Combination & Decomposition Reactions | Class 10 Chemistry | CBSE Exam 2026–27

Combination & Decomposition Reactions | Class 10 Chemistry | CBSE Exam 2026–27 #chemistry COMBINATION AND DECOMPOSITION REACTIONS | CBSE CLASS 10 CHEMISTRY | SCIENCE WITH SK** Welcome to **Science With SK**! 🧪 Build confidence and win with clear, concept-based Chemistry lessons for CBSE Class 10 Science. Are you preparing for the CBSE Class 10 Science examination 2026–27? In this video, we explore two important types of chemical reactions from the chapter **Chemical Reactions and Equations**: Combination Reactions and Decomposition Reactions. This lesson is designed to help you understand definitions, identify reaction types, remember important chemical equations, and revise key examples for school examinations and board exam preparation. 📚 *WHAT WILL YOU LEARN IN THIS VIDEO?* ✅ Definition of Combination Reaction ✅ Definition of Decomposition Reaction ✅ Difference between Combination and Decomposition Reactions ✅ Thermal Decomposition (Pyrolysis) ✅ Electrolytic Decomposition (Electrolysis) ✅ Photolytic Decomposition (Photolysis) ✅ Important chemical equations ✅ Real-life applications and laboratory examples ✅ Important observations and colour changes ✅ Common examination questions and revision points ━━━━━━━━━━━━━━━━━━━━━━ 🧪 *1. COMBINATION REACTION* A combination reaction is a chemical reaction in which two or more substances combine to form a single product. *General representation:* A + B → AB *Important examples:* *Example 1: Burning of magnesium ribbon* When magnesium burns in oxygen, it forms magnesium oxide. 2Mg(s) + O₂(g) → 2MgO(s) Decomposition reactions are classified according to the energy source responsible for breaking down the compound. 🔥 *A. THERMAL DECOMPOSITION* Thermal decomposition occurs when a compound breaks down on heating. *Example 1: Decomposition of calcium carbonate* CaCO₃(s) —heat→ CaO(s) + CO₂(g) Calcium carbonate decomposes to form calcium oxide and carbon dioxide. *Example 2: Decomposition of potassium chlorate* 2KClO₃(s) —heat, MnO₂→ 2KCl(s) + 3O₂(g) Potassium chlorate decomposes on heating in the presence of manganese dioxide, which acts as a catalyst. *Example 3: Decomposition of ferrous sulphate* 2FeSO₄(s) —heat→ Fe₂O₃(s) + SO₂(g) + SO₃(g) On strong heating, ferrous sulphate decomposes to form ferric oxide, sulphur dioxide and sulphur trioxide. *Example 4: Decomposition of lead nitrate* 2Pb(NO₃)₂(s) —heat→ 2PbO(s) + 4NO₂(g) + O₂(g) Observation: Brown fumes of nitrogen dioxide are produced. 💡 *B. ELECTROLYTIC DECOMPOSITION (ELECTROLYSIS)* Electrolytic decomposition occurs when a compound breaks down due to the passage of electric current. *Example 1: Electrolysis of water* 2H₂O(l) —electricity→ 2H₂(g) + O₂(g) 📌 *WHO SHOULD WATCH THIS VIDEO?* ✔ CBSE Class 10 Science students ✔ Students revising Chemical Reactions and Equations ✔ Students practising chemical equations ✔ Learners who want clear explanations with examples ✔ Students preparing for school examinations and CBSE board exams 🚀 *SUBSCRIBE TO SCIENCE WITH SK* If this video helps you understand Chemistry better: 👍 Like the video 💬 Comment with the reaction you found most interesting 🔔 Subscribe to Science With SK for more Chemistry lessons, important reactions, scientific explanations and examination-focused revision 📤 Share this video with your classmates and friends. *Science With SK — Build Confidence and Win!* #Class10Science #CombinationReaction #DecompositionReaction #ChemicalReactionsAndEquations #CBSEChemistry #ScienceWithSK #cbse2027 combination reaction class 10, decomposition reaction class 10, combination and decomposition reactions, class 10 chemistry CBSE, chemical reactions and equations class 10, CBSE class 10 science 2026-27, combination reaction examples, decomposition reaction examples, thermal decomposition class 10, electrolytic decomposition class 10, photolytic decomposition class 10, electrolysis of water class 10, photolysis of silver chloride, silver bromide decomposition, thermal decomposition of calcium carbonate, decomposition of lead nitrate, decomposition of ferrous sulphate, potassium chlorate decomposition, burning of magnesium ribbon, magnesium oxide reaction, important chemical equations class 10, balanced chemical equations class 10, chemical reactions class 10 notes, CBSE science board exam preparation, class 10 science important questions, Science With SK #Class10Science #CBSEClass10 #CBSEChemistry #CombinationReaction #DecompositionReaction #ChemicalReactionsAndEquations #ThermalDecomposition #Electrolysis #Photolysis #ChemicalEquations #ScienceWithSK #CBSE2027 #Class10Chemistry #BoardExamPreparation #importantquestions