CHM 2046C Module 11 Chapter 17 Sample Exam

Part I: pH Polyprotic acid 10 points

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

K_a1 = 1.2 x 10 ^-2 K_a2 = 6.2 x 10 ^-8

(a) Show both ionization reactions,

(b)write the equilibrium expressions for both)

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

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