1 / 12

Chapter 21 Notes, part III

Chapter 21 Notes, part III. Ksp and Common Ion Effect. Solubility Product Constant. Salts have different solubilities; even salts we earlier considered insoluble have a very, very small amount of solubility in water.

hija
Download Presentation

Chapter 21 Notes, part III

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 21 Notes, part III Ksp and Common Ion Effect

  2. Solubility Product Constant • Salts have different solubilities; even salts we earlier considered insoluble have a very, very small amount of solubility in water. • The solubility product constant (Ksp) is an index of how soluble a salt is—the bigger the Ksp, the more soluble the salt is.

  3. Ksp • Ksp is based on Keq from Ch. 19; for example: • Keq for AgCl(s) D Ag+(aq) + Cl-(aq) would be: Keq = • But a solid is not dissolved, and thus does not have a constant, so: Ksp = [Ag+][Cl-] [Ag+][Cl-] [AgCl]

  4. Practice Problem #1 • What is the Ksp for Ag2SO4 if its solubility is 3.5x10-10M?

  5. Practice Problem #2 • What is the concentration of silver ions and chlorine ions in AgCl if Ksp=1.8x10-10 at 25oC?

  6. Practice Problem #3 • Calcium fluoride has Ksp=3.9x10-11. What is the concentration of fluoride ions?

  7. Practice Problem #4 • Ksp for Ag2S is 8x10-51. What is the concentration of Ag+ ions?

  8. Common Ion Effect • A common ion is an ion that two salts or a salt and an acid or base have in common. • The lowering of solubility of a substance by the addition of a common ion is called the common ion effect.

  9. Common Ion Effect • For example: • PbCrO4D Pb2+ + CrO42- Ksp=1.8x10-14 • If we add lead (II) nitrate (Pb(NO3)2), we are adding a common ion (see the dissociation reaction on the board).

  10. Common Ion Effect • Due to LeChatelier’s principle, the reaction will shift left because of the increased Pb2+ concentration, causing formation of PbCrO4 solid.

  11. Practice Problem #5 • Predict whether barium sulfate will precipitate if of 0.0010mol barium nitrate is mixed with 1.0L of 0.0040M sodium sulfate to form a 1.0L solution (Ksp of BaSO4 = 1.1x10-10)

  12. Practice Problem #6 • Predict whether silver cyanide will precipitate if 500mL of 0.00012M silver nitrate is mixed with 500mL of 0.00040M sodium cyanide to form a 1.0L solution (Ksp of AgCN=2.0x10-12)

More Related