Types of Chemical Reactions
By: Michael McInroy
Synthesis
Definition: A reaction in which two or more substances react to form a single substance.
Equation: A + B -------> AB
Examples: 2Na + Cl2 --------> 2NaCl, 2H2 + O2 -------> 2H2O
Decomposition
Definition: A reaction in which a compound breaks down into two or more simpler substances.
Equation: AB --------> A + B
Examples: 2H2O --------> 2H2 + O2, CaCO3 ---------> CaO + CO2
Single-Replacement
Definition: A reaction in which one element takes the place of another element in a compound.
Equation: A + BC ---------> B + AC
Examples: Cu + 2AgNO3 ----------> 2Ag + Cu(NO3)2, 2K + 2H2O ----------> H2 + 2KOH
Double-Replacement
Definition: One in which two different compounds exchange positive ions and form two new compounds.
Equation: AB + CD --------> AD + CB
Examples: Pb(NO3)2 + 2KI --------> PbI2 + 2KNO3
Combustion
Definition: One in which a substance reacts rapidly with oxygen, often producing heat and light.
Equation: AB + C --------> AB + CD
Examples: CH4 + 2O2 -------> CO2 + 2H2O