Chemical Reactions and Equations
This section covers the fundamental concepts of chemical reactions and how they are represented through equations. A chemical reaction occurs when substances undergo a process leading to the transformation of their identities. The initial substances, known as reactants, transform into new substances called products. The section highlights the indications of a chemical reaction, such as changes in state, color, temperature, and gas evolution.
Key Types of Chemical Reactions
- Combination Reactions: Two or more substances combine to form a single product, exemplified by the reaction of calcium oxide with water to yield slaked lime.
- Decomposition Reactions: A single compound breaks down into two or more products, such as the thermal decomposition of ferrous sulfate into iron oxide and sulfur oxides.
- Displacement Reactions: One element displaces another in a compound, as seen when iron displaces copper from copper sulfate solution.
- Double Displacement Reactions: Ions exchange between two compounds to form new compounds, such as when barium chloride reacts with sodium sulfate.
Additionally, the importance of balancing chemical equations is emphasized, as it reflects the law of conservation of mass. The section also discusses oxidation and reduction reactions, where substances gain or lose oxygen. Lastly, the lesson covers concepts like corrosion and rancidity, highlighting their relevance in everyday life.