Question

Calculate the pH of a 2 M solution of H2SO4.

Answer 1

if we consider the first degree of dissociation

H₂SO₄ = H⁺ + HSO4^–

C(H⁺) = С(H₂SO₄) = 2 M

рН = – lg(C(H⁺)) = –lg 2 = -0.3

if we consider the second degree of dissociation

H₂SO₄ = 2H⁺ + SO₄^2-

2C(H⁺) = С(H₂SO₄) = 4 M

pH = – lg(2C(H⁺)) = -lg 4 = -0.6