Understanding Rate of Reaction

Rate of reaction is defined as the change in the amount of reactants or products per unit time.
It is a measure of how fast a reaction occurs.

Example of fast reaction

Type of Reaction	Example
Combustion	Combustion of magnesium in oxygen $2Mg + {O_2} \to 2MgO$ Combustion of ethane (C₂H₆) ${C_2}{H_6} + \frac{7}{2}{O_2} \to 2C{O_2} + 3{H_2}O$
Reaction between reactive metal and water	Reaction between potassium and water $2K + 2{H_2}O \to 2KOH + {H_2}$
Reaction between metal carbonate and acid	Reaction between limestone/ marble and sulphuric acid $\begin{gathered} CaC{O_3} + {H_2}S{O_4} \hfill \\ \to CaS{O_4} + C{O_2} + {H_2}O \hfill \\ \end{gathered}$
Ionic precipitation (Double decomposition)	Precipitation of silver(I) chloride $AgN{O_3} + HCl \to AgCl + HN{O_3}$

Example of slow reaction