thermal decomposition 1

 Certainly, Mayank! Here's a clear, student-friendly explanation of Activity 1.5 from the CBSE Class 10 Science textbook (Chapter 1: Chemical Reactions and Equations), ideal for class delivery, revision notes, or worksheets.

🔬 Activity 1.5 – Thermal Decomposition of Ferrous Sulphate

🧪 Aim:

To observe the thermal decomposition of ferrous sulphate crystals and identify the products formed.

🧰 Materials Required:

  • Ferrous sulphate crystals (FeSO₄·7H₂O) – about 2 g

  • Boiling tube

  • Spirit lamp or burner

  • Tongs

🔍 Procedure:

  1. Take about 2 g of ferrous sulphate crystals in a dry boiling tube.

  2. Observe and note the colour — the crystals are light green.

  3. Hold the tube with tongs and gently heat it over a flame.

  4. Observe the colour change and any smell produced.

👁️ Observations:

  • The green crystals turn brown on heating.

  • A smell of burning sulphur (like a matchstick) is noticed.

  • This indicates the release of sulphur dioxide (SO₂) gas.

🧪 Chemical Reaction:

2FeSO4(s)→HeatFe2O3(s)+SO2(g)+SO3(g)2\text{FeSO}_4 (s) \xrightarrow{\text{Heat}} \text{Fe}_2\text{O}_3 (s) + \text{SO}_2 (g) + \text{SO}_3 (g)

🧠 Explanation:

  • Ferrous sulphate crystals are hydrated salts, so they lose water first when heated.

  • Then they decompose to form:

    • Ferric oxide (Fe₂O₃) – a brown solid

    • Sulphur dioxide (SO₂) – a pungent gas

    • Sulphur trioxide (SO₃) – a gas

✅ This is a thermal decomposition reaction — one reactant breaks into multiple simpler products due to heat.

🔍 Type of Reaction:

✔ Decomposition Reaction
✔ Endothermic Process (requires heat)

💡 Conclusion:

Heating ferrous sulphate leads to a chemical change where a compound breaks down into simpler substances with the help of heat. This helps identify thermal decomposition in real time.

📘 Classroom Quick Recap Table:

Property Observation
Colour before heating Light green crystals
Change during heating Turns brown, gives off a pungent gas
Type of reaction Thermal decomposition
Products formed Fe₂O₃ (solid), SO₂ & SO₃ (gases)

🎤 Teacher's Closing Line:

“Decomposition reactions show us how one compound can split into many — just like a sentence breaking into words, each with its own identity!”

Would you like this activity included in a lab manual format, slide deck, or quiz question set for your students?

Comments

Post a Comment

Popular posts from this blog

⚡ Electrolytic Decomposition Reaction

Certainly, Mayank! Here's a Class 10–level explanation of Electrolytic Decomposition Reaction , aligned with the CBSE syllabus and written in a clear, engaging, and exam-ready format for your students. ⚡ Electrolytic Decomposition Reaction (From Chapter 1: Chemical Reactions and Equations – Class 10 Science) 🎯 Definition: An electrolytic decomposition reaction is a chemical reaction in which a compound is broken down into simpler substances using electricity . ✅ The process of using electric current to split a compound is called electrolysis . 📘 General Reaction Format: A B → Electricity A + B AB \xrightarrow{\text{Electricity}} A + B 🧪 Example: Electrolysis of Water (As shown in NCERT Activity 1.7) 2 H 2 O (l) → Electricity 2 H 2 ( g ) + O 2 ( g ) 2\text{H}_2\text{O (l)} \xrightarrow{\text{Electricity}} 2\text{H}_2 (g) + \text{O}_2 (g) Water (H₂O) splits into: Hydrogen gas (H₂) → collected at cathode Oxygen gas (O₂) → collected at anode The ...
Read more

🔥 Activity 1.11 – Oxidation and Reduction (Redox Reaction)

 Certainly, Mayank! Here's a CBSE Class 10–aligned explanation of Activity 1.11 , along with an answer to the Recall of Activity 1.1 . The focus is on conceptual clarity, oxidation-reduction (redox) concepts, and exam readiness. 🔥 Activity 1.11 – Oxidation and Reduction (Redox Reaction) (Class 10 Science – Chapter 1: Chemical Reactions and Equations) 🎯 Objective: To demonstrate how a metal (copper) undergoes oxidation and how the product can be reduced using hydrogen gas. 🧪 Materials Required: Copper powder (about 1 gram) China dish Heat source (burner or spirit lamp) Hydrogen gas (for part 2 of the reaction) 🔬 Procedure: Take a small quantity of copper powder in a china dish . Heat the copper gently. Observe any colour change. Now, pass hydrogen gas over the heated copper oxide . 👁️ Observations: Step What Happens Chemical Equation 1. Heating copper Surface turns black due to formation of copper(II) oxide (CuO) 2 Cu...
Read more

🧪 Precipitation Reaction

 Certainly, Mayank! Here's a clear, CBSE-exam–oriented explanation of the Precipitation Reaction for Class 10 Science students, with definitions, examples, and concepts aligned with the NCERT syllabus. 🧪 Precipitation Reaction (Class 10 Science – Chapter 1: Chemical Reactions and Equations) 📘 Definition: A precipitation reaction is a type of chemical reaction in which two aqueous solutions react to form an insoluble solid called a precipitate . ✅ This precipitate appears as a solid that settles at the bottom of the reaction mixture. 🔬 General Form: A B ( a q ) + C D ( a q ) → A D ( s ) ↓ + C B ( a q ) AB (aq) + CD (aq) \rightarrow AD (s) ↓ + CB (aq) AB and CD are aqueous ionic compounds AD is the precipitate (solid) CB remains dissolved in water (aqueous) 🧪 Examples from NCERT / CBSE Class 10: ✅ 1. Barium Chloride + Sodium Sulphate (Activity 1.10) BaCl 2 ( a q ) + Na 2 SO 4 ( a q ) → BaSO 4 ( s ) ↓ + 2 NaCl ( a q ) \text{BaCl}_2 (aq) + \te...
Read more