Class 10 Science – Chapter 1
Chemical Reactions and Equations
Chemical reactions are the changes in which one or more substances combine to
form new substances. This chapter explains chemical equations, balancing
equations, types of reactions, oxidation, reduction, and corrosion with examples
from daily life.
Introduction to Chemical Reactions
A chemical reaction is a process in which new substances are formed. During a
chemical reaction, the properties of products become different from the reactants.
Common observations are: • Change in state • Change in colour • Evolution of gas •
Formation of precipitate • Change in temperature Examples: 1. Burning magnesium
ribbon 2. Rusting of iron 3. Digestion of food
A chemical reaction is a process in which new substances are formed. During a
chemical reaction, the properties of products become different from the reactants.
Common observations are: • Change in state • Change in colour • Evolution of gas •
Formation of precipitate • Change in temperature Examples: 1. Burning magnesium
ribbon 2. Rusting of iron 3. Digestion of food
Chemical Equations
A chemical equation represents a chemical reaction using symbols and formulas.
Example: Magnesium + Oxygen → Magnesium oxide 2Mg + O■ → 2MgO The
substances on the left side are called reactants and on the right side are called
products.
, A chemical equation represents a chemical reaction using symbols and formulas.
Example: Magnesium + Oxygen → Magnesium oxide 2Mg + O■ → 2MgO The
substances on the left side are called reactants and on the right side are called
products.
Balanced Chemical Equation
A balanced chemical equation has an equal number of atoms of each element on
both sides. Law of conservation of mass states that mass can neither be created
nor destroyed. Example: Fe + H■O → Fe■O■ + H■ Balanced equation: 3Fe +
4H■O → Fe■O■ + 4H■
A balanced chemical equation has an equal number of atoms of each element on
both sides. Law of conservation of mass states that mass can neither be created
nor destroyed. Example: Fe + H■O → Fe■O■ + H■ Balanced equation: 3Fe +
4H■O → Fe■O■ + 4H■
Types of Chemical Reactions
There are different types of chemical reactions: 1. Combination reaction 2.
Decomposition reaction 3. Displacement reaction 4. Double displacement reaction
5. Redox reaction
There are different types of chemical reactions: 1. Combination reaction 2.
Decomposition reaction 3. Displacement reaction 4. Double displacement reaction
5. Redox reaction
Combination Reaction
When two or more substances combine to form a single product, it is called a
combination reaction. Example: CaO + H■O → Ca(OH)■ + Heat This reaction
Chemical Reactions and Equations
Chemical reactions are the changes in which one or more substances combine to
form new substances. This chapter explains chemical equations, balancing
equations, types of reactions, oxidation, reduction, and corrosion with examples
from daily life.
Introduction to Chemical Reactions
A chemical reaction is a process in which new substances are formed. During a
chemical reaction, the properties of products become different from the reactants.
Common observations are: • Change in state • Change in colour • Evolution of gas •
Formation of precipitate • Change in temperature Examples: 1. Burning magnesium
ribbon 2. Rusting of iron 3. Digestion of food
A chemical reaction is a process in which new substances are formed. During a
chemical reaction, the properties of products become different from the reactants.
Common observations are: • Change in state • Change in colour • Evolution of gas •
Formation of precipitate • Change in temperature Examples: 1. Burning magnesium
ribbon 2. Rusting of iron 3. Digestion of food
Chemical Equations
A chemical equation represents a chemical reaction using symbols and formulas.
Example: Magnesium + Oxygen → Magnesium oxide 2Mg + O■ → 2MgO The
substances on the left side are called reactants and on the right side are called
products.
, A chemical equation represents a chemical reaction using symbols and formulas.
Example: Magnesium + Oxygen → Magnesium oxide 2Mg + O■ → 2MgO The
substances on the left side are called reactants and on the right side are called
products.
Balanced Chemical Equation
A balanced chemical equation has an equal number of atoms of each element on
both sides. Law of conservation of mass states that mass can neither be created
nor destroyed. Example: Fe + H■O → Fe■O■ + H■ Balanced equation: 3Fe +
4H■O → Fe■O■ + 4H■
A balanced chemical equation has an equal number of atoms of each element on
both sides. Law of conservation of mass states that mass can neither be created
nor destroyed. Example: Fe + H■O → Fe■O■ + H■ Balanced equation: 3Fe +
4H■O → Fe■O■ + 4H■
Types of Chemical Reactions
There are different types of chemical reactions: 1. Combination reaction 2.
Decomposition reaction 3. Displacement reaction 4. Double displacement reaction
5. Redox reaction
There are different types of chemical reactions: 1. Combination reaction 2.
Decomposition reaction 3. Displacement reaction 4. Double displacement reaction
5. Redox reaction
Combination Reaction
When two or more substances combine to form a single product, it is called a
combination reaction. Example: CaO + H■O → Ca(OH)■ + Heat This reaction
