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.
Can We Write Your Essay?
Ace your next assignment with help from a professional writer. Free proofreading and copy-editing included.
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
Since there are no lead ions to start, Q=0 and the rxn shifts to the right
I – 0 0.2
C – +x +2x
E – x 0.2+2x
Can We Help with Your Assignment?
Let us do your homework! Expert writers in all subject areas are available and will meet your assignment deadline.