Classifying Chemical Reactions

Synthesis ReactionTwo or more reactants form a single product

Example:A + B AB2 Fe + 3 Cl2 2FeCl3

Combustion ReactionOxygen combines with a substance and releases energy in the form of heat and light (water is a product)

Examples:2 H2 + O2 2 H2OCH4 + 2O2 CO2 + 2 H2OAll reactions where a hydrocarbon reacts with oxygen will always form carbon dioxide and water as products

Decomposition ReactionSingle compound breaks down into two or more elements or compoundsExample:

AB A + BNH4NO3 N2O + 2 H2O

Single Replacement ReactionA reaction in which the atoms of one element replace the atoms of another element in a compound

Example:A + BX AX + B2 Li + 2 H2O 2 LiOH + H2

Metathesis (Double Replacement) ReactionExchange of ions between two compounds

Example:AX + BY AY + BXCa(OH)2 + 2 HCl CaCl2 + 2 H2O

Predicting Products of Chemical ReactionsClass of Reaction Reactants Products

Synthesis Two or more substances

One compound

Combustion A metal and oxygenA nonmetal and oxygenA compound and oxygen

The oxide of the metalThe oxide of the nonmetalTwo or more oxides(water is usually a product of all of these)

Decomposition One compound Two or more elements and/or compounds

Single-Replacement A metal and a compound

A nonmetal and a compound

A new compound and the replaced metalA new compound and the replaced nonmetal

Double-Replacement (Metathesis)

Two compounds Two different compounds, one of which is often a solid, water or a gas

Practice ProblemHow would you classify the following

chemical reaction?2 C4H10 + 13 O2 8 CO2 + 10 H2O

Answer: Combustion

Practice ProblemHow would you classify the following

reaction?Al + I2 AlI3

Answer: Synthesis

Practice ProblemHow would you classify the following reaction

AgNO3 + Na2S Ag2S + NaNO3

Answer: Metathesis (Double Replacement)

Practice ProblemPredict the products to the following

reaction.2 K + ZnCl2

Answer: Single Replacement2 KCl + Zn

Predict the products to the following chemical reaction.

2 NaN3

Answer:Decomposition3 N2 + 2 Na