Question

4. You decide to try to separate 0.100 M Hg22+ (pKsp = 17.91) from 0.0750 M Ag+ (pKsp = 9.74) from each other in a 50.00 mL sample by precipitation as chloride salts with 0.0500 M HCl. Show which ion will precipitate first?

5. a. What is the pH of a solution of 0.0100 M HCl?

b. What is the pH of a solution of 0.0100 M HCl dissolved in 0.01334 M potassium carbonate when taking solution activity into account?

*please complete by 7:00 am 2/24/16 all qustions (show all work and steps)!!!!

Answer 1

4.

PKSp = 17.91

-logKsp = 17.91

KSp = 10^-17.91 = 1.23*10^-18

PKsp = 9.74

-logKsp = 9.74

KSp = 10^-9.74 = 1.81*10^-10

KSp = [Hg₂+2] [Cl-]

1.23*10^-18 = 0.01*[Cl-]

[Cl-]    = 1.23*10^-16 M

KSp = [Ag+][Cl-]

1.81*10^-10 = 0.075[Cl-]

[Cl-] = 2.4*10^-9 M

Hg_2⁺²ion form firat pricipitate

5. HCl is strong acid

HCl    ----> H⁺ + Cl^-

0.01M        0.01M

[HCl] = [H+]

[H+] = 0.01M

PH   = -log[H+]

     = -log10^-2

   = 2log10

= 2