Question

1. Which of the following acids can be oxidized to form a stronger acid?
   1. H₃PO₄
   2. HNO₃
   3. H₂CO₃
   4. H₃BO₃
   5. H₂SO₃

_{The answer is e, But why? can someone provide a detailed explanation to why HSO3- is somehow stronger than H2SO3? dont all polyprotic acid become weaker once it dissociates? (ka1 >ka2)??}

Answer 1

This is a tricky question because all other than (e) are in maximum oxidised form as per addition of oxygen.

But in oxidation of H2SO3 it gives H2SO4.

as we know H2SO4 is stronger acid than H2SO3 as it contains more oxygen atoms which causes stability of its acidity.

In all other cases it gives next step of their acid

As H3PO4 gives H2PO4 ^- .

Which causes formation of weaker acid than previous one.

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