Which of the following has//have been arranged in order of decreasing oxidation number of sulphur?

Options

A. `H_(2)S_(2)O_(7) gt Na_(2)S_(4)O_(6) gt Na_(2)S_(2)O_(3) gt S_(8)`
B. `SO^(2+) gt SO_(4)^(2-) gt SO_(3)^(2-) gt HSO_(4)^(ө)`
C. `H_(2)SO_(5) gt H_(2)SO_(3) gt SCl_(2) gt H_(2)S`
D. `H_(2)SO_(4) gt SO_(2) gt H_(2)S gt H_(2)S_(2)O_(8)`

Explanation

To determine which of the given compounds has been arranged in order of decreasing oxidation number of sulfur, we need to calculate the oxidation state of sulfur in each compound provided in the options. Let's go through the calculations step by step.

### Step 1: Identify the Compounds
Assuming the compounds are:
1. H2S2O7
2. Na2S4O6
3. Na2S2O3
4. H2S2O8

### Step 2: Calculate the Oxidation State of Sulfur in Each Compound

#### For H2S2O7:
1. Let the oxidation state of sulfur be \( x \).
2. The oxidation state of hydrogen is \( +1 \) and oxygen is \( -2 \).
3. The equation based on the compound is:
\[ 2(+1) + 2x + 7(-2) = 0 \]
Simplifying:
\[ 2 + 2x - 14 = 0 \implies 2x - 12 = 0 \implies 2x = 12 \implies x = +6 \]
**Oxidation state of sulfur = +6**

#### For Na2S4O6:
1. Let the oxidation state of sulfur be \( x \).
2. The oxidation state of sodium is \( +1 \) and oxygen is \( -2 \).
3. The equation is:
\[ 2(+1) + 4x + 6(-2) = 0 \]
Simplifying:
\[ 2 + 4x - 12 = 0 \implies 4x - 10 = 0 \implies 4x = 10 \implies x = +2.5 \]
**Oxidation state of sulfur = +2.5**

#### For Na2S2O3:
1. Let the oxidation state of sulfur be \( x \).
2. The equation is:
\[ 2(+1) + 2x + 3(-2) = 0 \]
Simplifying:
\[ 2 + 2x - 6 = 0 \implies 2x - 4 = 0 \implies 2x = 4 \implies x = +2 \]
**Oxidation state of sulfur = +2**

#### For H2S2O8:
1. Let the oxidation state of sulfur be \( x \).
2. The equation is:
\[ 2(+1) + 2x + 8(-2) = 0 \]
Simplifying:
\[ 2 + 2x - 16 = 0 \implies 2x - 14 = 0 \implies 2x = 14 \implies x = +7 \]
**Oxidation state of sulfur = +7** (Note: This is not possible for sulfur, as the maximum oxidation state is +6. Thus, sulfur here is effectively +6 due to structural reasons.)

### Step 3: Summarize the Oxidation States
- H2S2O7: +6
- Na2S4O6: +2.5
- Na2S2O3: +2
- H2S2O8: +6 (but structurally behaves as +6)

### Step 4: Arrange in Decreasing Order
The decreasing order of oxidation states of sulfur is:
1. H2S2O7: +6
2. H2S2O8: +6
3. Na2S4O6: +2.5
4. Na2S2O3: +2

### Conclusion
The correct options that show decreasing oxidation number of sulfur are:
- H2S2O7
- H2S2O8