Ion Concentration!

Dissociation!

Ionic compounds consist of two parts:

-Cation: a positively charged particle

-Anion: a negatively charged particle

When dissolved in water, ionic compounds separate into the Cation and Anion.

-This process is known as "Dissociation."

When writing dissociation equations the atoms and the charges must balance.

Example

Na3PO4(s)--> Fe 2+(aq) + Cl-(aq)

In some cases the volume doesn't change, in this case the concentration of the individual ions then depend on the balanced coefficients in the dissociation equation.

If [Cl-] = 0.365M in a solution of AgCl what is the solution's concentration?

AgCl--> Ag+ + Cl-

0.365 x 1/1= 0.365M

A 250ml solution of 0.760M Pbcl2 is added to 340ml solution of 0.178M NaOH. Determine the final [Cl-].

Pbcl2 + NaOh--> Pb2+ + 2Cl- + Na+ + OH-

0.760 x 0.250 ml= 0.19 mol of PbCl2

0.19 mol x 2/1= 0.38

0.38/0.590= 0.64M