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Ionic Equations Honors chemistry – Semester 1
Total Ionic Equations
Shows all the ions, compounds and states of matter for compounds in a reaction
• Aqueous (dissolved in water) - (aq)
• Solid - (s)
• Gas - (g)
• Liquid - (l)
Soluble ionic compounds are split and written as cations and anions
• Shows charges on all ions
Total Ionic Equations
Which ionic compounds are soluble??
Soluble Insoluble All compounds with Group 1 (Alkali metals) as well as NH4
+
All carbonates, except those with Group 1 and NH4
+
All phosphates, except those with Group 1 and NH4
+
All nitrates
All halogens (Group 7A), except with Ag+ and Pb2+
All sulfates, except those with Ca2+, Sr2+, Ba2+, Hg2+, Pb2+
Total Ionic Equations
Ionic compounds in water:
• NaCl is soluble
Na+(aq) + Cl-
(aq)
• BaSO4 is insoluble
BaSO4(s)
Na+(aq)
Na+(aq) Na+
(aq)
Na+(aq)
Na+(aq)
Na+(aq)
Cl-(aq)
Cl-(aq)
Cl-(aq) Cl-
(aq)
Cl-(aq)
Cl-(aq)
BaSO4(s) BaSO4(s) BaSO4(s) BaSO4(s)
Examples
Which ionic compounds are soluble??
Na2SO4
CaSO4
Hg(NO3)2
CaCO3
Rb2CO3
MgF2
Soluble Insoluble All compounds with Group 1 (Alkali metals) as well as NH4
+
All carbonates, except with Group 1 and NH4
+
All nitrates All phosphates, except with Group 1 and NH4
+
All halides (Group 7A), except Ag+ and Pb2+
All sulfates, except those with Ca2+, Sr2+, Ba2+, Hg2+, Pb2+
Y
N
Y
N
Y
Y
Practice
Write the formulas of two soluble and two insoluble ionic compounds
Soluble Insoluble All compounds with Group 1 (Alkali metals) as well as NH4
+
All carbonates, except those with Group 1 and NH4
+
All nitrates
All halides (Group 7A), except Ag+ and Pb2+
All sulfates, except those with Ca2+, Sr2+, Ba2+, Hg2+, Pb2+
Writing Total Ionic Equations
Write the word equation if required
Write the unbalanced equation
Balance the equation
Split soluble ions, annotate states of matter and charges for all ions and compounds
Writing Total Ionic Equations
Potassium iodide and lead (II) nitrate, when dissolved in water, become lead (II) iodide and potassium nitrate
• KI + Pb(NO3)2 → PbI2 + KNO3 (unbalanced)
• 2KI + Pb(NO3)2 → PbI2 + 2KNO3 (balanced)
• 2K+ (aq) + 2I-(aq) + Pb2+
(aq) + 2NO3-(aq) →
PbI2(s) + 2K+ (aq) + 2NO3
-(aq)
Practice
Write a total ionic equation for:
AgNO3(aq) + KBr(aq) → AgBr(s) + KNO3(aq)
Ag+(aq) + NO3
-(aq) + K+
(aq) + Br-(aq) → AgBr(s) + K+
(aq) + NO3-(aq)
Ni(s) + Pb(NO3)2(aq) → Ni(NO3)2(aq) + Pb(s)
Ni(s) + Pb2+(aq) + 2NO3
-(aq) → Ni2+
(aq) + 2NO3-(aq) + Pb(s)
Ca(s) + 2H2O(l) → Ca(OH)2(aq) + H2(g)
Ca(s) + 2H2O(l) → Ca2+(aq) + 2OH-
(aq) + H2(g)
• Pause
Spectator Ions
Spectator ions remain unchanged in solution as aqueous ions
Spectator ions appear as both reactants and products in the equation
• 2K+ (aq) + 2I-(aq) + Pb2+
(aq) + 2NO3-(aq) →
PbI2(s) + 2K+ (aq) + 2NO3
-(aq)
Net Ionic Equations
Net Ionic Equation
= Total Ionic Equation – spectator ions
• 2K+ (aq) + 2I-(aq) + Pb2+
(aq) + 2NO3-(aq) →
PbI2(s) + 2K+ (aq) + 2NO3
-(aq)
• Net Ionic Equation
• 2I-(aq) + Pb2+
(aq) → PbI2(s)
Example
Balanced equation
Zn + CuSO4 → Cu + ZnSO4
Total ionic equation
Zn(s) + Cu2+(aq) + SO4
2-(aq) → Cu(s) + Zn2+
(aq) + SO42-
(aq)
Identify and remove spectator ions to leave net ionic equation
Zn(s) + Cu2+(aq) → Cu(s) + Zn2+
(aq)
Example
Balanced equation
K2SO4(aq) + Ba(NO3)2(aq) → 2KNO3(aq) + BaSO4(s)
Total ionic equation
2K+(aq) + SO4
2-(aq) + Ba2+
(aq) + 2NO3-(aq) →
2K+(aq) + 2NO3
-(aq) + BaSO4(s)
Identify and remove spectator ions to leave net ionic equation
SO42-
(aq) + Ba2+(aq) → BaSO4(s)
Practice
Using your earlier work, write a net ionic equation for:
AgNO3(aq) + KBr(aq) → AgBr(s) + KNO3(aq)
Ag+(aq) + NO3
-(aq) + K+
(aq) + Br-(aq) → AgBr(s) + K+
(aq) + NO3-(aq)
Ni(s) + Pb(NO3)2(aq) → Ni(NO3)2(aq) + Pb(s)
Ni(s) + Pb2+(aq) + 2NO3
-(aq) → Ni2+
(aq) + 2NO3-(aq) + Pb(s)
Ca(s) + H2O(l) → Ca(OH)2(aq) + H2(g)
Ca(s) + 2H2O(l) → Ca2+(aq) + 2OH-
(aq) + H2(g) No spectator ions!