Question

Identify oxidation number of Sulphur respectively in \(\text{SO}_2\) and \(\text{SO}_4^{2-}\) .

• A. \(+6,+4\)
• B. \(+4,+6\)
• C. \(+4,+3\)
• D. \(+3,+4\)

Hint:

Fix oxygen at -2 and make the sum equal the total charge.

Answer 1

The Correct Option is B

Step 1: Use charge balance:
In $\text{SO}_2$ the two oxygens contribute -4, so sulphur must be +4 to give a neutral molecule.

Step 2: Second species:
In the sulphate ion, four oxygens contribute -8 and the ion has a charge of -2. So sulphur supplies $-2 + 8 = +6$. The pair is +4 and +6, option (B).

Final Answer:
+4 and +6. \[ \boxed{+4,\ +6} \]