Types of reactions
There are many chemical reactions, however, they can be classify into four general types: synthesis, decomposition, single replacement and double replacement reactions.
Synthesis or Combination Reaction
In a synthesis reaction two or more simple substances combine to form a more complex substance: Two or more reactants and only one product.
Ex: 2 H2 + O2 -----> 2 H2O
2 Reactants -----> 1 product
Decomposition Reaction
In a decomposition reaction one complex substance breaks down into its more simple parts. This is the opposite of a synthesis reaction. One reactant yields two or more products.
Ex: 2 H2O -----> 2 H2 + O2
1 reactant -----> 2 products
Single displacement reaction
In a single replacement reaction an uncombined element replaces another in a compound. Two reactants yield two products.
Ex: 2 HCl + Zn -----> ZnCl2 + H2
2 reactants ----->2 products
Double displacement reaction
In a double replacement reaction two elements forming part of two different compounds switch places to form a new compound. Two reactants yield two products.
Ex: HCl + NaOH ----->NaCl + H2O
2 reactants-----> 2 products
Synthesis or Combination Reaction
In a synthesis reaction two or more simple substances combine to form a more complex substance: Two or more reactants and only one product.
Ex: 2 H2 + O2 -----> 2 H2O
2 Reactants -----> 1 product
Decomposition Reaction
In a decomposition reaction one complex substance breaks down into its more simple parts. This is the opposite of a synthesis reaction. One reactant yields two or more products.
Ex: 2 H2O -----> 2 H2 + O2
1 reactant -----> 2 products
Single displacement reaction
In a single replacement reaction an uncombined element replaces another in a compound. Two reactants yield two products.
Ex: 2 HCl + Zn -----> ZnCl2 + H2
2 reactants ----->2 products
Double displacement reaction
In a double replacement reaction two elements forming part of two different compounds switch places to form a new compound. Two reactants yield two products.
Ex: HCl + NaOH ----->NaCl + H2O
2 reactants-----> 2 products
