Exploring Chemical Reactions and Equations with Future Classes
A chemical reaction and equation is a way of representing what happens when two or more substances interact. Chemical reactions involve the breaking and forming of chemical bonds, and the rearrangement of atoms. It is important to understand the concept of a chemical reaction and equation in order to understand basic chemistry. Notes, CBSE, and PDF downloads are available to help students learn more about chemical reactions and equations. PDF downloads can be found online, while CBSE notes can be found in many textbooks. With the help of these materials, students can learn the fundamentals of chemical reactions and equations.
Our website offers free PDF downloads for CBSE Class 10 Science notes covering topics such as Chemical Reactions and Equations. These notes provide a comprehensive overview of the topics, helping students to revise and prepare for exams. The PDF files are easy to download and print, making them ideal for studying on the go. Downloading from our website is secure and fast, so you can rest assured that you will have the latest and most accurate information.
CHAPTER-1 CHEMICAL REACTION AND EQUATIONS
Chemical reaction
The process in which new substances with new properties are formed from one or more substances is called Chemical Reaction.
A chemical reaction involves:
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Change in state or colour
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Change in temperature
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Evolution of gas
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Formation of precipitate
Examples:
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Digestion of food
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Respiration
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Rusting of iron
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Burning of Magnesium ribbon
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Formation of curd
Aqueous solution-
It is a solution in which solvent is water.
Chemical reaction
A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and formulae, wherein the reactant entities are given on the left-hand side and the product entities on the right-hand side.
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The substances that take part in a chemical reaction are called Reactants.
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The substances, which are form in a chemical reaction, is called Products.
TYPES OF CHEMICAL REACTIONS
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Combination reaction
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Decomposition reaction
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Thermal decomposition
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Electrolytic decomposition
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Photolytic decomposition
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Displacement reaction
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Double displacement
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Oxidation and reduction
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Exothermic reaction
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Endothermic reaction
COMBINATION REACTION:
The reaction in which two or more reactants combine to form a single product.
DECOMPOSITION REACTION:
A reaction in which a single reactant breaks down to form two or more products, is known as decomposition reaction.
Decomposition reaction is three types
Thermal decomposition:
These reactions involve the use of energy in the form of heat for decomposition of the reactant.
Calcium oxide is called lime or quick lime. It has many uses one is in manufacture of cement
Electrolytic Decomposition:
These reactions involve the use of electrical energy required for the decomposition of the reactant molecules.
Photolytic Decomposition:
These reactions involve the use of light energy for the purpose of decomposition.
The above reaction is used in black & white photography.
DISPLACEMENT REACTION:
The chemical reaction in which a more reactive element displaces a less reactive element from its salt solution.
The iron nail becomes brownish (in colour) by deposition of Cu and the blue colour of CuSO4 changes dirty green colour due to the formation of FeSO4.
Zinc and lead are more reactive elements than copper. They displace copper from its compounds.
DOUBLE DISPLACEMENT REACTION:
A reaction in which new compounds are formed by the exchange of ions between two compounds.
A white precipitate of BaSO4 is formed, so it is also called a precipitation reaction.
Precipitate
It is an insoluble solid that emerges from a liquid solution.
OXIDATION AND REDUCTION:
Oxidation: The addition of oxygen to a substance and the removal of hydrogen from a substance.
Reduction: The addition of hydrogen to a substance and the removal of oxygen from a substance.
REDOX REACTION –
In this reaction is reduced to Cu and H2 is oxidized to water. So, oxidation and reduction taking place together is a redox reaction.
​Some other examples
Effects of Oxidation in Daily Life
Corrosion –
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When a metal is exposed to substances such as moisture, acid, etc. for some time, a layer of hydrated oxide is formed which weakens the metal and hence metal is said to be corroded
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Rusting of iron, black coating on silver, and green coating on copper are examples of corrosion.
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Corrosion can be prevented by galvanization, electroplating, or painting.
Rusting of iron
Corrosion of iron is called rusting. Iron form hydrated iron oxide (rust) when kept open in moist air.
Formation of a green layer over copper
New copper (brown in colour) vessel forms a green layer of basic copper carbonate after some time due to the reaction of air and moisture.
Rancidity:
​The oxidation of fats and oils when exposed to air is known as rancidity. It leads to bad smell and bad taste of food.
Methods to Prevent Rancidity
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Keeping food in airtight containers
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Replacing air with nitrogen gas
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Refrigeration
Chemical reaction also classifies on the base of temperature
Exothermic Reactions:
The reaction in which heat is released along with the formation of products.
Endothermic Reactions:
The reactions which require energy in the form of heat, light, or electricity to break reactants are called endothermic reactions. Example decomposition reaction.
Extra reaction
