What is the oxidation number of selenium in H₂SeO₃?
Let Se = x. H = +1, O = -2. Equation: 2(+1) + x + 3(-2) = 0, 2 + x - 6 = 0, x = +4.
Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Classical and Electronic Concept of Redox and Oxidation Number