Chemical Reactions and Equations – Class 10 Science Chapter 1 | Deus Learnings
Chemical Reactions and Equations
Chapter Basics: Topics & Subtopics
1. Introduction to Chemical Reactions
- Definition: Process where reactants transform into new products.
- Signs of Reaction: Change in state, change in colour, evolution of gas, change in temperature.
- Common Examples: Souring of milk, rusting of iron, fermentation of grapes, digestion of food.
2. Chemical Equations
- Writing Equations: Representing reactions using symbols and formulae (LHS = Reactants, RHS = Products).
- Balanced Chemical Equations: Equalizing the number of atoms of each element on both sides to satisfy the Law of Conservation of Mass.
3. Types of Chemical Reactions
- Combination Reaction: Two or more reactants combine to form a single product. (Includes Exothermic reactions).
- Decomposition Reaction: A single reactant breaks down into simpler products.
- Thermal Decomposition: Using heat (e.g., Limestone to Quicklime).
- Electrolytic Decomposition: Using electricity (e.g., Electrolysis of water).
- Photolytic Decomposition: Using light (e.g., Silver chloride in sunlight).
- Displacement Reaction: A more reactive element displaces a less reactive element from its compound.
- Double Displacement Reaction: Exchange of ions between two compounds (often forming a precipitate).
4. Oxidation and Reduction
- Oxidation: Gain of oxygen or loss of hydrogen (or loss of electrons).
- Reduction: Loss of oxygen or gain of hydrogen (or gain of electrons).
- Redox Reactions: Reactions where oxidation and reduction occur simultaneously.
- Everyday Examples:
- Corrosion: Damage to metals (e.g., Rusting).
- Rancidity: Oxidation of fats and oils leading to bad smell/taste.
