Given that the oxidation number of sulphur is -2, the equivalent weight of sulphur is

Options

A. 16
B. 32
C. 9
D. 4

Answer

To determine the equivalent weight of sulfur when its oxidation number is -2, we can follow these steps:

### Step 1: Understand the Concept of Equivalent Weight
The equivalent weight of a substance is defined as the mass of the substance that would combine with or displace one mole of hydrogen or half a mole of oxygen in a reaction. It can also be calculated using the formula:

\[ \text{Equivalent Weight} = \frac{\text{Molecular Weight}}{n \text{ factor}} \]

### Step 2: Determine the Molecular Weight of Sulfur
The molecular weight of sulfur (S) is approximately 32 g/mol.

### Step 3: Identify the n Factor
The n factor is related to the change in oxidation state of the element. In this case, since the oxidation number of sulfur is -2, we can consider that sulfur is gaining 2 electrons to reach this oxidation state from its elemental form (where the oxidation state is 0). Thus, the n factor for sulfur in this context is 2.

### Step 4: Calculate the Equivalent Weight
Using the formula for equivalent weight, we can substitute the values we have:

\[ \text{Equivalent Weight} = \frac{\text{Molecular Weight}}{n \text{ factor}} = \frac{32 \text{ g/mol}}{2} = 16 \text{ g/equiv} \]

### Conclusion
The equivalent weight of sulfur when its oxidation number is -2 is 16 g/equiv.

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