 7 valence electrons.
- It forms bonds with 5 fluorine (F) atoms. Each F contributes 1 electron.
- Total electrons around Br = 7 (from Br) + 5 (from 5 F) = 12 electrons.
- **Conclusion**: BrF₅ violates the octet rule.

2. **SF₆ (Sulfur Hexafluoride)**:
- Sulfur (S) has 6 valence electrons.
- It forms bonds with 6 fluorine atoms.
- Total electrons around S = 6 (from S) + 6 (from 6 F) = 12 electrons.
- **Conclusion**: SF₆ violates the octet rule.

3. **IF₇ (Iodine Heptafluoride)**:
- Iodine (I) has 7 valence electrons.
- It forms bonds with 7 fluorine atoms.
- Total electrons around I = 7 (from I) + 7 (from 7 F) = 14 electrons.
- **Conclusion**: IF₇ violates the octet rule.

4. **XeOF₄ (Xenon Oxyfluoride)**:
- Xenon (Xe) has 8 valence electrons.
- It forms bonds with 4 fluorine atoms and 1 oxygen atom.
- Total electrons around Xe = 8 (from Xe) + 4 (from 4 F) + 2 (from O) = 14 electrons.
- **Conclusion**: XeOF₄ violates the octet rule.

5. **ClF₂ (Chlorine Difluoride)**:
- Chlorine (Cl) has 7 valence electrons.
- It forms bonds with 2 fluorine atoms.
- Total electrons around Cl = 7 (from Cl) + 2 (from 2 F) = 9 electrons.
- **Conclusion**: ClF₂ violates the octet rule.

6. **PCl₄⁺ (Phosphorus Tetrachloride cation)**:
- Phosphorus (P) has 5 valence electrons.
- Due to the +1 charge, it effectively has 4 valence electrons.
- It forms bonds with 4 chlorine atoms.
- Total electrons around P = 4 (from P) + 4 (from 4 Cl) = 8 electrons.
- **Conclusion**: PCl₄⁺ does not violate the octet rule.

### Summary of Results:
- Compounds that violate the octet rule: BrF₅, SF₆, IF₇, XeOF₄, ClF₂.
- Compound that does not violate the octet rule: PCl₄⁺.

### Final Count:
- **Total number of compounds that violate the octet rule**: 5