SPM Chemistry

Understanding Rate of Reaction

spmchemistry
  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 \[2Mg + {O_2} \to 2MgO\] 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
Type of Reaction Example
Photosynthesis \[6C{O_2} + 6{H_2}O \to {C_6}{H_{12}}{O_6} + 6{O_2}\]
Rusting \[4Fe + 3{O_2} + 2{H_2}O \to 2F{e_2}{O_3} \bullet 2{H_2}O\]
Fermentation \[{C_6}{H_{12}}{O_6} \to 2{C_2}{H_5}OH + 2C{O_2}\]