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CBSE 3D Virtual Science LabNCERT 3D Studio
Interactive Class 10 Experiments, Real-Time Physics & 36 Apparatus Models
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Magnesium Ribbon Strip (Mg)chemistry
CBSE Exam Favourite: Magnesium ribbon is cleaned with sandpaper before burning to remove the protective oxide layer that hinders combustion.
2Mg(s) + Oโ(g) โ 2MgO(s)
ChemistryActivity 1.1 (Page 2) 1-Min Board Revision
Activity 1.1 โ Magnesium Ribbon Combustion
| Exam Parameter | Exact NCERT Board Observation & Keyword |
|---|---|
| Reactants Used | Magnesium Ribbon (Silvery-white solid, Mg) + Atmospheric Oxygen (Oโ) |
| โ Pre-Treatment | Rubbed with sandpaper to remove passivating basic MgCOโ / MgO layer |
| Burner Flame Color | Luminous Yellow-Orange Bunsen flame (~1000ยฐC) |
| โ Reaction Flame Observation | Dazzling brilliant white flame (emits intense UV glare) |
| Product Formed | White powder / ash of Magnesium Oxide (MgO) |
| Reaction Classification | Combination + Exothermic + Redox (Mg oxidized, Oโ reduced) |
| Water Dissolution | MgO (s) + HโO (l) โ Mg(OH)โ (aq) [Magnesium Hydroxide] |
| โ Litmus Test Result | Turns Red Litmus BLUE; Blue Litmus remains unaffected (Basic Nature) |
| Phenolphthalein Test | Turns colorless phenolphthalein deep PINK |
Key Scientific Inferences
- Magnesium combines with oxygen at high temperature to form an ionic basic metallic oxide.
- Metallic oxides (like MgO) are basic in nature because their aqueous solutions produce OHโป ions.
- Mass increases slightly during complete burning due to addition of oxygen atoms (Conservation of Mass).
Mandatory Lab Precautions
- Always clean the ribbon with sandpaper before ignition; otherwise, passivating oxide slows ignition.
- Hold the ribbon with crucible tongs; never hold it with bare hands due to rapid thermal conduction.
- Wear tinted safety eyeglasses / UV filter goggles to prevent retinal photochemical damage.
- Collect ash in a watch glass placed directly beneath the tilted flame to avoid hot ash spilling.
Top Examiner Traps to Avoid
- Trap: "What is the brown gas?" โ There is NO brown gas. Brown gas (NOโ) belongs to Lead Nitrate heating (Activity 1.5).
- Trap: "Does blue litmus turn red?" โ NO! Metallic oxides are basic, so RED turns BLUE, blue stays blue.
- Trap: "Why clean ribbon?" โ Answer ONLY "to remove protective passivating oxide/carbonate layer", NOT "to remove dust".
CBSE 5-Year Past Board Questions (2020โ2024)
4 QuestionsActual Class 10 board questions, marking scheme point breakdowns, and examiner trap alerts.
3 Marks
CBSE 2023 (Set 31/1/1)Observation
A student performs NCERT Activity 1.1 in the science laboratory: (a) Why should magnesium ribbon be cleaned with sandpaper before burning in air? (b) Write the chemical name and chemical formula of the product formed. (c) What is the chemical nature of this product? How would you verify it using litmus paper?
1 Mark
CBSE 2022 Term-1Observation
When a magnesium ribbon is burnt in air, the correct observation recorded by a student is: (A) Brown gas released with pop sound (B) Dazzling brilliant white flame and white powder (C) Yellow flame and black residue (D) Green flame and colourless solution
2 Marks
CBSE 2020 (Set 31/2/1)Equation
Write the balanced chemical equation with state symbols for the burning of magnesium ribbon in air. State the two reaction classifications it falls under with scientific reasons.
Featured Class 10 High-Yield 3D Practicals
๐ฅ
Chapter 1 ยท Chemistry
Activity 1.1 โ Magnesium Ribbon
Ignite the Bunsen burner, heat the sandpaper-cleaned ribbon, observe dazzling white flame emission, and trace 2-electron valence transfer creating ionic MgO powder.
๐ฏ Guaranteed 3-Mark Question2Mg + Oโ โ 2MgO
๐
Chapter 11 ยท Physics
Activity 11.2 โ Glass Prism
Trace incident, refracted, and emergent light rays through an equilateral triangular glass prism. Calculate angle of deviation (\(\delta\)) and 7-color VIBGYOR dispersion.
๐ฏ Guaranteed 5-Mark Ray DiagramA + ฮด = i + e
โค๏ธ
Chapter 5 ยท Biology
Life Processes โ Human Heart
Inspect the 4-chambered heart cross-section with pulsing lub-dub animation. Toggle pulmonary vs systemic circuits to understand double circulation and oxygen efficiency.
๐ฏ Guaranteed 5-Mark Organ Diagram4 Chambers ยท Double Loop