In which zone is carbon monoxide burns with a blue colour at the base of the wick?

The correct answer is option 'C', the blue zone.

Explanation:
When a candle burns, it goes through different zones, each characterized by a different color and temperature. The blue zone is one of these zones, and it is where carbon monoxide burns with a blue color at the base of the wick.

To understand why carbon monoxide burns with a blue color in the blue zone, let's take a closer look at the different zones of a burning candle.

1. Ignition zone:
This is the first zone where the candle is initially lit. In this zone, the wax vaporizes and mixes with oxygen in the air. However, there is not enough heat to sustain a flame, so the candle only produces smoke and soot.

2. Luminous zone:
As the flame moves upward from the ignition zone, it enters the luminous zone. This zone is characterized by a yellow flame and is the hottest part of the flame. Here, the carbon particles from the burning wax become heated and emit light, giving the flame its yellow color.

3. Blue zone:
Above the luminous zone is the blue zone. This zone is cooler than the luminous zone and has a blue flame. In this zone, carbon monoxide, which is produced during incomplete combustion, reacts with oxygen to form carbon dioxide. This reaction produces heat and light, resulting in the blue color at the base of the wick.

4. Non-luminous zone:
The final zone is the non-luminous zone, which is the outermost part of the flame. This zone has a faint bluish hue and is the coolest part of the flame. It is in this zone that the remaining carbon particles combine with oxygen to form carbon dioxide, releasing more heat and light.

Overall, the color of a flame depends on the temperature and the chemicals present in the combustion process. The blue zone, where carbon monoxide burns with a blue color at the base of the wick, is cooler than the luminous zone and marks the transition from the hottest part of the flame to the cooler outer regions.

In conclusion, carbon monoxide burns with a blue color in the blue zone of a burning candle flame.