Question

Incomplete combustion of a fuel gives - - - - - - - -.
A) ${\text{CO}}$
B) ${\text{C}}{{\text{O}}_2}$
C) $S{O_2}$
D) Oxides of nitrogen

Answer 1

Hint: The incomplete combustion happens because of the insufficient supply of oxygen. When fuel is combusted in presence of insufficient oxygen it produces some undesired gases and products.

Complete step by step answer:
1) First of all let's understand the reaction of incomplete combustion. Incomplete combustion happens between an oxygen molecule and the fuel which gives the products such as carbon monoxide, carbon, and water.
2) A reaction of incomplete combustion is sometimes undesirable as the combustion produces less energy than the process of complete combustion and there is also a product formed as carbon monoxide which is a very harmful and poisonous gas.
3) Now let's see the reaction for incomplete combustion as follows,
$4C{H_4} + 5{O_2} \to 2CO + 2C + 8{H_2}O$
In the above reaction, the methane gas is burned in presence of insufficient oxygen gas which produces hazardous carbon monoxide gas, some amount of carbon, and water molecules.
4) Therefore, incomplete combustion of fuel gives the carbon monoxide gas ${\text{(CO)}}$

Hence, option A is the correct answer.

Additional information:
In ancient times humans used to apply the concept of incomplete combustion of wood for the preservation of meat and to produce smoke. When the wood is burned in presence of insufficient oxygen there is a large amount of smoke that dehydrates the whole meat piece and forms a protective layer around it that is bacterial growth resistant.

Note:
A process of incomplete combustion produces the pure form of carbon which is an undesired product and it can junk up further in the reaction equipment. The flame of incomplete combustion is an orange-colored flame.