The pH of 10⁻³ mol dm⁻³ of an aqueous solution of H₂SO₄ is: (Sindh MDCAT 2019)

For 10⁻³ M H₂SO₄, the first ionization is complete and the second contributes additional H⁺, giving [H⁺] greater than 10⁻³ M and pH close to 2.7.