Calculate the oxidation number of sulfur in the following molecules and ions:
`(i) H_(2)SO_(4) , (ii) Na_(2)SO_(4), (iii) SO_(4)^(2-), (iv)S_(2)O_(4)^(2-)`

Explanation

To calculate the oxidation number of sulfur in the given molecules and ions, we will follow a systematic approach for each compound.

### (i) For H₂SO₄:

1. **Assign oxidation states**:
- Let the oxidation number of sulfur (S) be \( x \).
- Hydrogen (H) has an oxidation number of +1. Since there are 2 hydrogen atoms, their total contribution is \( +2 \).
- Oxygen (O) has an oxidation number of -2. There are 4 oxygen atoms, so their total contribution is \( -8 \).
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