1. LEARN THESE DIATOMIC MOLECULES: O2 H2 N2 F2 Cl2 Br2 I2 2. The same number of atoms of each element
appearing in reactants must appear in the products.
3. The subscripts of a formula cannot be changed to balance the equation. Each compound must retain its stableness via oxidation states.
4. Choose compound with greatest number of atoms first.
5. Balance by placing necessary coefficients in front of entire molecules. NO SUBSCRIPT CHANGES!
6. Be certain each side of equation has same number of atoms of each type.
7. Make sure coefficients are in lowest whole number ratios.
8. Polyatomic ions usually stay intact, but multiple polyatomic ions may be separated.
9. (aq.) stands for aqueous which is Latin for water solution:
(g) gas (l) liquid (s) solid (c) crystalline solid
means “yields” and shows direction of action
∆ above arrow shows heat has been added
shows reaction is reversible
MINOH: try Metals first, then Ions, then Nonmetals, and Oxygen, then Hydrogen last
C8H18 + O2 CO2 + H2O C8H18 + O2 __ CO2 + __ H2O
C8H18 + __ O2 __ CO2 + __ H2O
__ C8H18 + __ O2 __ CO2 + __ H2O
H2CrO4 + AgNO3 Ag2CrO4 + HNO3 (aq) (aq) (s)
(aq)
Chromic + Silver Silver + Nitric
Acid Nitrate Chromate Acid
1, 2, 1, 2 Double displacement
Cu(NO3)2 CuO + NO2 + O2 (aq) (s) (g)
(g)
Copper (II) Copper (II) + Nitrogen + Oxygen
Nitrate Oxide Dioxide Gas
2, 2, 4, 1 Decomposition
AlBr3 + Cl2 AlCl3 + Br2 (aq) (g) (aq) (g)
Aluminum + Chlorine Aluminum + Bromine
Bromide Gas Chloride Gas
2, 3, 2, 3 Single Displacement
P4 + O2 + H2O H3PO4 (s) (g) (aq) (aq)
Phosphorus + Oxygen + Water Phosphoric
(free) gas acid
1, 5, 6, 4 Synthesis
sodium permanganate + sulfuric acid sodium sulfate + manganese (VII) oxide + water
NaMnO4 + H2SO4 Na2SO4 + Mn2O7 + H2O
(aq) (aq) (aq) (s) (l)
2, 1, 1, 1, 1 Double Displacement
Th(NO3)4 + K3PO4 Th3(PO4)4 + KNO3 (aq) (aq) (s)
(aq)
Thorium + Potassium Thorium + Potassium
Nitrate Phosphate Phosphate Nitrate
3, 4, 1, 12 Double Displacement
sulfur trioxide + nitric acid sulfuric acid + dinitrogen pentoxide
SO3 + HNO3 H2SO4 + N2O5 (g) (aq) (aq) (g)
1, 2, 1, 1 Double Displacement
NH4NO3 + Ca(OH)2 Ca(NO3)2 + NH3 + H2O (aq) (aq) (aq) (g)
(l)
Ammonium + Calcium Calcium + Ammonia + water
Nitrate Hydroxide Nitrate
2, 1, 1, 2, 2 Double Displacement
sodium chloride + potassium iodide
NaCl + KI ________ + _________ (aq) (aq) (?)
(?)
Does a reaction take place?
CuSO4 + H3PO4 _____ + ______ (aq) (aq)
A)3, 1, 2, 1B)3, 1, 1, 3C)2, 3, 3, 2D)3, 2, 1, 3E)2, 3, 3, 1
((D))Copper (II) + Phosphoric Copper (II) +
SulfuricSulfate Acid Phosphate
Acid
Mg(OH)2 + H3PO4 _____ + ______ (aq) (aq)A.1, 1, 1, 1B.3, 2, 1, 3C.2, 3, 1, 6D.2, 3, 1, 1E.3, 2, 1, 6
((E.))Magnesium + Phosphoric Magnesium +
WaterHydroxide Acid Phosphate
CuCl2 + Na3PO4 _____ + ______ (aq) (aq)A.1, 2, 1, 2B.2, 3, 1, 6C.2, 3, 1, 1D.3, 2, 1, 6E. 1, 1, 1, 1
((D))Copper (II) + Sodium Copper (II) +
SodiumChloride Phosphate Phosphate
Chloride
Potassium + Nickel (II) _____ + ______
Permanganate NitrateA.2, 1, 2, 1B.2, 1, 3, 1C.1, 2, 1, 2D.1, 2, 1, 3E. 1, 1, 1, 1
((A))KMnO4 + Ni(NO3)2 KNO3 + Ni(MnO4)2