SSC CGL 2023 PYQ — Question 48

The correct answer is option 4 I.e. Yellow

• The yellow color of the flame when unsaturated hydrocarbons burn is primarily due to incomplete combustion, which produces carbon particles (soot) and carbon monoxide instead of complete combustion products like carbon dioxide and water.
• The presence of incandescent soot particles and the lower flame temperature contribute to the yellow hue observed in the flame.
• This phenomenon highlights the importance of optimizing combustion conditions to ensure efficient and clean burning of hydrocarbons.
• Yellow Flame: The yellow flame is often visible when burning substances like ethene or acetylene in a non-optimal supply of oxygen. This is a practical indicator of incomplete combustion and is commonly observed in various laboratory and industrial settings.