Different ionic compounds can release the same ions into solution. This ultimately means that different ionic compounds can affect the equilibrium of other ionic compounds.

Common ion effect: The solubility of a salt can be reduced by the presence of another salt that has a common ion.

Example: if NaCl is dissolved and HCl(aq) is added to the solution. This introduces chlorine ions and forces the equilibrium to the left due to Le Châtelier’s Principle, producing more NaCl(s).

Practice: If KBr is added to a solution containing PbBr2(aq), will more PbBr2 solidify? Yes

If KBr is added to a solution containing NaCl, will more NaCl precipitate? No, no common ion

Example: How many moles of PbCl2(s) will dissolve in 1L of 0.2M NaCl at SATP?

Common ion = Cl-1

[Cl-1]=[NaCl]=0.2M

Since there are no lead ions to start, Q=0 and the rxn shifts to the right

I     –           0          0.2

READ:
Sample Chemistry Unit Test

C    –         +x         +2x

E    –           x       0.2+2x

Cite this article as: William Anderson (Schoolworkhelper Editorial Team), "Common Ion Effect," in SchoolWorkHelper, 2019, https://schoolworkhelper.net/common-ion-effect/.

Help Us Fix his Smile with Your Old Essays, It Takes Seconds!

-We are looking for previous essays, labs and assignments that you aced!

-We will review and post them on our website.
-Ad revenue is used to support children in developing nations.
-We help pay for cleft palate repair surgeries through Operation Smile and Smile Train.

guest
0 Comments
Inline Feedbacks
View all comments