What is molarity of H2SO4 having pH2?

Answer 1

Only the first ionization for H₂SO₄ contributes significantly to the hydrogen ion concentration, and the pH. Since the pH is given to only 1 significant figure (pH = 2), the concentration of acid to produce this will depend only on the first ionization.

H₂SO₄ ==> H⁺ + HSO₄^- Strong acid

HSO₄^- ==> H⁺ + SO₄^2- Ka = ~1.3x10^-2

Ignoring the second ionization, we have...

pH = 2

[H⁺] = 1x10^-2 M