How many of the following compounds have `(p pi-dpi)` multiple bonds
(i) `SO_(2)` (ii) `SO_(3)` (iii) `H SO_(4)^(Theta)` (iv) `SO_(4)^(2-)`
(v) `SO_(3)^(3-)` (vi) `H SO_(3)^(Theta)` .

Explanation

To determine how many of the given compounds have `(p pi-d pi)` multiple bonds, we need to analyze each compound one by one.

### Step-by-Step Solution:

1. **Identify the Compounds**: We have the following compounds to analyze:
- (i) `SO2`
- (ii) `SO3`
- (iii) `HSO4^-`
- (iv) `SO4^(2-)`
- (v) `SO3^(3-)`
- (vi) `HSO3^-`

2. **Analyze `SO2`**:
- In `SO2`, sulfur forms two double bonds with oxygen. The bond type here includes a `p pi-d pi` bond because sulfur has available d orbitals and can overlap with the p orbitals of oxygen.
- **Conclusion**: `SO2` has `p pi-d pi` bonds.

3. **Analyze `SO3`**:
- In `SO3`, sulfur forms three double bonds with oxygen. This involves two `p pi-d pi` bonds and one `p pi-p pi` bond.
- **Conclusion**: `SO3` has `p pi-d pi` bonds.

4. **Analyze `HSO4^-`**:
- In `HSO4^-`, the sulfur is bonded to four oxygen atoms, with one of them being a double bond. The structure can be considered similar to `SO4^(2-)` where the sulfur is surrounded by four oxygen atoms.
- **Conclusion**: `HSO4^-` has `p pi-d pi` bonds.

5. **Analyze `SO4^(2-)`**:
- In `SO4^(2-)`, sulfur forms four bonds with oxygen, with two of them being double bonds. This structure also allows for `p pi-d pi` bonding.
- **Conclusion**: `SO4^(2-)` has `p pi-d pi` bonds.

6. **Analyze `SO3^(3-)`**:
- In `SO3^(3-)`, sulfur forms three bonds with oxygen, but the bonding does not involve `p pi-d pi` interactions; it primarily involves `p pi-p pi` bonds.
- **Conclusion**: `SO3^(3-)` does not have `p pi-d pi` bonds.

7. **Analyze `HSO3^-`**:
- In `HSO3^-`, sulfur forms three bonds with oxygen, but similar to `SO3^(3-)`, these are primarily `p pi-p pi` bonds.
- **Conclusion**: `HSO3^-` does not have `p pi-d pi` bonds.

### Final Count:
- The compounds that have `p pi-d pi` multiple bonds are: `SO2`, `SO3`, `HSO4^-`, and `SO4^(2-)`.
- Therefore, **4 compounds** have `p pi-d pi` multiple bonds.

### Summary of Results:
- (i) `SO2` - Yes
- (ii) `SO3` - Yes
- (iii) `HSO4^-` - Yes
- (iv) `SO4^(2-)` - Yes
- (v) `SO3^(3-)` - No
- (vi) `HSO3^-` - No

### Total Compounds with `p pi-d pi`: **4**