CHEM 1212 Module Eleven-Chapter 17 Name:____________

Part I: pH polyprotic acid Problem 10 points

Sufurous acid, H₂SO₃, is a weak acid capable of providing two hydrogen ions.

(a) What is the pH of a 0.45 M solution of H₂SO₃

(Show both ionization reactions, write the equilibrium expressions for both)

Ka₁ = 1.2 x 10 ^-2 Ka₂ = 6.2 x 10 ^-8

(b) What is the equilibrium concentration of the sulfite ion, SO₃ ^2- in the 0.45 M solution of H₂SO₃ ?