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Class 10 SEBA Science Chapter 1 Solutions – Chemical Reactions and Equations (2026–27) | Assam Eduverse

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SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions are prepared by Assam Eduverse strictly according to the latest SEBA / ASSEB syllabus 2026–27. These SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions are created for students searching specifically for SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions that are accurate, updated, and exam-oriented. This page provides complete SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions, making it a trusted source for SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions based on the official SEBA Class 10 Science textbook.

The SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions explain all concepts included in SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions, such as types of chemical reactions, writing chemical equations, balancing chemical equations, effects of oxidation and reduction, and examples of reactions in daily life. These SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions help students understand theory, reactions, definitions, and reasoning questions using SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions written in simple and exam-friendly language, following the ASSEB Class 10 Science Chapter 1 solutions format.

With the complete SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions (2026–27), students can prepare SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions for intext questions and SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions for chapter-end textbook exercise questions. These SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solutions include important question answers and exam-focused explanations. Assam Eduverse ensures every SEBA Class 10 Science Chapter 1 Chemical Reactions and Equations solution is syllabus-based and exam-focused.

SEBA / ASSEB Class 10 Science Chapter 1 – Chemical Reactions and Equations Intext Questions & Answers (Latest Syllabus 2026–27)

📝 Page 6 

Q1. Why should a magnesium ribbon be cleaned before burning in air?

Answer: Magnesium gets covered with a layer of magnesium oxide when exposed to air for long periods. This layer prevents the magnesium from burning efficiently. Hence, it must be cleaned before burning.

Q2. Write the balanced equation for the following chemical reactions.
(i) Hydrogen + Chlorine → Hydrogen chloride
(ii) Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride
(iii) Sodium + Water → Sodium hydroxide + Hydrogen

Answer:
(i) H2 + Cl2 → 2HCl
(ii) 3BaCl2 + Al2(SO4)3 → 3BaSO4 + 2AlCl3
(iii) 2Na + 2H2O → 2NaOH + H2

Q3. Why is it important to balance a chemical equation?

Answer: A balanced chemical equation ensures the law of conservation of mass is followed. The number of atoms for each element remains the same on both sides of the reaction. It also helps in determining correct quantities of reactants and products involved.

📝 Page 10

Q1. Write a balanced chemical equation with state symbols for the following reaction:
Barium chloride solution reacts with sodium sulphate solution to give insoluble barium sulphate and sodium chloride solution.

Answer:
BaCl2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaCl (aq)

This is a double displacement reaction and a precipitation reaction since BaSO4 is insoluble.

Q2. Why is the amount of gas collected in one of the test tubes in Activity 1.7 (Electrolysis of Water) double the amount collected in the other? Name the gas.

Answer: Water decomposes into hydrogen and oxygen in the ratio 2:1. The chemical equation is:
2H2O → 2H2 + O2
This means the amount of hydrogen gas collected is double that of oxygen.

📝 Page 13 

Q1. Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

Answer: Iron is more reactive than copper and displaces copper from copper sulphate solution. This forms greenish iron sulphate and brown copper metal gets deposited.
Equation: Fe + CuSO4 → FeSO4 + Cu

Q2. Give an example of a double displacement reaction other than the one given in the book.

Answer: Na2CO3 + CaCl2 → CaCO3 + 2NaCl
Here, two compounds exchange ions and a white precipitate of calcium carbonate forms.

Q3. Identify the substances oxidised and reduced in the following reactions:
(i) 4Na + O2 → 2Na2O
(ii) CuO + H2 → Cu + H2O

Answer:
(i) Sodium (Na) is oxidised; Oxygen (O2) is reduced.
(ii) Hydrogen (H2) is oxidised; Copper oxide (CuO) is reduced.

SEBA Class 10 Science Chapter 1 – Chemical Reactions and Equations Textbook Exercise Questions & Solutions | 2026–27

Q1.  Which of the statements about the reaction below are incorrect?

2PbO(s) + C(s) → 2Pb(s) + CO2(g)

  • (a) Lead is getting reduced.
  • (b) Carbon dioxide is getting oxidised.
  • (c) Carbon is getting oxidised.
  • (d) Lead oxide is getting reduced.

Correct Answer: (i) (a) and (b)

Explanation: Lead is actually getting reduced and carbon is getting oxidised. So, statement (a) is correct, but (b) is incorrect because CO2 is not getting oxidised, it is a product of oxidation.

Q2. Fe2O3 + 2Al → Al2O3 + 2Fe

The above reaction is an example of a:

Correct Answer: (d) displacement reaction

Explanation: Aluminium displaces iron from its oxide, hence it is a displacement reaction.

Q3 What happens when dilute hydrochloric acid is added to iron fillings?

Correct Answer: (a) Hydrogen gas and iron chloride are produced.

Reaction: Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g)

Q4. What is a balanced chemical equation? Why should chemical equations be balanced?

Answer: A balanced chemical equation has equal numbers of atoms of each element on both sides of the equation. It should be balanced to obey the Law of Conservation of Mass, which states that matter can neither be created nor destroyed in a chemical reaction.

Q5.Translate the following statements into chemical equations and then balance them.

  • (a) N2 + 3H2 → 2NH3
  • (b) 2H2S + 3O2 → 2H2O + 2SO2
  • (c) 3BaCl2 + Al2(SO4)3 → 2AlCl3 + 3BaSO4
  • (d) 2K + 2H2O → 2KOH + H2

Q6. Balance the following chemical equations.

  • (a) 2HNO3 + Ca(OH)2 → Ca(NO3)2 + 2H2O
  • (b) 2NaOH + H2SO4 → Na2SO4 + 2H2O
  • (c) NaCl + AgNO3 → AgCl + NaNO3
  • (d) BaCl2 + H2SO4 → BaSO4 + 2HCl

Q7. Write the balanced chemical equations for the following reactions.

  • (a) Ca(OH)2 + CO2 → CaCO3 + H2O
  • (b) Zn + 2AgNO3 → Zn(NO3)2 + 2Ag
  • (c) 2Al + 3CuCl2 → 2AlCl3 + 3Cu
  • (d) BaCl2 + K2SO4 → BaSO4 + 2KCl

Q8. Write the balanced chemical equation for the following and identify the type of reaction in each case.

  • (a) 2KBr(aq) + BaI2(aq) → 2KI(aq) + BaBr2(s) [Double displacement reaction]
  • (b) ZnCO3(s) → ZnO(s) + CO2(g) [Decomposition reaction]
  • (c) H2(g) + Cl2(g) → 2HCl(g) [Combination reaction]
  • (d) Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) [Displacement reaction]

Q9. What does one mean by exothermic and endothermic reactions? Give examples.

Answer: Exothermic reactions release heat. For example: C(s) + O2(g) → CO2(g) + heat. Endothermic reactions absorb heat. For example: Ba(OH)2 + NH4Cl → BaCl2 + NH3 + H2O (absorbs heat).

Q10. Why is respiration considered an exothermic reaction? Explain.

Answer: Respiration is the process by which glucose (C6H12O6) is broken down in the presence of oxygen to release energy. The reaction is:

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy

This reaction releases heat, hence it is exothermic.

Q11. Why are decomposition reactions called the opposite of combination reactions? Write equations.

Answer: In decomposition reactions, a compound breaks down into simpler substances. In contrast, in combination reactions, simpler substances combine to form a compound.
Combination: 2H2 + O2 → 2H2O
Decomposition: 2H2O → 2H2 + O2

Q12. Write one equation each for decomposition reactions using (a) heat, (b) light, (c) electricity.

Answer:
(a) CaCO3 → CaO + CO2 (heat)
(b) 2AgCl → 2Ag + Cl2 (light)
(c) 2H2O → 2H2 + O2 (electricity)

Q13. What is the difference between displacement and double displacement reactions? Write equations.

Answer:
Displacement: One element replaces another in a compound. E.g., Zn + CuSO4 → ZnSO4 + Cu
Double Displacement: Two compounds exchange ions. E.g., AgNO3 + NaCl → AgCl + NaNO3

Q14. In the refining of silver, the recovery of silver from AgNO3 is done by displacement with copper. Write the equation.

Answer: Cu + 2AgNO3 → Cu(NO3)2 + 2Ag

Q15. What do you mean by precipitation reaction? Give one example.

Answer: A precipitation reaction results in the formation of an insoluble product. E.g., BaCl2 + Na2SO4 → BaSO4↓ + 2NaCl

Q16. Explain oxidation and reduction with examples.

Answer:
Oxidation: Gain of oxygen or loss of hydrogen. E.g., C + O2 → CO2
Reduction: Gain of hydrogen or loss of oxygen. E.g., CuO + H2 → Cu + H2O

Q17. A shiny brown substance on heating in air becomes black. Name the substance and black product.

Answer: Shiny brown substance: Copper (Cu), Black product: Copper oxide (CuO)
Reaction: 2Cu + O2 → 2CuO

Q18. Why do oil and fat-containing food items become rancid?

Answer: They react with oxygen and undergo oxidation, developing unpleasant smell and taste. This process is called rancidity.

Q19. Explain the use of antioxidants in food.

Answer: Antioxidants prevent oxidation, thereby protecting food from becoming rancid. Common antioxidants include BHA and BHT used in snacks.

Q20. What is the significance of a balanced chemical equation?

Answer: It ensures the law of conservation of mass is followed and helps in correct calculation of reactants and products involved in the reaction.

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