What is a Chemical Reaction?
A chemical reaction is a process of rearrangement of the molecular or ionic structure of elements to form a new substance. The new combination of elements formed shows different physical and chemical properties.
Another definition of chemistry reaction is: It is a process in which two or more chemical compounds undergo an atomic level reaction to form new compounds with different physical and chemical properties. The compounds which undergo the reaction are called the reactants, and the new chemical compounds formed after the reaction has taken place are called the products.
A chemical equation, on the other hand, is just a written representation of the process that occurs during a chemical reaction. A chemical equation involves the use of numbers and specific chemical symbols.
Important Concepts You Will Learn in Chemistry Reactions
What are chemical reactions?
What are chemical equations?
Characteristics of a chemical reaction
Types of chemical reactions and their properties
Examples of chemical reactions
Common chemical reactions observed in daily life and their equations
Importance of Chemistry reactions
What is the Importance of Chemical Reactions?
Chemical reactions are the basis of life on Earth. Without chemical reactions, the bodies of all living beings would not be able to perform basic life functions and no life would exist on Earth. So, what makes chemistry reactions important?
Chemical reactions enable the formation of new forms of matter and identifying unknown specimens.
For synthesising new compounds like medicines, skin care products, soap or detergents, etc.
Using chemical reactions and equations, only we can understand the different physical and chemical properties of matter.
Biological processes like turning food into energy, sunlight into food, etc. are possible only because of chemical reactions between them.
Daily activities like washing clothes with soap, baking bread using fermentation, cooking food, etc. all involve chemical reactions.
The study of outer space and other planets is also possible only because of chemical reactions that are inferred by scientists.
Conclusion
Thus, this article taught us about chemistry reactions, how to define chemical reactions and equations, the types of chemical reactions, their examples, and importance of chemistry equations. We hope that now you will be able to differentiate between different types of chemical reactions easily.
Also, going through this article thoroughly will provide you with an in-depth explanation of one of the most basic and important topics of Chemistry. So, get your hands on this free study resource today.
FAQs on Chemical Reactions and Equations
1. What is the fundamental difference between a chemical reaction and a chemical equation?
A chemical reaction is the actual physical process where substances, known as reactants, are transformed into new substances called products through the breaking and forming of chemical bonds. In contrast, a chemical equation is the symbolic, written representation of that reaction. It uses chemical formulas and symbols to show the reactants, products, and the direction of the reaction, providing a shorthand summary of the process.
2. What are the primary types of chemical reactions a student should know for the CBSE Class 10 syllabus?
According to the CBSE syllabus for the 2025-26 session, students should focus on understanding the following major types of chemical reactions:
- Combination Reaction: Two or more reactants combine to form a single product.
- Decomposition Reaction: A single compound breaks down into two or more simpler substances.
- Displacement Reaction: A more reactive element displaces a less reactive element from its compound.
- Double Displacement Reaction: An exchange of ions occurs between two compounds, often forming a precipitate.
- Oxidation-Reduction (Redox) Reaction: A reaction involving the simultaneous transfer of electrons, where one substance is oxidised and another is reduced.
3. Why is balancing a chemical equation a non-negotiable step in chemistry?
Balancing a chemical equation is essential because it must adhere to the Law of Conservation of Mass. This fundamental law states that matter cannot be created or destroyed in a chemical reaction. Therefore, a balanced equation ensures that the number of atoms of each element on the reactant side is exactly equal to the number of atoms of that same element on the product side, accurately reflecting what happens in nature.
4. What are the common observable signs that indicate a chemical reaction has taken place?
You can often tell a chemical reaction has occurred by observing one or more of these key indicators:
- Change in State: A solid, liquid, or gas is formed from different states (e.g., solid precipitate forming in a liquid).
- Change in Colour: The resulting solution or substance has a different colour than the reactants.
- Evolution of a Gas: Bubbles or fumes are produced.
- Change in Temperature: The reaction mixture becomes noticeably hotter (exothermic) or colder (endothermic).
5. How can one distinguish between a displacement and a double displacement reaction just by looking at the reactants?
You can typically distinguish them by the number and type of reactants. A displacement reaction usually involves an element reacting with a compound (e.g., Fe + CuSO₄). In contrast, a double displacement reaction involves two compounds reacting with each other, leading to an exchange of ions (e.g., Na₂SO₄ + BaCl₂). The key difference is an element displacing another in the first, versus an ion exchange between two compounds in the second.
6. What is the real-world significance of oxidation-reduction (redox) reactions?
Redox reactions are fundamental to many processes essential for life and technology. For example, cellular respiration, the process our bodies use to get energy from food, is a complex redox reaction. Other critical examples include photosynthesis in plants, the functioning of batteries and fuel cells, the process of combustion (burning), and undesirable processes like the rusting of iron and corrosion of metals.
7. Can a chemical reaction be both a decomposition and a redox reaction? Explain with an example.
Yes, a reaction can be classified in multiple ways. For instance, the electrolysis of water (2H₂O → 2H₂ + O₂) is a decomposition reaction because a single compound (water) breaks down into simpler substances (hydrogen and oxygen). It is also a redox reaction because the oxidation state of oxygen changes from -2 in H₂O to 0 in O₂ (oxidation), and the oxidation state of hydrogen changes from +1 in H₂O to 0 in H₂ (reduction).
8. What is the difference between exothermic and endothermic reactions?
The key difference lies in the flow of energy. An exothermic reaction is a chemical reaction that releases energy into the surroundings, usually in the form of heat, causing the temperature of the surroundings to rise. A common example is the burning of methane. Conversely, an endothermic reaction absorbs energy from the surroundings to proceed, causing the temperature of the surroundings to drop. The decomposition of calcium carbonate by heating is a classic example.
