AgNO3 (aq) + NaCl(aq)
AgCl(s) + NaNO3(aq)
What happens when you put
AgNO3 and NaCl in water?
AgNO3 (aq) + NaCl(aq)
AgCl(s) + NaNO3(aq)
What really happens when you put
AgNO3 and NaCl in water?
KEY POINT:
NaCl (aq)
really means:
Na +1 (aq)
“dissociated ions”
or
“ions in solution”
+
Cl -1 (aq)
What is Dissolving ?
When an ionic compound (eg salt) dissolves in
water, the compound disassociates. (breaks
apart into cations and anions)
Ex: Ca(NO3)2(s)
2O ( l )
H

Ca2+(aq) + 2NO3-(aq)
When a covalent compound (eg sugar) dissolves in
water, the molecules simply disperse; they do not
disassociate. Molecules of the covalent
compounds simply disperse due to attraction with
polar water molecules.
An Ionic
Compound
Dissolves:
A Covalent
Compound
Dissolves:
KEY POINT:
Mg(NO3)2 (aq)
really means:
Mg +2 (aq)
“dissociated ions”
or
“ions in solution”
+ 2(NO3) -1 (aq)
KEY POINT:
AgCl (s)
really means:
AgCl (s)
Solid Silver (I) Chloride.
AgNO3 (aq) + NaCl(aq)
AgCl(s) + NaNO3(aq)
What happens when you put
AgNO3 and NaCl in water?
AgNO3
NaCl
Ag+
NO3-
Na+
Cl-
Na+
NO3Ag+ Cl-
Na+
NO3AgCl
Na+
NO3-
AgCl
AgCl(s)
precipitate
NO
3
NO
+
+
3
NO3
Na Na
Na+
NO3-NO3- Na+
+
Na+
Na
NO
+
3
NO
Na
+
3
NO3
Na
Na+
AgCl(s)
AgNO3 (aq) + NaCl(aq)
AgCl(s) + NaNO3(aq)
complete ionic equation
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq)
AgCl (s) + NO3- (aq) + Na+ (aq)
NO3-
Na+
AgCl
Reaction
No Reaction
+
Na
NO3
AgCl
These ions do not participate
in the reaction. They are called
SPECTATOR IONS
NO3-
AgCl
Na+
The net ionic equation is constructed from the complete ionic equation:
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq)
AgCl (s) + NO3- (aq) + Na+ (aq)
NO3- and Na+ are not participating in the reaction
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq)
AgCl (s) + NO3- (aq) + Na+ (aq)
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq)
AgCl (s) + NO3- (aq) + Na+ (aq)
net ionic equation
Ag+ (aq) + Cl- (aq)
AgCl (s)
Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq)
AgCl (s) + NO3- (aq) + Na+ (aq)
net ionic equation
Ag+ (aq) + Cl- (aq)
AgCl (s)
– Complete molecular equation• describes double replacement reaction
– Complete ionic equation• more accurately shows the reacting species as ions
and the products either as ions or a precipitate
– Net ionic equation• focuses only on the ions REACTING
– Spectator ions are those ions that do NOT participate
in the reaction
PREDICTING THE FORMATION OF A
PRECIPITATE
• Consider the possibility that a precipitate may
form.
• Must use the solubility table on page 227 to
decide.
• Possible outcomes
– No visible reaction (nvr)
– Formation of one ppt.
– Formation of two ppt. (rare occurrence)
Basic Chemical equation
AgNO3(aq) + KCl(aq) AgCl(s) + KNO3(aq)
Complete ionic equation shows ions in solution
Ag+ (aq) + NO3(aq) + K+ (aq) + Cl-(aq)  AgCl(s)
+ K+ (aq) + NO3- (aq)
Net ionic equation shows ions in rxn
Ag+ (aq) + Cl-(aq)  AgCl(s)
link
(leave out spectator ions)