Types of Chemical Reactions

Types of Chemical Reactions

1. Combination (Synthesis)

Two or more substances combine to form a new substance.

$A + B \rightarrow AB$

Example: $2H_2 + O_2 \rightarrow 2H_2O$ (Water formation)

2. Decomposition

A compound breaks down into simpler substances.

$AB \rightarrow A + B$

Example: $2H_2O \rightarrow 2H_2 + O_2$ (Electrolysis of water)

3. Single Replacement

One element replaces another in a compound.

$A + BC \rightarrow AC + B$

Example: $Zn + CuSO_4 \rightarrow ZnSO_4 + Cu$

4. Double Replacement

Two compounds exchange ions.

$AB + CD \rightarrow AD + CB$

5. Combustion

A substance reacts with oxygen, releasing heat and light.

$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$ (Burning methane)