Question

While cooking, if the bottom of the vessel is getting blackened on the outside, it means that

• A. the food is not cooked completely.
• B. the fuel is not burning completely.
• C. the fuel is wet.
• D. the fuel is burning completely.

Answer 1

The correct option is B the fuel is not burning completely.

Certain substances burn partially due to limited oxygen supply and thus produce carbon monoxide and soot. While cooking, if the bottom of the vessel is getting blackened on the outside, it means that the fuel is not burning completely. ​

​When the fuel burns completely giving a blue flame, the bottom of the vessel remains clean. ​
​When the fuel does not burn completely then a sooty flame appears which makes the bottom of the utensil black.