Pb2+NO3

1–

Na1+ I1–

Ions in Aqueous Solutions

Pb(NO3)2(s) Pb(NO3)2(aq)

Pb2+(aq) + 2 NO31–(aq)

addwater

NaI(s)

+ H2O(aq)

Dissociation:

+ H2O(aq)

Na1+(aq) + I1–(aq)

Mix them and get…

NaI(aq)

NO31–

Pb2+

NO31–

NO31–

Ions in solution

Na1+ I1– Ions in solution

addwater

Molecular Equation

Molecular Equation

Mix them together and get…

Pb2+(aq) + 2 NO31–(aq) + 2 Na1+(aq) + 2 I1–(aq) PbI2(s) + 2 NO3

1–(aq) + 2 Na1+(aq)

Pb2+(aq) + 2 I1–(aq) PbI2(s)

Pb(NO3)2(aq) + 2 NaI(aq) PbI2(s) + 2 NO31–(aq) + 2 Na1+(aq)

Balance to get overall ionic equation…

Cancel spectator ions to get net ionic equation…

solid

in solution

Pb2+NO3

1–

Na1+ I1–

NO31–

Na1+ I1–

Pb2+

NO31–

Na1+

I1–

NO31–

Na1+

I1–

Ba2+

OH1–

OH1–

NO31–

NO31–

Mix together Zn(NO3)2(aq) and Ba(OH)2(aq):

Zn2+(aq) + 2 NO31–(aq) Ba2+(aq) + 2 OH1–(aq)

Ba(OH)2(aq)Zn(NO3)2(aq)

Balance to get overall ionic equation…

Zn2+

Zn(NO3)2(aq) + Ba(OH)2(aq) Zn(OH)2(s) + 2 NO31–(aq) + Ba2+(aq)

Zn2+(aq) + 2 NO31–(aq) + Ba2+(aq) + 2OH1–(aq) Zn(OH)2(s) + 2 NO3

1–(aq) + Ba2+(aq)

Mix them and get…

Zn2+(aq) + 2 OH1–(aq) Zn(OH)2(s)

Cancel spectator ions to get net ionic equation…

Acid-Base (Neutralization): an acid and base form salts and water.

ie. HClHCl(aq)(aq) + NaOH + NaOH(aq)(aq) NaCl NaCl(aq)(aq) + H + H22OO

Gas Evolution: reaction where a gas is formed.ie. HH22SOSO44(aq)(aq) + Li + Li22SS(aq)(aq) H H22SS(g)(g) + Li + Li22SOSO44(aq)(aq)

Precipitation: a precipitate is formed from two soluble substances.

ie. 2KI2KI(aq)(aq) + Pb(NO + Pb(NO33))22(aq)(aq) PbI PbI22(s)(s) + 2KNO + 2KNO33(aq)(aq)

Redox Reactions: How They Work

1. 2Mg (s) + O2 (g) → 2MgO (s)

Each Mg loses 2 e-; Each O gains 2 e-

2. Ca (s) + Cl2 (g) → CaCl2 (s)

Ca loses 2 e-; Each Cl gains 1 e-

3. Zn (s) + Fe2+ (aq) → Zn2+ (aq) + Fe (s) Zn loses 2 e-; Fe gains 2 e-