Class 10 Science Notes
hapter 1: Chemical Reactions and
C
Equations
1.1 Chemical Reactions
chemical reactionis a process in which one or moresubstances (reactants) are transformed
A
into new substances (products) with different properties.
Indicators of a Chemical Reaction:
● Change in state
● Change in color
● Evolution of gas
● Change in temperature
● Formation of precipitate
Types of Chemical Reactions:
1. Combination Reaction– Two or more reactants combineto form a single product.
○ Example: CaO + H₂O → Ca(OH)₂
2. Decomposition Reaction– A single compound breaksdown into two or more products.
○ Example: 2H₂O₂ → 2H₂O + O₂
3. D
isplacement Reaction– A more reactive element replacesa less reactive element
from a compound.
○ Example: Zn + CuSO₄ → ZnSO₄ + Cu
, 4. D
ouble Displacement Reaction– Exchange of ions between two compounds to form
new compounds.
○ Example: AgNO₃ + NaCl → AgCl + NaNO₃
5. R
edox Reaction– Involves oxidation (loss of electrons)and reduction (gain of
electrons).
○ Example: CuO + H₂ → Cu + H₂O
1.2 Balancing Chemical Equations
A balanced chemical equation has an equal number of atoms of each element on both sides.
xample:Unbalanced: H₂ + O₂ → H₂O
E
Balanced: 2H₂ + O₂ → 2H₂O
aw of Conservation of Mass:Mass can neither be creatednor destroyed in a chemical
L
reaction.
Practice Questions:
Easy:
1. Define a chemical reaction with an example.
2. What are the signs of a chemical reaction?
oderate:3. Balance the following equation: Fe +H₂O → Fe₃O₄ + H₂ 4. Differentiate between
M
displacement and double displacement reactions with examples.
Hard:5. Explain the role of oxidation and reductionin redox reactions with an example.
Chapter 2: Acids, Bases, and Salts
2.1 Acids and Bases
hapter 1: Chemical Reactions and
C
Equations
1.1 Chemical Reactions
chemical reactionis a process in which one or moresubstances (reactants) are transformed
A
into new substances (products) with different properties.
Indicators of a Chemical Reaction:
● Change in state
● Change in color
● Evolution of gas
● Change in temperature
● Formation of precipitate
Types of Chemical Reactions:
1. Combination Reaction– Two or more reactants combineto form a single product.
○ Example: CaO + H₂O → Ca(OH)₂
2. Decomposition Reaction– A single compound breaksdown into two or more products.
○ Example: 2H₂O₂ → 2H₂O + O₂
3. D
isplacement Reaction– A more reactive element replacesa less reactive element
from a compound.
○ Example: Zn + CuSO₄ → ZnSO₄ + Cu
, 4. D
ouble Displacement Reaction– Exchange of ions between two compounds to form
new compounds.
○ Example: AgNO₃ + NaCl → AgCl + NaNO₃
5. R
edox Reaction– Involves oxidation (loss of electrons)and reduction (gain of
electrons).
○ Example: CuO + H₂ → Cu + H₂O
1.2 Balancing Chemical Equations
A balanced chemical equation has an equal number of atoms of each element on both sides.
xample:Unbalanced: H₂ + O₂ → H₂O
E
Balanced: 2H₂ + O₂ → 2H₂O
aw of Conservation of Mass:Mass can neither be creatednor destroyed in a chemical
L
reaction.
Practice Questions:
Easy:
1. Define a chemical reaction with an example.
2. What are the signs of a chemical reaction?
oderate:3. Balance the following equation: Fe +H₂O → Fe₃O₄ + H₂ 4. Differentiate between
M
displacement and double displacement reactions with examples.
Hard:5. Explain the role of oxidation and reductionin redox reactions with an example.
Chapter 2: Acids, Bases, and Salts
2.1 Acids and Bases
