Chemistry is one of the most important subjects for Bihar Board Class 10 students. The subject explains the composition of matter, chemical reactions, equations, and practical applications in daily life. For board exams, students need quick revision notes that cover all chapters, key concepts, formulas, and examples.
This blog provides a chapter-wise Chemistry revision guide for Bihar Board Class 10 Chemistry. It is written in simple English for easy understanding, yet detailed enough to help you score maximum marks.
Table of Contents
ToggleBihar Board Class 10 Chemistry Notes 2025 | All Chapters, Formulas & MCQs
Chapter 1: Chemical Reactions and Equations
Key Topics
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Chemical Reaction
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Types of Reactions
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Balancing Equations
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Examples
Chemical Reaction
A process in which one or more substances (reactants) change to form new substances (products) with different properties.
General Form:
Reactants → Products
Example:
2H2+O2→2H2O2H2+O2→2H2O
Types of Chemical Reactions
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Combination Reaction – Two or more substances combine to form a single product.
Example: CaO+H2O→Ca(OH)2CaO+H2O→Ca(OH)2 -
Decomposition Reaction – A single compound breaks into two or more substances.
Example: 2KClO3→2KCl+3O22KClO3→2KCl+3O2 -
Displacement Reaction – A more reactive element displaces a less reactive one.
Example: Zn+CuSO4→ZnSO4+CuZn+CuSO4→ZnSO4+Cu -
Double Displacement Reaction – Exchange of ions between two compounds.
Example: Na2SO4+BaCl2→BaSO4+2NaClNa2SO4+BaCl2→BaSO4+2NaCl -
Oxidation and Reduction
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Oxidation = Gain of Oxygen / Loss of Hydrogen
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Reduction = Loss of Oxygen / Gain of Hydrogen
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Chapter 2: Acids, Bases and Salts
Acids
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Sour in taste, turn blue litmus red.
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Produce H⁺ ions in solution.
Example: HCl, H₂SO₄
Bases
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Bitter in taste, soapy to touch, turn red litmus blue.
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Produce OH⁻ ions in solution.
Example: NaOH, KOH
Salts
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Formed by neutralization reaction between acid and base.
Example: HCl + NaOH → NaCl + H₂O
Important Reactions
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Reaction of Acids with Metals
Zn+H2SO4→ZnSO4+H2Zn+H2SO4→ZnSO4+H2 -
Neutralization
HCl+NaOH→NaCl+H2OHCl+NaOH→NaCl+H2O -
Reaction of Carbonates with Acids
CaCO3+2HCl→CaCl2+CO2+H2OCaCO3+2HCl→CaCl2+CO2+H2O
pH Scale
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Measures acidity/basicity (0–14).
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pH < 7 → Acidic, pH = 7 → Neutral, pH > 7 → Basic.
Chapter 3: Metals and Non-Metals
Physical Properties of Metals
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Malleable, ductile, good conductors, lustrous.
Physical Properties of Non-Metals
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Brittle, poor conductors, non-lustrous.
Chemical Properties of Metals
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Reaction with Oxygen
4Na+O2→2Na2O4Na+O2→2Na2O -
Reaction with Water
2Na+2H2O→2NaOH+H22Na+2H2O→2NaOH+H2 -
Reaction with Acids
Zn+2HCl→ZnCl2+H2Zn+2HCl→ZnCl2+H2
Reactivity Series
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Metals arranged in order of reactivity.
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Potassium, Sodium – highly reactive.
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Gold, Platinum – least reactive.
Extraction of Metals
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High reactivity: Electrolysis (Na, K).
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Medium reactivity: Roasting/Calcination (Zn, Fe).
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Low reactivity: Heat alone (Hg, Cu).
Chapter 4: Carbon and Its Compounds
Unique Properties of Carbon
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Catenation – Ability to form long chains.
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Tetravalency – 4 valence electrons.
Hydrocarbons
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Alkanes (CₙH₂ₙ₊₂) – Single bonds (saturated). Example: CH₄
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Alkenes (CₙH₂ₙ) – Double bond (unsaturated). Example: C₂H₄
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Alkynes (CₙH₂ₙ₋₂) – Triple bond. Example: C₂H₂
Functional Groups
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Alcohol (-OH), Carboxylic Acid (-COOH), Aldehyde (-CHO), Ketone (-CO-).
Important Reactions
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Combustion
CH4+2O2→CO2+2H2O+HeatCH4+2O2→CO2+2H2O+Heat -
Addition Reaction
C2H4+H2→C2H6C2H4+H2→C2H6 -
Substitution Reaction
CH4+Cl2→CH3Cl+HClCH4+Cl2→CH3Cl+HCl
Chapter 5: Periodic Classification of Elements
Mendeleev’s Periodic Table
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Arranged elements based on atomic mass.
Modern Periodic Table
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Arranged elements by atomic number.
Groups and Periods
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18 Groups (vertical columns).
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7 Periods (horizontal rows).
Periodic Trends
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Atomic Size – Decreases across a period, increases down a group.
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Electronegativity – Increases across a period, decreases down a group.
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Metallic Character – Decreases across a period, increases down a group.
Chapter 6: Periodic Properties (Bihar Board Special Focus)
Some Bihar Board books also highlight:
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Valency variation.
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Importance of classification.
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Predicting properties using periodic table.
Important Formulas in Chemistry
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Molecular Formula of Hydrocarbons
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Alkane: CₙH₂ₙ₊₂
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Alkene: CₙH₂ₙ
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Alkyne: CₙH₂ₙ₋₂
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pH Calculation
pH=−log[H+]pH=−log[H+] -
Molar Mass = Atomic Mass × Number of Atoms
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Faraday’s Law (Electrolysis)
Mass deposited ∝ Charge passed.
Quick Revision Points
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Always balance equations.
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Remember reactivity series (K, Na, Ca, Mg, Al, Zn, Fe, Pb, H, Cu, Ag, Au).
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Acids release H⁺, Bases release OH⁻.
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Metals are reducing agents, Non-metals are oxidizing agents.
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Carbon compounds: Covalent bonds only.
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Modern Periodic Table: Based on atomic number, not mass.
Important Objective Questions – Bihar Board Class 10 Chemistry
Q1. Which gas is evolved when zinc reacts with dilute sulphuric acid?
A) Oxygen
B) Carbon dioxide
C) Hydrogen
D) Nitrogen
Answer: Hydrogen
Q2. The reaction between acid and base is called?
A) Combination reaction
B) Displacement reaction
C) Neutralization reaction
D) Oxidation reaction
Answer: Neutralization
Q3. What is the pH value of pure water at 25°C?
A) 5
B) 6
C) 7
D) 8
Answer: 7
Q4. Which acid is present in vinegar?
A) Hydrochloric acid
B) Sulphuric acid
C) Acetic acid
D) Nitric acid
Answer: Acetic acid
Q5. Name a metal that does not react with water.
A) Sodium
B) Calcium
C) Zinc
D) Gold
Answer: Gold
Q6. What is the general formula of alkanes?
A) CₙH₂ₙ₊₂
B) CₙH₂ₙ
C) CₙH₂ₙ₋₂
D) CH₃OH
Answer: CₙH₂ₙ₊₂
Q7. Which element is called the “basis of life”?
A) Oxygen
B) Hydrogen
C) Carbon
D) Nitrogen
Answer: Carbon
Q8. Who proposed the Modern Periodic Table?
A) Mendeleev
B) Newlands
C) Moseley
D) Dalton
Answer: Moseley
Q9. Which metal is stored in kerosene oil?
A) Aluminium
B) Sodium
C) Iron
D) Copper
Answer: Sodium
Q10. Which gas turns lime water milky?
A) Oxygen
B) Carbon dioxide
C) Hydrogen
D) Ammonia
Answer: Carbon dioxide
Q11. What is the chemical formula of washing soda?
A) NaCl
B) NaOH
C) Na₂CO₃·10H₂O
D) CaCO₃
Answer: Na₂CO₃·10H₂O
Q12. What is the chemical name of bleaching powder?
A) Calcium hydroxide
B) Calcium carbonate
C) Calcium oxychloride
D) Calcium chloride
Answer: Calcium oxychloride
Q13. Which acid is called the king of chemicals?
A) HNO₃
B) H₂SO₄
C) HCl
D) CH₃COOH
Answer: H₂SO₄
Q14. The atomic number of oxygen is?
A) 6
B) 7
C) 8
D) 9
Answer: 8
Q15. Which non-metal is a good conductor of electricity?
A) Sulphur
B) Graphite
C) Phosphorus
D) Oxygen
Answer: Graphite
Q16. Which property decreases across a period in the periodic table?
A) Metallic character
B) Atomic size
C) Electronegativity
D) Valency
Answer: Atomic size
Q17. Which property increases down a group in the periodic table?
A) Non-metallic character
B) Ionization energy
C) Metallic character
D) Electronegativity
Answer: Metallic character
Q18. Which metal is used in thermometers?
A) Copper
B) Aluminium
C) Mercury
D) Lead
Answer: Mercury
Q19. The reaction 2KClO₃ → 2KCl + 3O₂ is an example of?
A) Combination reaction
B) Double displacement reaction
C) Decomposition reaction
D) Displacement reaction
Answer: Decomposition
Q20. Which functional group is present in ethanol?
A) –COOH
B) –OH
C) –CHO
D) –CO–
Answer: –OH
Conclusion
This Bihar Board Class 10 Chemistry Notes is designed for fast revision before exams. It covers all chapters, formulas, reactions, and examples in a simplified manner. If you study these notes regularly, scoring 90+ in Chemistry will become easier.