Decomposition reactions are said to be those reactions in which a reactants breakdown into two or more products. The general reaction for decomposition reactions is as follow,
ABC → A + B + C
Specific Examples are as,
Water → Hydrogen + Oxygen
2 H₂O → 2 H₂ + O₂
Calcium carbonate → Calcium oxide + Carbon dioxide
CaCO₃ → CaO + CO₂
While, Synthetic reactions are said to be those reactions in which two or more reactants combine to form two or more products. The general reaction for synthetic reactions is as follow,
A + B + C → ABC
Specific Examples are as,
Iron + Oxygen → Iron Oxide
2 Fe + 3 O₂ → 2 Fe₂O₃
Sodium + Chlorine → Sodium chloride
2 Na + Cl₂ → 2 NaCl
Sulfur + Oxygen → Sulfur dioxide
S + O₂ → SO₂
Potassium + Chlorine → Potassium chloride
2 K + Cl₂ → 2 KCl
