November 25, 2024, 07:23:45 AM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: Solubility + Common Ion Effect  (Read 3865 times)

0 Members and 2 Guests are viewing this topic.

Offline student8607

  • Full Member
  • ****
  • Posts: 227
  • Mole Snacks: +2/-3
Solubility + Common Ion Effect
« on: March 17, 2009, 12:17:20 PM »
Calculate the molar solubility of MgF2 in 0.1M MgCl2 at 25 degrees Celsius

The Ksp = 7.4x10-11

7.4x10-11 = (0.1)(2x)2
4x2 = 0.1/7.4x10-11
divide by 4
take the square root
x = 18380

but I don't believe that is right?
Logged

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27862
  • Mole Snacks: +1813/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Solubility + Common Ion Effect
« Reply #1 on: March 17, 2009, 12:18:39 PM »
Quote from: student8607 on March 17, 2009, 12:17:20 PM
7.4x10-11 = (0.1)(2x)2
4x2 = 0.1/7.4x10-11

Chek your math.
Logged
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline student8607

  • Full Member
  • ****
  • Posts: 227
  • Mole Snacks: +2/-3
Re: Solubility + Common Ion Effect
« Reply #2 on: March 17, 2009, 12:21:18 PM »
Ohhh now I see.
Logged

Offline student8607

  • Full Member
  • ****
  • Posts: 227
  • Mole Snacks: +2/-3
Re: Solubility + Common Ion Effect
« Reply #3 on: March 17, 2009, 12:22:33 PM »
7.4x10-11 = (0.1)(2x)2
7.4x10-11 / 0.1 = (2x)2


Now I get 1.36 x 10-5 . thanks
Logged

Offline student8607

  • Full Member
  • ****
  • Posts: 227
  • Mole Snacks: +2/-3
Re: Solubility + Common Ion Effect
« Reply #4 on: March 17, 2009, 01:30:10 PM »
ANOTHER question:

A particular saturated solution of PbI2 has a Ksp of 8.45 x 10-9
If [Pb2+] = 2.5x10-4 what is [I-]

8.45x10-9 = [(2x)2] [2.5x10-4]
3.38x10-5 = 2x2
divide by 4
take square root
got 0.00291?
Logged
Pages: [1]   Go Up
« previous next »
Sponsored Links