Types of Chemical Reactions

1. Synthesis reactions 
   Two or more reactants combine to make 1 new product.
   Examples:
   C(s) + O₂(g) → CO₂(g)
   H₂O(l) + SO₃(g) → H₂SO₄(aq)
2. Decomposition reactions
   A single reactant breaks down to form 2 or more products.
   Examples:
   H²CO₃(aq) → H₂O(l) + CO₂(g)
   CaCO₃(s) → CaO(s) + CO₂(g)
3. Single-replacement reactions
   A single element replaces a similar element of an adjacent reactant compound.
   Examples:
   Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)
4. Double-replacement reactions 
   Two ionic compounds exchange ions, producing 2 new ionic compounds.
   Examples:
   NaCl(aq) AgNO₃(aq) → NaNO₃(aq) + AgCl(s)
   HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l)
5. Combustion reactions
   A hydrocarbon combines with oxygen gas releasing energy and burning to form carbon dioxide and water.
   Examples:
   Photosynthesis: C₆H₁₂O₆ (s) + 6O₂(g) à 6CO2(g) + 6H₂O(g)