In which of the following compound, oxidation state of `'S'` is other than the `+6`

Options

A. peroxomonosulphuric acid (Caro's acid)
B. peroxodisulphuric acid ( Marshall's acid)
C. pyrosulphuric acid (oleum)
D. sodium thiosulphate (hypo)

Explanation

To determine in which of the given compounds the oxidation state of sulfur (S) is other than +6, we will analyze the oxidation states of sulfur in each compound provided.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given are:
- A) Karose acid (H2SO5)
- B) Marshall's acid (H2S2O8)
- C) Oleum (H2S2O7)
- D) Sodium thiosulfate (Na2S2O3)

2. **Calculate Oxidation State of Sulfur in Each Compound**:
- **A) Karose acid (H2SO5)**:
- The formula is H2SO5.
- Hydrogen (H) has an oxidation state of +1 (2 H = +2).
- Oxygen (O) has an oxidation state of -2 (5 O = -10).
- Let the oxidation state of sulfur be x.
- The equation becomes:
\[ 2 + x - 10 = 0 \implies x = +8 \]
- Thus, the oxidation state of sulfur in Karose acid is +6.

- **B) Marshall's acid (H2S2O8)**:
- The formula is H2S2O8.
- 2 H = +2, 8 O = -16.
- Let the oxidation state of sulfur be x.
- The equation becomes:
\[ 2 + 2x - 16 = 0 \implies 2x = 14 \implies x = +7 \]
- Thus, the oxidation state of sulfur in Marshall's acid is +6.

- **C) Oleum (H2S2O7)**:
- The formula is H2S2O7.
- 2 H = +2, 7 O = -14.
- Let the oxidation state of sulfur be x.
- The equation becomes:
\[ 2 + 2x - 14 = 0 \implies 2x = 12 \implies x = +6 \]
- Thus, the oxidation state of sulfur in Oleum is +6.

- **D) Sodium thiosulfate (Na2S2O3)**:
- The formula is Na2S2O3.
- 2 Na = +2, 3 O = -6.
- Let the oxidation state of sulfur be x for one sulfur and y for the other sulfur.
- The equation becomes:
\[ 2 + x + y - 6 = 0 \]
- In sodium thiosulfate, one sulfur is in the +6 oxidation state and the other is in the -2 oxidation state.
- Therefore, we can assign:
\[ x = +6 \text{ and } y = -2 \]

3. **Conclusion**:
- In sodium thiosulfate (Na2S2O3), one sulfur has an oxidation state of +6 and the other has -2. Therefore, the oxidation state of sulfur in sodium thiosulfate is other than +6.

### Final Answer:
The compound in which the oxidation state of sulfur is other than +6 is **D) Sodium thiosulfate (Na2S2O3)**.