Question 1
Assuming no volume change on mixing, what mass of ammonium chloride should be added to 250.0 mL of 0.25 M aqueous ammonia to produce a solution of pH 10.70? (
Kb for ammonia is 1.8 × 10
-5)
◦ 3.7 mg
◦ 120 mg
◦ 40 mg
◦ 30 mg
◦ 80 mg
Question 2
Calculate the percent ionization of nitrous acid in an aqueous solution that is 0.266 mol L
-1 in nitrous acid
and 0.112 mol L
-1 in potassium nitrite (KNO
2). The acid dissociation constant of nitrous acid is
◦ 29.6
◦ 0.402
◦ 11.2
◦ 1.34 × 10
-3◦ 1.55