Skip to main content
Chemistry LibreTexts

The Common-Ion Effect

  1. Last updated
  2. Save as PDF
  • Page ID
    3068

    • Chemical Concept Demonstrated

    • Common-ion effect

    Demonstration

    AgNO3 and NaOAc are added to a beaker of water, and the solution is filtered.
    • The crystallizing dishes are half-filled with the filtrate.
    • AgNO3 is added to the first dish.
    • NaOAc is added to the second.
    		 common.gif

    Observations

    AgOAc precipitates in both dishes.

    Explanation (including important chemical equations)

    The common-ion effect is the decrease in the solubility of a salt that occurs when the salt is dissolved in a solution that contains another source of one of its ions. The filtrate is a saturated solution of Ag+ and OAc- ions. When either AgNO3 or NaOAc is added to the filtrate, the solubility of the ions in the saturated solution decreases, and the Ag + and OAc- ions crash out as AgOAc.

    AgNO3 (aq) + OAc - (aq) <=> AgOAc (s)

    NaOAc (aq) + Ag + (aq) <=> AgOAc (s)

    Contributors

    1. Back to top
    • Was this article helpful?

    Recommended articles

    1. Article type
      Section or Page
      Show Page TOC
      no on page
    2. Tags
      1. fundamental