Oxidation-Reduction ReactionsMetals – use the activity series or the Standard reduction tables
Nonmetals – use the activity table (easier)
Activity Series
Single Replacement Reactions of Metals
The more reactive metal will replace the less reactive metal within a compound
Example
Single Replacement Reactions
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
Predicting Products of Single Replacement Reactions
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
Practice Problems
Elements with Water
Very active metals will combine with water to form bases
Hydroxides
Very Reactive Nonmetals will react with water to form acids
Conditions will dictate which acid is formed.
Oxidizing Power of Acids
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)
Reactions of Metals with Acids
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.
Predicting Products of the Metal/Acid Reactions
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
Oxidizer!
Combustion is the adding of oxygen to carbon and hydrogen (and sulfur and nitrogen).
Reaction with metals form oxides
Reaction with nonmetals produce nonmetallic oxides
Oxides and Water
Soluble Metallic oxides
Example
Example
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
Metallic oxides and nonmetallic oxides will combine to form a salt
Example
Adding water makes hydroxides or oxides and hydrogen gas
Decomposition
Examples
Helpful Hints
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
Double replacement – acid/base or precipitate
Oxidation-Reduction – single replacement, combustion, decomposition (only one reactant), synthesis
If nothing else fits, use a simple redox reaction where the charges on the ions change.
Let’s Practice