Formula Sheet: Chemical Reactions and Equations
This chapter introduces chemical reactions and equations, detailing how substances transform during reactions and the significance of balanced equations.
Mathematical Derivations, Constant Metrics, and Variable Demystification Indices
All engineering, algebraic, and chemical glyph variables are rendered with complete structural precision for Class 10 Science.
Chemical Reactions and Equations – Formula & Equation Sheet
Essential formulas and equations from Science, tailored for Class X in Science.
This one-pager compiles key formulas and equations from the Chemical Reactions and Equations chapter of Science. Ideal for exam prep, quick reference, and solving time-bound numerical problems accurately.
Formula sheet
Key concepts & formulas
Essential formulas, key terms, and important concepts for quick reference and revision.
Formulas
Law of Conservation of Mass
In a chemical reaction, the total mass of the reactants equals the total mass of the products. This law is foundational for balancing chemical equations.
Combination Reaction: A + B → AB
Two or more substances combine to form a single product. Example: 2H₂ + O₂ → 2H₂O.
Decomposition Reaction: AB → A + B
A single compound breaks down into two or more simpler substances. Example: 2H₂O → 2H₂ + O₂.
Displacement Reaction: A + BC → AC + B
A more reactive element displaces a less reactive element from its compound. Example: Zn + CuSO₄ → ZnSO₄ + Cu.
Double Displacement Reaction: AB + CD → AD + CB
Ions exchange between two compounds to form new compounds. Example: BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl.
Exothermic Reaction
Reactions that release energy, usually in the form of heat. Example: C + O₂ → CO₂ + heat.
Endothermic Reaction
Reactions that absorb energy from the surroundings. Example: 2NH₄Cl + Ba(OH)₂ → BaCl₂ + 2NH₃ + 2H₂O.
Oxidation
Loss of electrons or gain of oxygen. Example: 2Mg + O₂ → 2MgO.
Reduction
Gain of electrons or loss of oxygen. Example: CuO + H₂ → Cu + H₂O.
Redox Reaction
A reaction where oxidation and reduction occur simultaneously. Example: Zn + CuSO₄ → ZnSO₄ + Cu.
Equations
Mg + O₂ → MgO
Magnesium reacts with oxygen to form magnesium oxide. This is a combination reaction.
2H₂O → 2H₂ + O₂
Water decomposes into hydrogen and oxygen gases when electricity is passed through it. This is an electrolysis reaction.
Fe + CuSO₄ → FeSO₄ + Cu
Iron displaces copper from copper sulphate solution, showcasing a displacement reaction.
Na₂SO₄ + BaCl₂ → BaSO₄ + 2NaCl
Sodium sulphate reacts with barium chloride to form barium sulphate (a precipitate) and sodium chloride, illustrating a double displacement reaction.
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy
Glucose reacts with oxygen to produce carbon dioxide, water, and energy, representing respiration as an exothermic reaction.
2AgCl → 2Ag + Cl₂
Silver chloride decomposes into silver and chlorine gas in the presence of sunlight, a photochemical decomposition reaction.
Pb(NO₃)₂ → PbO + 2NO₂ + O₂
Lead nitrate decomposes on heating to form lead oxide, nitrogen dioxide, and oxygen, a thermal decomposition reaction.
Zn + 2HCl → ZnCl₂ + H₂
Zinc reacts with hydrochloric acid to form zinc chloride and hydrogen gas, a single displacement reaction.
CuO + H₂ → Cu + H₂O
Copper oxide is reduced to copper by hydrogen, which is oxidized to water, a redox reaction.
2KBr + BaI₂ → 2KI + BaBr₂
Potassium bromide reacts with barium iodide to form potassium iodide and barium bromide, a double displacement reaction.
