# Understanding Rate of Reaction

1. Rate of reaction is defined as the change in the amount of reactants or products per unit time.
2. It is a measure of how fast a reaction occurs.
1. Fast Reaction = Rate of reaction is high.
2. Slow Reaction = Rate of reaction is low
3. A fast reaction taken shorter time for the reaction to complete.

Example of fast reaction
 Type of Reaction Example Combustion Combustion of magnesium in oxygen $Mg+ O 2 →MgO$ Combustion of ethane (C2H6) $C 2 H 6 + 7 2 O 2 →2C O 2 +3 H 2 O$ Reaction between reactive metal and water Reaction between potassium and water $2K+2 H 2 O→2KOH+ H 2$ Reaction between metal carbonate and acid Reaction between limestone/ marble and sulphuric acid $CaC O 3 + H 2 S O 4 →CaS O 4 +C O 2 + H 2 O$ Ionic precipitation (Double decomposition) Precipitation of silver(I) chloride

Example of slow reaction
 Type of Reaction Example Photosynthesis Rusting Fermentation