50 mL of 0.1M solution of a salt reacted with 25 mL of 0.1M solution of sodium sulphite. The half reaction for the oxidation of sulphite ion is,
SO₃²⁻(aq)+H₂O(ℓ)⟶SO₄²⁻(aq)+2H+(aq)+2e⁻.
If the oxidation number of metal in the salt was 3, what would be the new oxidation number of metal?
a. 0
b. 1
c. 4
d. 2
