Guides
Common Chemical Equations by Reaction Type
Frequently used equations grouped by reaction type for easy review. Pair them with the balancer and stoichiometry calculator to practise.
Combination (A + B → AB)
C + O₂ → CO₂ (ignite)
2H₂ + O₂ → 2H₂O (ignite)
3Fe + 2O₂ → Fe₃O₄ (ignite)
CaO + H₂O → Ca(OH)₂
Decomposition (AB → A + B)
2H₂O → 2H₂↑ + O₂↑ (electrolysis)
CaCO₃ → CaO + CO₂↑ (high temp.)
2KMnO₄ → K₂MnO₄ + MnO₂ + O₂↑ (Δ)
Single displacement
Zn + H₂SO₄ → ZnSO₄ + H₂↑
Fe + CuSO₄ → FeSO₄ + Cu
2Al + 6HCl → 2AlCl₃ + 3H₂↑
Double displacement
NaOH + HCl → NaCl + H₂O
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂↑
Na₂CO₃ + Ca(OH)₂ → CaCO₃↓ + 2NaOH
Unsure about coefficients? Check with the balancer; for amounts of reactants/products use the stoichiometry calculator.