Net Ionic Equations

Mr Nelson - 2010

Old School

• Write out the reaction for:

• Silver nitrate solution reacts in a double replacement reaction with potassium chloride solution to form silver chloride and potassium nitrate.

Ionic Equation• In the ionic equation all electrolytes (soluble ionic salts)

are dissociated into their ions.

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

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

Net Ionic Equation• To form the net ionic equation, cross out anything that

does not change from the left side of the equation to the right.

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

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

Net Ionic Equation• To form the net ionic equation, cross out anything that

does not change from the left side of the equation to the right.

• The only things left in the equation are those things that change (i.e., react) during the course of the reaction.

Ag+(aq) + Cl-(aq) AgCl (s)

Net Ionic Equation• The net ionic equation, is a simplified version of what

reacted!• The only things left in the equation are those things that

change (i.e., react) during the course of the reaction.• Those things that didn’t change are called spectator ions.

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

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

Writing Net Ionic Equations

1. Write a balanced chemical equation.

2. Write all soluble salts as ions.

3. Cross out anything that remains unchanged from the left side to the right side of the equation.

4. Write the net ionic equation with the species that remain.

Prelab for Lab 20

• Make Data Tables for Sets 1 – 3

• Predict Precipitates – make some kind of mark in the appropriate box to indicate where you would expect them to form.

For Lab 20• Title• For Set #1 REACTIONS:

– Write the reaction– Write complete Ionic Equation– Write the net ionic Equation

• For Sets 2 & 3, for REACTIONS ONLY– Write the reaction– Write the net ionic equation

• Conclusion – summary of ions/comp soluble vs in soluble

• Discussion – any ppts that formed that ‘should not have’