Posted: February 10th, 2017

Sulfurous acid (H2SO3) has pKa1 = 1.91 and pKa2 = 7.18. At what pH does [HSO3-] = [SO32-]?

Part I Multiple Choice Questions (2 points each)

1.- Which of the following pairs of compounds and ions could be used to form a buffer solution? (a) 0.10 M HCl and 0.10 M NaCl (b) 0.10 M NH4Cl and 0.10 M NH3 (c) 0.10 M HNO2 and 1.0 x 10-4 M NaNO2

2.- Sulfurous acid (H2SO3) has pKa1 = 1.91 and pKa2 = 7.18. At what pH does [HSO3-] = [SO32-]? (a) 1.91 (b) 4.54 (c) 7.18

3.- In the following reaction, identify the conjugate acid and conjugate base: NO2- + H2O ↔ HNO2 + OH-. (a) HNO2, OH- (b) NO2-, H2O (c) NO2-, HNO2

4.- The predominant for dissolved CO2 in water at pH 13.25 is: (a) CO2 (b) H2CO3 (c) HCO3- (d) CO32-

5.- 4. Sulfurous acid (H2SO3) has pKa1 = 1.91 and pKa2 = 7.18. At what pH does [HSO3-] = [SO32-]?

(a) 1.91 (b) 4.54 (c) 7.18

6.- Calculate the hydrogen ion concentration of a 0.100 molar solution of chloroacetic acid. Ka for chloroacetic acid = 1.36 x 10-3. (a) 0.0117 molar (b) 0.0369 molar (c) 7.39 x 10-12 molar

7.- Which is the strongest base? (a) HCl (b) CH3NH2 (c) RbOH

8.- The equivalence point of a titration is defined as (a) the point of the titration where the indicator changes. (b) the actual measured volume of titrant required to complete a titration. (c) the volume associated with actual stoichiometric quantity of titrant required to complete a titration.