Chemical Reactions and Equations Class 10 Notes
A chemical reaction is a process by which one or more substances transform into new substances with unique properties. Atoms get rearranged during a reaction, existing bonds are broken, and new bonds between elements are formed to create new compounds. The equation for such a change lists the reactants on the right-hand side and the products on the left-hand side.
Chemical reactions surround us, from iron rusting to cooking. They assist in describing how energy changes take place in physical and biological processes.
Significant uses of chemical reactions are producing fertilizers, fuels, and drugs. Natural processes such as respiration, digestion, and photosynthesis also rely on chemical reactions to keep life going.
Chemical Reactions and Equations Class 10 Notes
Chemical reactions and equations form the foundation of chemistry. They explain how substances interact to form new products with different properties. These notes simplify key ideas like reactants, products, types of reactions, and how to write balanced chemical equations.
What Is a Chemical Reaction?
A chemical reaction occurs when one or more substances (reactants) change to form new substances (products) with different physical and chemical properties. Examples include rusting of iron, burning of wood, or digestion of food.
During a chemical reaction, chemical bonds between atoms break, and new bonds form to create new compounds. These changes are represented using chemical equations to clearly show what happens in the reaction.
Writing a Chemical Equation
A chemical equation uses chemical symbols and formulas to represent a reaction. For example,
Magnesium + Oxygen → Magnesium Oxide
This can be written as:
Mg + O₂ → MgO
However, this equation is not balanced because the number of atoms on both sides is unequal. To satisfy the Law of Conservation of Mass, the number of atoms of each element must be equal on both sides.
Balanced equation: 2Mg + O₂ → 2MgO
Types of Chemical Reactions
Types of chemical reactions include:
- Combination Reaction: Two or more substances combine to form a single product.
Example: H₂ + Cl₂ → 2HCl - Decomposition Reaction: A compound breaks down into simpler substances.
Example: 2H₂O → 2H₂ + O₂ - Displacement Reaction: One element replaces another in a compound.
Example: Zn + CuSO₄ → ZnSO₄ + Cu - Double Displacement Reaction: Exchange of ions between two compounds occurs.
Example: Na₂SO₄ + BaCl₂ → 2NaCl + BaSO₄ - Oxidation and Reduction (Redox Reactions):
- Oxidation: Addition of oxygen or removal of hydrogen.
- Reduction: Addition of hydrogen or removal of oxygen.
