A gas stove flame burns blue because of:

Correct option is D

Correct Answer: (D) Complete combustion of fuel

Explanation:

• A blue flame on a gas stove indicates that the fuel (usually natural gas or LPG) is undergoing complete combustion.
• This happens when there is a sufficient supply of oxygen for the fuel to burn efficiently. The result of complete combustion is the production of carbon dioxide (CO₂) and water vapor (H₂O), with minimal harmful emissions like carbon monoxide (CO) or soot.

Information Booster:

• Complete Combustion: When there is enough oxygen, the fuel burns at a high temperature, and the products are carbon dioxide (CO₂) and water (H₂O). This process is clean and efficient, with very low levels of pollutants.
• Blue Flame Significance:
• A blue flame indicates efficient burning, where all the carbon in the fuel is converted to carbon dioxide, and all hydrogen is converted to water vapor. It shows that the gas stove is well-adjusted and the burner is working optimally.
• It indicates that the temperature of the flame is high enough to ensure efficient combustion.
• Fuel Used: The primary fuel in gas stoves is typically methane (in natural gas) or propane (in LPG). Both these gases burn cleanly with a blue flame when they have access to the correct amount of oxygen.

Why Other Options Are Incorrect:

• A (Hazardous combustion):
• Hazardous combustion happens when there is insufficient oxygen, leading to incomplete combustion. This produces carbon monoxide (CO), soot, and a yellow or orange flame, which are indicators of inefficient combustion. The blue flame indicates that combustion is happening properly, with enough oxygen.
• B (Insufficient oxygen):
• When there is insufficient oxygen, the fuel cannot burn completely. This results in incomplete combustion, causing a yellow or orange flame and the production of harmful substances like carbon monoxide (CO) and soot. A blue flame is a sign that enough oxygen is present for complete combustion.
• C (Presence of hydrogen in the air):
• While hydrogen can burn with a pale blue flame, the main fuel used in a gas stove is natural gas (mostly methane) or propane. The blue flame is primarily due to the efficient combustion of methane or propane, not because of the hydrogen in the air.