Predicting Products of Reactions
AP Chemistry
Ms. Paskowski

More reactive element will replace a less
reactive element
 Metals
– use the activity series or the
Standard reduction tables
 Nonmetals
(easier)
– use the activity table
 The
more reactive metal will replace the
less reactive metal within a compound
 Example
• Zn (s) + CuSO4  Cu (s) + ZnSO4
 The
more reactive zinc replaces copper.
STANDARD REDUCTION
POTENTIALS



All reactions listed are
reduction reactions.
The reactions most likely to
occur have the largest
positive value.
The more positive, the more
likely to be reduced
M
+ AB or N + CD
 where M = metal and N = Nonmetal
 Use
Activity table to determine whether
• M is more active than A or less likely to be
reduced, if so a reaction will occur.
• N is more active than D or more likely to be
reduced, if so a reaction will occur
 Chemistry: Matter
and Its Changes
• Page 224 #5.50 and 5.51
 Very
active metals will combine with
water to form bases
• Hydroxides
• Often produce hydrogen gas
 Very
Reactive Nonmetals will react with
water to form acids
• Conditions will dictate which acid is formed.
 Nonoxidizing
acids– i.e. HCl, HBr
• Hydrogen will be replaced by a more active
metal. H will be reduced and the metal will be
oxidized. Anion does not participate
 Oxidizing
Acids always contain oxygen.
• Anion is sometimes a stronger oxidizer than H+
• i.e. HNO3, H2SO4 (under certain conditions)
 Acids
will react with active metals
 Using
the Standard Reduction Potential
table
• If the reduction value is negative , the metal will
replace the H in the acid and Hydrogen gas will
be produced.
• If the reduction value is positive, no reaction will
occur.
 For
anoxy acids, the products are a salt and
hydrogen gas
• M + HA  MA + H2
 For
oxoacids, the products are a salt, water,
and a gas
• M + HAxOy  H2O + M+ + AzOq
 Practice Problems
• Page 224 # 46-49
 Oxidizer!
• Combustion is the adding of oxygen to carbon
and hydrogen (and sulfur and nitrogen).
 Reaction
 Reaction
with metals form oxides
with nonmetals produce
nonmetallic oxides
 Soluble
Metallic oxides
• MxOy produce bases (hydroxides) when
dissolved in water
 Example
 NaOH + H2O  Na+ + OH-
 Nonmetallic
oxides
• Produce acids when dissolved in water
• Example
 N2O5 + H2O  H+ + NO3 –
 Metallic
oxides plus acid
• Produce a salt and water
 Metallic oxides are weak bases and will react with the
acid to produce salt and water
 Nonmetallic
oxides plus bases
• Nonmetallic oxides are acidic
• Produce a salt and water
 Nonmetallic oxides are weak acids and will react with
the base to produce salt and water
 Metallic
oxides and nonmetallic oxides
will combine to form a salt
 Example
• MgO + CO2  MgCO3
• CaO + SO3  CaSO4
 Metals
plus nonmetals
• Adding Hydrogen makes hydrides
• Adding halogens makes halides
• Adding nitrogen makes nitrides
• Adding sulfur makes sulfides
• Adding oxygen makes oxides
 Adding LOTS of oxygen makes peroxides
• Adding water makes hydroxides or oxides and
hydrogen gas
 Problems
given will usually produce a
oxygen or water
 Examples
• CaCO3  CaO + CO2
• H2O2  H2O + O2
• KClO3  KCl + O2
• Al(OH)3  Al2O3 + H2O
1)
2)
Write all the species down in their
physical state, i.e. liquid, solid, gas, or ions
in solution
Determine the type of reaction that could
occur
1) Double replacement – acid/base or precipitate
2) Oxidation-Reduction – single replacement,
combustion, decomposition (only one reactant),
synthesis
3) If nothing else fits, use a simple redox reaction
where the charges on the ions change.