Structural Biochemistry/Reaction types

Types of chemical reactions

Synthesis
In a synthesis reaction, two or more reactants combine to form one complex product. The general equation to represent this reaction is: A + B→AB

Decomposition
The decomposition reaction is the opposite of the synthesis reaction. A complex compound breaks down into simpler substances. The general equation to represent this reaction is: AB→ A + B

Dissociation
Dissociation looks like and can be mistaken for decomposition but they are very different reactions. When a compound dissociates, it breaks down into ions instead of atoms. The products are therefore charged. The general equation looks like: AB→ A+ + B-

Single Replacement
A non-combined element replaces another in a compound and the element that it replaces has to be of the same group (e.g.metal replaces metal). The general equation: A + BC→ AC + B

Double Replacement
In a double replacement, two compounds each trade one element of the same type over to the other. The general equation: AB + CD→ AC + BD

Combustion
In a combustion reaction, a compound is combined with oxygen to produce carbon dioxide and water as products. Example: CnHx + O2→CO2 + H2O

Acid-Base
The acid base reaction is a type of double replacement reaction. When the acid and base react, the H+ ion reacts with the OH- ion to form H2O (water). The products of this reaction are typically water and an ionic salt. HA + BOH→ H2O + BA