Electrolyte:
A substance which dissolve to give an electrically conducting solution containing ions.
Example: HCl (g) à H+ (aq)
+ Cl- (aq)
Non electrolyte:
A non electrolyte is a substance which dissolve to give a non conducting solution containing only neutral molecules
Example: Br2(l) à
Br2(aq)
Classifying Compounds as ionic or molecular:
Ionic compounds:
compound made up of a metal and a non metal is usually ionic in solution.
Example: FeCl3(s) à Fe3+(aq)
+ 3Cl- (aq)
Molecular compound:
Compound made up of non metal and non metal generally forms molecular solutions.
Saturated solution:
If dissolved substance is in equilibrium with some undissolved substance.
Example: NaCl dissolced in water and some solid is sitting at the bottom of container.
Solubility: Equilibrium [substance] in solutions at given temperature.
Example: KCl (s) ßàK+(aq) +
Cl-(aq)
Saturation: Exist when some undissolved material is present and equilibrium exists between the dissolved
and the undissolved.
Example: KCl (s) ßàK+(aq) +
Cl-(aq)
Low Solubility: A substance is said to be at low solubility if a saturated solution of the substance
is less than 0.1 M.
Example: Equal volume of 0.2M compound and 0.2 compound B are mixed. After dillution both compound A
and B are pressent as 0.1 M solution. If precipitate forms when compound A and B are mixed together, it qualifies as having
low solubility.
Note: When two ions form a compound having low solubility the mixing of two ions will cause a precipitate
to form.
Alkali ions, H+, NH4+ or NO3-
don't precipitate.
If needed particular anion in solution alkali ions should be used to combine with anion.
Example: 2Ag+(aq) + CO32-(aq)
ßàAg2CO3(s)
Qualitative analysis: Involves the use of experimental procedures
to determine which elements or ions are present.
Example: Ag+
and Sr2+ one or both cations are present
