In our daily life, we encounter a number of chemical reactions. The mere melting of an ice cube, boiling of water, burning of wood, smoke ejecting from vehicles-are all classic examples of common chemical reactions in our daily lives. In middle and high school chemistry, students are introduced to a large number of reactions. Students must understand that most of the chemical reactions follow a certain order, so, instead of just memorizing individual reactions, it is better to understand the way each group of reactions proceed, in order to form their desired products. This will make it easier to predict the products of a reaction in other similar cases. Examples of Common Chemical Reactions Every natural process is an example of a chemical reaction. A battery converts chemical energy into electrical energy, by virtue of some specific reaction. Similarly, burning a log of wood in the presence of oxygen is another reaction leading to the formation of products like carbon dioxide and heat energy. Some more reactions have been presented below. Synthesis or Combination Reaction This is the simplest reaction that occurs in nature. When two or more chemical elements or compounds react to form some specific product(s), it is called synthesis. It is in of the form: A + B → AB Examples

• Metal (Barium) + Oxygen → Metal Oxide (Barium Oxide): 2Ba + O₂ → 2BaO
• Nonmetal (Carbon) + Oxygen → Nonmetallic Oxide (Carbon Dioxide): C + O₂ → CO₂
• Metal Oxide (Calcium Oxide) + Water → Metallic Hydroxide (Calcium Hydroxide): CaO + H₂O → Ca(OH)₂
• Nonmetallic Oxide (Carbon Dioxide) + Water → Acid (Carbonic Acid): CO₂ + H₂O → H₂CO₃
• Metal (Calcium) + Nonmetal (Chlorine) → Salt (Calcium Chloride): Ca + Cl₂ → CaCl₂
• Nonmetal (Phosphorus) + Nonmetal (Chlorine) → Gaseous (Phosphorus Trichloride): 2P + 3Cl₂ → 2PCl₃

Decomposition Reaction In these reactions, a compound breaks into simpler ones. In general form, it is denoted as AB → A + B Example: The electrolysis reaction of water in which oxygen and hydrogen are formed as products: 2H₂O → 2H₂ + O₂ Single Displacement Reactions In these reactions, a more active element displaces or knocks out another less active element, from a compound. These reactions are of the form, A + BC → AC + B Example: Zn + CuSO₄ → ZnSO₄ + Cu Double Displacement Reactions When cations and anions of two different molecules are replaced, and two entirely different products are formed, the reaction is known as double displacement reaction. These reactions are of the type, AB + XY → AY + XB Example: Pb(NO₃)₂ + 2KI → PbI₂ + 2KNO₃ Acid Base Reaction An acid and a base when combined, form a salt and water. It is also called neutralization reaction. Acid + Base → Salt + Water Example: H₂SO₄ + NaOH → Na₂SO₄ + H₂O Some More Examples There are numerous other chemical reactions that are an integral part of life. They are as follows.

• Metal + Nonmetal → Salt: 2K + Cl₂ → 2KCl
• Metal1 + Salt → Metal2 + Salt: 2Na + CuSO₄ → Cu + Na₂SO₄
• Aerobic Respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂+ 6H₂O + Energy (36 ATPs)
• Anaerobic Respiration: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + Energy
• Photosynthesis: 6CO₂ + 6H₂O + Light energy → C₆H₁₂O₆ + 6O₂
• Rusting of Iron: Fe + O₂ + H₂O → Fe₂O₃. XH₂O

Common chemical reactions are mostly observed in our homes. Learning chemistry is fun, and if you start making a note of your surroundings at home, you'll be surprised to know that learning chemistry begins from our homes, rather than classrooms.