Overview of Chemical Reactions
During a chemical reaction, reactants—starting substances—undergo a transformation to form products, new substances. This occurs through the breaking of existing chemical bonds and the formation of new ones, rearranging atoms while conserving both mass and the total number of atoms involved. The process is driven by collisions between molecules, often requiring activation energy to initiate.
Key Principles and Components
Chemical reactions follow principles like the law of conservation of mass, ensuring no atoms are created or destroyed. Components include reactants and products, catalysts that speed up reactions without being consumed, and energy changes—exothermic reactions release heat, while endothermic ones absorb it. Reaction rates depend on factors such as temperature, concentration, and surface area.
Practical Example: Rusting of Iron
A common example is the rusting of iron, represented as 4Fe + 3O₂ → 2Fe₂O₃. Here, iron atoms (Fe) react with oxygen molecules (O₂) from the air in the presence of water. Bonds between iron atoms break, and new bonds form with oxygen, creating iron oxide (rust). This slow reaction illustrates oxidation, where electrons are transferred, leading to visible corrosion over time.
Importance and Real-World Applications
Chemical reactions are fundamental to life processes like respiration and photosynthesis, industrial manufacturing such as producing plastics and fuels, and environmental phenomena like acid rain. Understanding them enables advancements in medicine, energy production, and materials science, while helping mitigate issues like pollution through controlled reactions.