The oxidation state of S-atoms in Caro's and Marshall's acids are:

Options

A. `+6,+6`
B. `+6,+4`
C. `+6,-6`
D. `+4,+6`

Answer

To determine the oxidation states of sulfur in Caro's acid and Marshall's acid, we can follow these steps:

### Step 1: Understand the Structures of Caro's and Marshall's Acids
- **Caro's Acid** (Peroxymonosulfuric acid) has the formula H₂SO₅. It contains a sulfur atom bonded to two hydroxyl groups (–OH) and a peroxy linkage (–O–O–).
- **Marshall's Acid** (Peroxydisulfuric acid) has the formula H₂S₂O₈. It contains two sulfur atoms and peroxy linkages.

### Step 2: Assign Oxidation States
- **For Caro's Acid (H₂SO₅)**:
- The sulfur atom is bonded to four oxygen atoms (two through double bonds and two through single bonds).
- Assign oxidation states:
- Each oxygen in a double bond contributes -2 (2 × -2 = -4).
- Each oxygen in a single bond contributes -1 (2 × -1 = -2).
- The total contribution from oxygen = -4 + -2 = -6.
- The overall charge of the molecule is neutral (0), and there are two hydrogen atoms contributing +2.
- Therefore, the oxidation state of sulfur (S) can be calculated as follows:
\[ x + (-6) + 2 = 0 \implies x - 4 = 0 \implies x = +6 \]
- Thus, the oxidation state of sulfur in Caro's acid is **+6**.

- **For Marshall's Acid (H₂S₂O₈)**:
- There are two sulfur atoms, and the structure involves peroxy linkages.
- Each sulfur atom is similarly bonded to oxygen atoms.
- The same method applies:
- Each sulfur atom is bonded to four oxygen atoms (two double bonds and two single bonds).
- The contribution from oxygen is the same as above: -6.
- The overall charge of the molecule is neutral (0), and there are two hydrogen atoms contributing +2.
- Therefore, the oxidation state of each sulfur (S) can be calculated as follows:
\[ 2x + (-6) + 2 = 0 \implies 2x - 4 = 0 \implies 2x = 4 \implies x = +6 \]
- Thus, the oxidation state of sulfur in Marshall's acid is also **+6**.

### Final Answer:
- The oxidation state of sulfur in both Caro's acid and Marshall's acid is **+6**.

---