Quiz 5 2015.01.07

1. HCl gas is in a 1.21-L cylinder at 0.870 atm and 28.0° C. This gas is dissolved in

750.0 mL of water. Calculate the pH of this solution (assume no volume change).

2. How much water should be added to 10.0 mL of 12.0 M HCl so that it has the same

pH as 0.90 M acetic acid (Ka = )? (Assume the volumes are additive.)

CH3COOH ↹ CH3COO- + H

+

反應前 0.9

反應後 0.9-x x x

3. Arrange the following 0.10 M solutions from lowest to highest pH: NaF, NaC2H3O2,

C5H5NHCl, KOH, HCN. (Ka for HCN is ; Ka for HF is ; Ka

for HC2H3O2 is ; and Kb for C5H5N is )

C5H5NHCl, HCN, NaF, NaC2H3O2, KOH

4. Calculate [H+] in a M solution of NH4Cl. (Kb for NH3 = )

NH4Cl ↹ NH3 + HCl (

)

反應前

反應後

5. Calculate the pH of a M solution of HCl.