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) + Cl -1 (aq)

“dissociated ions”or “ions in solution”

KEY POINT:

AgNO3 (aq)

really means:

Ag +1 (aq) + NO3 -1 (aq)

“dissociated ions”or “ions in solution”

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) Ca2+(aq) + 2NO3-

(aq)

)(2 lOH

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:

AgCl (s)

really means:

AgCl (s)

Solid Silver (I) Chloride.

KEY POINT:

NaNO3 (aq)

really means:

Na +1 (aq) + NO3 -1 (aq)

“dissociated ions”or “ions in solution”

AgNO3 (aq) + NaCl(aq) AgCl(s) + NaNO3(aq)

What happens

when you put

AgNO3 and NaCl

in water?

AgNO3 NaCl

Ag+

NO3-

Na+

Cl-

Ag+

NO3-

Na+

Cl-

AgCl

NO3-

Na+

AgCl

NO3-

Na+

AgCl(s)precipitate

NO3-

Na+

NO3-Na+

NO3-

Na+NO3-Na+Na+ NO3

-

Na+

NO3- Na+

NO3-

Na+

NO3-

Na+

AgCl(s)

Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq)

AgCl (s) + NO3- (aq) + Na+ (aq)

AgNO3 (aq) + NaCl(aq) AgCl(s) + NaNO3(aq)

complete ionic equation

NO3- Na+

AgCl

Reaction

AgCl

NO3-Na+

No Reaction

AgCl

NO3- Na+

These ions do not participatein the reaction. They are called

SPECTATOR IONS

Ag+ (aq) + NO3- (aq) + Na+ (aq) + Cl- (aq)

AgCl (s) + NO3- (aq) + Na+ (aq)

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)

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 rules 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)

(leave out spectator ions)