{"id":3033,"date":"2026-06-20T17:21:51","date_gmt":"2026-06-20T11:51:51","guid":{"rendered":"https:\/\/mymockmate.com\/notes\/?p=3033"},"modified":"2026-06-20T17:21:56","modified_gmt":"2026-06-20T11:51:56","slug":"ncert-class-10-science-chemical-reactions-and-equations-solutions","status":"publish","type":"post","link":"https:\/\/mymockmate.com\/notes\/ncert-class-10-science-chemical-reactions-and-equations-solutions\/","title":{"rendered":"NCERT Class 10 Science Chemical Reactions and Equations Solutions"},"content":{"rendered":"
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Short Intro<\/h1>\n\n\n\n

Chemical Reactions and Equations is the first chapter of Class 10 Science. This chapter explains chemical reactions, balancing chemical equations, types of reactions, oxidation, reduction, corrosion, and rancidity. These NCERT solutions provide step-by-step explanations for all important questions and help students prepare effectively for board examinations.<\/p>\n\n\n\n

Quick Information Box<\/h1>\n\n\n\n
Particular<\/th>Details<\/th><\/tr>
Chapter Name<\/td>Chemical Reactions and Equations<\/td><\/tr>
Class<\/td>10<\/td><\/tr>
Subject<\/td>Science<\/td><\/tr>
Board<\/td>CBSE\/State Boards<\/td><\/tr>
Important Topics<\/td>Balancing Equations, Oxidation, Reduction, Types of Reactions<\/td><\/tr>
Exam Weightage<\/td>High<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Concepts Used (Topics Covered)<\/h1>\n\n\n\n

• Chemical Reactions
• Chemical Equations
• Balanced Chemical Equations
• Combination Reactions
• Decomposition Reactions
• Displacement Reactions
• Double Displacement Reactions
• Oxidation and Reduction
• Corrosion
• Rancidity<\/p>\n\n\n\n

Important Formulas<\/h1>\n\n\n\n
    \n
  1. Law of Conservation of Mass
    Total mass of reactants = Total mass of products<\/li>\n\n\n\n
  2. Combination Reaction
    A + B → AB<\/li>\n\n\n\n
  3. Decomposition Reaction
    AB → A + B<\/li>\n\n\n\n
  4. Displacement Reaction
    A + BC → AC + B<\/li>\n\n\n\n
  5. Double Displacement Reaction
    AB + CD → AD + CB<\/li>\n<\/ol>\n\n\n\n
    \n\n\n\n

    Question 1<\/h1>\n\n\n\n

    Which statements are incorrect?<\/p>\n\n\n\n

    2PbO + C → 2Pb + CO₂<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n
    \"\"<\/figure>\n\n\n\n
    \n\n\n\n

    Question 2<\/h1>\n\n\n\n

    Fe₂O₃ + 2Al → Al₂O₃ + 2Fe<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n

    Aluminium displaces iron from iron oxide.<\/p>\n\n\n\n

    Answer<\/h3>\n\n\n\n
    Related Topic to Read more<\/span>NCERT Class 10 Maths Real Number Exercise 1.2 Solutions | MyMockMate<\/span><\/a><\/div>

    (d) Displacement Reaction<\/p>\n\n\n\n

    \n\n\n\n

    Question 3<\/h1>\n\n\n\n

    What happens when dilute hydrochloric acid is added to iron filings?<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n

    Iron reacts with HCl to form iron chloride and hydrogen gas.<\/p>\n\n\n\n

    Fe + 2HCl → FeCl₂ + H₂<\/p>\n\n\n\n

    Answer<\/h3>\n\n\n\n

    (a) Hydrogen gas and iron chloride are produced.<\/p>\n\n\n\n

    \n\n\n\n

    Question 4<\/h1>\n\n\n\n

    What is a balanced chemical equation? Why should chemical equations be balanced?<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n
    Related Topic to Read more<\/span>NCERT Class 10 Maths Exercise 2.1 Solutions | Polynomials<\/span><\/a><\/div>

    A balanced chemical equation has an equal number of atoms of each element on both sides.<\/p>\n\n\n\n

    Chemical equations are balanced because of the Law of Conservation of Mass.<\/p>\n\n\n\n

    Answer<\/h3>\n\n\n\n

    A balanced chemical equation contains equal numbers of atoms of every element on both sides. It is balanced to satisfy the law of conservation of mass.<\/p>

    \"\"<\/a><\/div><\/div>\n\n\n\n
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    Question 5<\/h1>\n\n\n\n

    Translate and balance the equations.<\/p>\n\n\n\n

    (a)<\/h3>\n\n\n\n

    Hydrogen + Nitrogen → Ammonia<\/p>\n\n\n\n

    N₂ + 3H₂ → 2NH₃<\/p>\n\n\n\n

    (b)<\/h3>\n\n\n\n
    Related Topic to Read more<\/span>Class 10 Maths Exercise 2.2 Solutions | Relationship Between Zeroes and Coefficients<\/span><\/a><\/div>

    Hydrogen sulphide + Oxygen → Water + Sulphur dioxide<\/p>\n\n\n\n

    2H₂S + 3O₂ → 2H₂O + 2SO₂<\/p>\n\n\n\n

    (c)<\/h3>\n\n\n\n

    Barium chloride + Aluminium sulphate → Aluminium chloride + Barium sulphate<\/p>\n\n\n\n

    3BaCl₂ + Al₂(SO₄)₃ → 2AlCl₃ + 3BaSO₄<\/p>\n\n\n\n

    (d)<\/h3>\n\n\n\n

    Potassium + Water → Potassium hydroxide + Hydrogen<\/p>\n\n\n\n

    2K + 2H₂O → 2KOH + H₂<\/p>\n\n\n\n

    \n\n\n\n

    Question 6<\/h1>\n\n\n\n

    Balance the following equations.<\/p>\n\n\n\n

    (a)<\/h3>\n\n\n\n

    2HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + 2H₂O<\/p>\n\n\n\n

    (b)<\/h3>\n\n\n\n

    2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O<\/p>\n\n\n\n

    (c)<\/h3>\n\n\n\n

    NaCl + AgNO₃ → AgCl + NaNO₃<\/p>\n\n\n\n

    (d)<\/h3>\n\n\n\n

    BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl<\/p>\n\n\n\n

    \n\n\n\n

    Question 7<\/h1>\n\n\n\n

    (a)<\/h3>\n\n\n\n

    Ca(OH)₂ + CO₂ → CaCO₃ + H₂O<\/p>\n\n\n\n

    (b)<\/h3>\n\n\n\n

    Zn + 2AgNO₃ → Zn(NO₃)₂ + 2Ag<\/p>\n\n\n\n

    (c)<\/h3>\n\n\n\n

    2Al + 3CuCl₂ → 2AlCl₃ + 3Cu<\/p>\n\n\n\n

    (d)<\/h3>\n\n\n\n

    BaCl₂ + K₂SO₄ → BaSO₄ + 2KCl<\/p>\n\n\n\n

    \n\n\n\n

    Question 8<\/h1>\n\n\n\n

    (a)<\/h3>\n\n\n\n

    2KBr + BaI₂ → 2KI + BaBr₂<\/p>\n\n\n\n

    Type: Double Displacement<\/p>\n\n\n\n

    (b)<\/h3>\n\n\n\n

    ZnCO₃ → ZnO + CO₂<\/p>\n\n\n\n

    Type: Decomposition<\/p>\n\n\n\n

    (c)<\/h3>\n\n\n\n

    H₂ + Cl₂ → 2HCl<\/p>\n\n\n\n

    Type: Combination<\/p>\n\n\n\n

    (d)<\/h3>\n\n\n\n

    Mg + 2HCl → MgCl₂ + H₂<\/p>\n\n\n\n

    Type: Displacement<\/p>\n\n\n\n

    \n\n\n\n

    Question 9<\/h1>\n\n\n\n

    What are exothermic and endothermic reactions?<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n

    Exothermic reactions release heat.<\/p>\n\n\n\n

    Example:
    CH₄ + 2O₂ → CO₂ + 2H₂O + Heat<\/p>\n\n\n\n

    Endothermic reactions absorb heat.<\/p>\n\n\n\n

    Example:
    CaCO₃ → CaO + CO₂<\/p>\n\n\n\n

    \n\n\n\n

    Question 10<\/h1>\n\n\n\n

    Why is respiration exothermic?<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n

    During respiration, glucose reacts with oxygen and releases energy.<\/p>\n\n\n\n

    C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy<\/p>\n\n\n\n

    Hence respiration is exothermic.<\/p>\n\n\n\n

    \n\n\n\n

    Question 11<\/h1>\n\n\n\n

    Why are decomposition reactions opposite to combination reactions?<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n

    Combination:
    A + B → AB<\/p>\n\n\n\n

    Decomposition:
    AB → A + B<\/p>\n\n\n\n

    Combination forms one product while decomposition breaks one compound into simpler substances.<\/p>\n\n\n\n

    \n\n\n\n

    Question 12<\/h1>\n\n\n\n

    Examples of decomposition reactions<\/p>\n\n\n\n

    Heat:
    CaCO₃ → CaO + CO₂<\/p>\n\n\n\n

    Light:
    2AgCl → 2Ag + Cl₂<\/p>\n\n\n\n

    Electricity:
    2H₂O → 2H₂ + O₂<\/p>\n\n\n\n

    \n\n\n\n

    Question 13<\/h1>\n\n\n\n

    Difference between displacement and double displacement reactions<\/p>\n\n\n\n

    Displacement:
    One element replaces another.<\/p>\n\n\n\n

    Zn + CuSO₄ → ZnSO₄ + Cu<\/p>\n\n\n\n

    Double displacement:
    Exchange of ions occurs.<\/p>\n\n\n\n

    Na₂SO₄ + BaCl₂ → BaSO₄ + 2NaCl<\/p>\n\n\n\n

    \n\n\n\n

    Question 14<\/h1>\n\n\n\n

    Silver recovery reaction<\/p>\n\n\n\n

    Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag<\/p>\n\n\n\n

    \n\n\n\n

    Question 15<\/h1>\n\n\n\n

    Precipitation Reaction<\/p>\n\n\n\n

    A reaction producing an insoluble solid is called a precipitation reaction.<\/p>\n\n\n\n

    Example:<\/p>\n\n\n\n

    Na₂SO₄ + BaCl₂ → BaSO₄↓ + 2NaCl<\/p>\n\n\n\n

    \n\n\n\n

    Question 16<\/h1>\n\n\n\n

    (a) Oxidation<\/h3>\n\n\n\n

    Addition of oxygen or removal of hydrogen.<\/p>\n\n\n\n

    Examples:
    2Cu + O₂ → 2CuO
    C + O₂ → CO₂<\/p>\n\n\n\n

    (b) Reduction<\/h3>\n\n\n\n

    Removal of oxygen or addition of hydrogen.<\/p>\n\n\n\n

    Examples:
    CuO + H₂ → Cu + H₂O
    ZnO + C → Zn + CO<\/p>\n\n\n\n

    \n\n\n\n

    Question 17<\/h1>\n\n\n\n

    A shiny brown element becomes black on heating.<\/p>\n\n\n\n

    Answer<\/h3>\n\n\n\n

    Element: Copper<\/p>\n\n\n\n

    Black Compound: Copper Oxide (CuO)<\/p>\n\n\n\n

    \n\n\n\n

    Question 18<\/h1>\n\n\n\n

    Why is paint applied on iron articles?<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n

    Paint prevents contact of iron with air and moisture and protects it from rusting.<\/p>\n\n\n\n

    \n\n\n\n

    Question 19<\/h1>\n\n\n\n

    Why are food items flushed with nitrogen?<\/p>\n\n\n\n

    Solution<\/h3>\n\n\n\n

    Nitrogen prevents oxidation of oils and fats and avoids rancidity.<\/p>\n\n\n\n

    \n\n\n\n

    Question 20<\/h1>\n\n\n\n

    (a) Corrosion<\/h3>\n\n\n\n

    Gradual destruction of metals by air and moisture.<\/p>\n\n\n\n

    Example:
    Rusting of iron.<\/p>\n\n\n\n

    (b) Rancidity<\/h3>\n\n\n\n

    Oxidation of fats and oils causing bad smell and taste.<\/p>\n\n\n\n

    Example:
    Spoilage of chips and fried foods.<\/p>\n\n\n\n

    Common Mistakes<\/h1>\n\n\n\n

    • Forgetting to balance equations.
    • Confusing oxidation with reduction.
    • Mixing displacement and double displacement reactions.
    • Ignoring state symbols.
    • Writing incorrect chemical formulae.<\/p>\n\n\n\n

    Exam Tips<\/h1>\n\n\n\n

    • Learn all reaction types with examples.
    • Practice balancing equations daily.
    • Remember oxidation and reduction definitions.
    • Revise important NCERT reactions.
    • Focus on board-exam frequently asked questions.<\/p>\n\n\n\n

    Practice MCQs<\/h1>\n\n\n\n
      \n
    1. Rusting of iron is an example of:
      A. Combination
      B. Corrosion
      C. Neutralization
      D. Sublimation<\/li>\n<\/ol>\n\n\n\n

      Answer: B<\/p>\n\n\n\n

        \n
      1. Which reaction releases heat?
        A. Endothermic
        B. Decomposition
        C. Exothermic
        D. Electrolysis<\/li>\n<\/ol>\n\n\n\n

        Answer: C<\/p>\n\n\n\n

          \n
        1. Whitewashing uses:
          A. CaO
          B. Ca(OH)₂
          C. CaCO₃
          D. MgO<\/li>\n<\/ol>\n\n\n\n

          Answer: B<\/p>\n\n\n\n

            \n
          1. Silver chloride decomposes in:
            A. Heat
            B. Water
            C. Sunlight
            D. Steam<\/li>\n<\/ol>\n\n\n\n

            Answer: C<\/p>\n\n\n\n

              \n
            1. Zn + CuSO₄ → ZnSO₄ + Cu is:
              A. Combination
              B. Displacement
              C. Reduction
              D. Neutralization<\/li>\n<\/ol>\n\n\n\n

              Answer: B<\/p>\n\n\n\n

              FAQ Section<\/h1>\n\n\n\n

              Q1. What is a chemical reaction?
              A. A process in which new substances are formed from reactants.<\/p>\n\n\n\n

              Q2. Why are chemical equations balanced?
              A. To satisfy the law of conservation of mass.<\/p>\n\n\n\n

              Q3. What is oxidation?
              A. Gain of oxygen or loss of hydrogen.<\/p>\n\n\n\n

              Q4. What is reduction?
              A. Loss of oxygen or gain of hydrogen.<\/p>\n\n\n\n

              Q5. What causes rusting?
              A. Reaction of iron with oxygen and moisture.<\/p>\n\n\n\n

              CTA (Call To Action)<\/h1>\n\n\n\n

              Found these NCERT Class 10 Science Chapter 1 solutions helpful? Explore more chapter-wise solutions, MCQs, notes, and previous-year questions on www.mymockmate.com<\/a> to boost your exam preparation.<\/p>\n

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