Ion Concentration

Disssociation:

-Ionic Particles are made up of 2 parst:

• Cation: + charged particles
• Anion: - charged particles

-When ionic compounds are dissolved in Water the cation and anion separate from each other
-This process is called dissociation.
-When writing dissociation equ'ns the atoms and charges must be ballanced
-The dissociation equ'n for NaCl is Na (+) + Cl (-)

EX// 

What are the following compound's Dissociation equ'ns?

-BaSO4 --> Ba (2+) + SO4 (2-)

-Al2(SO4)3 --> 2Al (3+) + 3SO4 (2-)

-If the volume doesn't change then the concentration of the individual ions depends on the balanced coefficients in the dissociation equ'n.

EX//

Determine the Ion Concentrations...

- 0.250 M of the sol'n KOH:

KOH --> K (+) + OH (-) 

0.250 mol/L x 1/1 + 0.250 M of [K+] 
*because there is a 1:1 ratio for this compound, [OH-] has the same ion concentration as [K+]. 

- A sol'n made from dissolving 2.5g of Ba3(PO4)2 in 50mL of water:

Ba3(PO4)2 --> 3Ba (2+) + 2PO4 (3+)

2.5g x 1 mol/601.9g= 0.00415mol / 0.050L = 0.831 mol/L x 3/1 = 0.249 M of [Ba 2+]
   "                     "                       "                           "              x 2/1 = 0.166 M of [PO4 3+]

A helpful video... :)