Combustion and Flame in 1 Shot | Chemistry | All in One | Class 8th Complete Revision 🥳

About this Video

• Video Title: Combustion and Flame in 1 Shot | Chemistry | All in One | Class 8th Complete Revision 🥳
• Channel: PW Class 8th
• Speakers: The transcript doesn't provide a speaker's name, but it's a female instructor.
• Duration: 01:23:24

Introduction

This video provides a comprehensive one-shot revision of the Combustion and Flame chapter for 8th-grade chemistry students. The instructor covers key concepts, including types of combustion, the combustion triangle, zones of a flame, fuel types, and pollution related to combustion. The lesson incorporates interactive polls to engage students.

Key Takeaways

• Combustion: Defined as a chemical process producing heat and a new substance, requiring fuel, oxygen, and ignition temperature. The combustion triangle illustrates these three necessary components.
• Types of Combustion: Complete combustion (sufficient oxygen, producing carbon dioxide and water) and incomplete combustion (insufficient oxygen, producing carbon monoxide and water). Complete combustion produces a blue flame, while incomplete combustion produces a yellow/orange flame.
• Zones of a Flame: A candle flame has three zones: the outer (blue, hottest, complete combustion), middle (yellow, luminous, partial combustion), and inner (black, least hot, unburnt wax).
• Fuel: Any substance burned for heat; categorized as solid (wood, coal, charcoal), liquid (kerosene, petrol, diesel), or gaseous (LPG, CNG, biogas). An ideal fuel is cheap, readily available, easily combustible, has high calorific value, and produces minimal pollutants. Calorific value measures the heat energy (kJ) produced by burning 1 kg of fuel.
• Pollution from Combustion: Incomplete combustion releases harmful gases (carbon monoxide), causing respiratory problems and contributing to global warming and acid rain. CNG is presented as a cleaner alternative fuel. Fire safety measures include using fire extinguishers (creating a barrier to oxygen) and sand (for oil or electrical fires).