Ionic and Net Ionic Equations Vocabulary: -ionic equation -spectator ion -net ionic equation Ionic and Net Ionic Equations

REview AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(s) Write the balanced equation for the reaction between aqueous silver nitrate and aqueous sodium chloride. Be sure to indicate the states of all substances in your equation. AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(s)

REview AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(s) 1) When we say that AgNO3, Na2SO4, and NaNO3 are aqueous, what does that physically mean? 2) When we say that AgCl is a solid, what does that physically mean? AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(s)

REview AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(s) 1) Aqueous means that the ions are dissociated in the solution. Remember, dissociated means that the ions are not attracted to each other any more but are instead independent of each other in the solution and free to move. 2) Solid means that the ions are attracted to each other and not free to move within the solution. AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(s)

→ Review Reactants Products Ag+ (aq) Na+ (aq) Na+ (aq) NO3- (aq) All aqueous ions are free to move in solution. → Solid ions are attracted to each other and not free to move. This is the precipitate. Ag+ (aq) Na+ (aq) Na+ (aq) NO3- (aq) Cl- (aq) NO3- (aq) AgCl (s)

New Stuff: Ionic Equations One way that we can represent a reaction in solution is by using an ionic equation. An ionic equation shows which ions are separate (aqueous) in a reaction and which ions are together (solid).

→ Ionic Equations Reactants Products Ag+ (aq) Na+ (aq) Na+ (aq) NO3- (aq) Cl- (aq) NO3- (aq) AgCl (s) Ionic Equation Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) → Na+(aq) + NO3-(aq) + AgCl(s)

Practice Let’s try a practice ionic equation using the reaction between potassium hydroxide and magnesium bromide. First, write the balanced chemical equation for the reaction. 2 KOH(aq) + MgBr2(aq) → 2 KBr(aq) + Mg(OH)2(s)

Practice Remember, substances that are aqueous are actually dissociated. So in the ionic equation, we will show them separated. Solids remain together. 2 KOH(aq) + MgBr2(aq) → 2 KBr(aq) + Mg(OH)2(s) 2 K+(aq) + 2 OH-(aq) + Mg2+(aq) + 2 Br –(aq) → 2 K+(aq) + 2 Br --(aq) + Mg(OH)2(s)

One More Practice Write the ionic equation for the reaction between aqueous lithium sulfate and aqueous barium hydroxide Answer: 2 Li+(aq) + SO42-(aq) + Ba2+(aq) + 2 OH-(aq) → 2 Li+(aq) + 2 OH-(aq) + BaSO4(s)

Ion Accounting Let’s look more closely at that last ionic equation: 2 Li+(aq) + SO42-(aq) + Ba2+(aq) + 2 OH-(aq) → 2 Li+(aq) + 2 OH-(aq) + BaSO4(s) Do you see any reactants that didn’t really change in the reaction (i.e., they are the same in both the reactants and the products?)

Ion Accounting Let’s look more closely at that last ionic equation: 2 Li+(aq) + SO42-(aq) + Ba2+(aq) + 2 OH-(aq) → 2 Li+(aq) + 2 OH-(aq) + BaSO4(s) These substances are called spectator ions because they didn’t really do anything. They are the same both before and after the reaction.

Ion Accounting Let’s look more closely at that last ionic equation: 2 Li+(aq) + SO42-(aq) + Ba2+(aq) + 2 OH-(aq) → 2 Li+(aq) + 2 OH-(aq) + BaSO4(s) A way to simplify the ionic equation is to focus on what ions really reacted is to write a net ionic equation where we eliminate the spectator ions.

Net Ionic Equation Ionic Equation 2 Li+(aq) + SO42-(aq) + Ba2+(aq) + 2 OH-(aq) → 2 Li+(aq) + 2 OH-(aq) + BaSO4(s) Net Ionic Equation SO42-(aq) + Ba2+(aq) → BaSO4(s)

Practice Let’s try another one. Write the ionic and net ionic equations for the following chemical reaction: 3 (NH4)2CO3(aq) + 2 Fe(ClO4)3(aq) → Fe2(CO3)3(s) + 6 NH4ClO4(aq) Ionic Equation 6 NH4+(aq) + 3 CO32-(aq) + 2 Fe3+(aq) + 6 ClO4-(aq) → Fe2(CO3)3(s) + 6 NH4+(aq) + 6 ClO4-(aq) Net Ionic Equation 3 CO32-(aq) + 2 Fe3+(aq) → Fe2(CO3)3(s)

Practice Ok. Last one. Write the net ionic equation for the following chemical reaction: Sr(OH)2(aq) + Cu2SO4(aq) → SrSO4(s) + 2 CuOH(s) Net Ionic Equation Sr2+(aq) + 2 OH-(aq) + 2 Cu+(aq) + SO42-(aq) →