Question

Gases released due to the burning of fossil fuels is /are:
(This question has multiple correct options)
A) Carbon monoxide
B) Sulphur dioxide
C) Nitrogen oxide
D) Hydrocarbon

Answer 1

Hint: Combustion is a process in which fuel undergoes the chemical reaction with oxygen to produce heat. Fossil fuels are considered as the source of energy. This is composed of various elements. On combustion elements present in the fossil fuel such as carbon, sulphur, nitrogen, and hydrogen combine with oxygen and form their corresponding oxides.

Complete Solution :
- Fossil fuels are a source of energy. fossil fuels are formed by organic matters such as plants or animals which are buried in the earth's crust . This buried organic matter is converted into oil (petroleum oil), coal, and natural gas by applying high pressure and heat on the earth's crust.
- The combustion reaction of fuel is done either by absorbing energy from the environment or releasing energy into the environment . The energy causes breaking or formation of a bond.
- Coal is a fossil fuel. It is composed of carbon, hydrogen, and oxygen atoms. This typically contains carbon and hydrogen. Sometimes coal may contain a small amount of sulphur, nitrogen, or other elements. There are $\text{ C}-\text{C }$ bonds. On a burning $\text{ C}-\text{C }$ bond is broken. The combustion of coal takes place in the range of $\text{ 400 }-\text{42}{{\text{5}}^{\text{0}}}\text{C }$ . -During combustion reaction elements like carbon, sulphur hydrogen combust in presence of oxygen and liberate respective oxides. Following are the chemical reactions of combustion of fossil fuels.
- Carbon in the coal oxidizes in the presence of oxygen and combustion releases carbon dioxide gas. As follows:
$\text{ C + }{{\text{O}}_{\text{2}}}\text{ }\to \text{ C}{{\text{O}}_{\text{2}}}\text{ }$
This reaction liberates $\text{ 8084 Kcal/Kg }$ of energy per kilogram of carbon.

- Sulphur in the fossil fuel in presence of oxygen undergoes combustion and releases sulphur dioxide gas. As follows,
$\text{ S + }{{\text{O}}_{\text{2}}}\text{ }\to \text{ S}{{\text{O}}_{\text{2}}}\text{ }$
This reaction liberates $\text{ 2224 Kcal/Kg }$ of energy per kilogram of sulphur.

- Hydrogen in fossil fuel in presence of oxygen undergoes combustion reaction and releases water vapour. As follows,
$\text{ 2}{{\text{H}}_{\text{2}}}\text{ + }{{\text{O}}_{\text{2}}}\text{ }\to \text{ 2}{{\text{H}}_{\text{2}}}\text{O }$
This reaction liberates $\text{ 28922 Kcal/Kg }$ of energy per kilogram of hydrogen.

- Carbon in the fossil fuel in insufficient oxygen undergoes combustion and releases carbon monoxide gas. As follows,
$\text{ 2C + }{{\text{O}}_{\text{2}}}\text{ }\to \text{ 2CO }$
This reaction liberates $\text{ 2430 Kcal/Kg }$ of energy per kilogram of sulphur.

- Nitrogen in fossil fuels in presence of oxygen and undergoes combustion reaction and releases nitrogen dioxide gas. As follows,
$\text{ N + x}{{\text{O}}_{\text{2}}}\text{ }\to \text{ N}{{\text{O}}_{\text{x}}}$
Thus various oxides are possible,such as nitrogen oxide, nitrogen dioxide, etc.

- Natural gas also consists of methane. Thus combustion of hydrocarbon releases methane. This is a hydrocarbon. Thus combustion of fossil fuel or coal produces the following gases. these are:
$\text{ C}{{\text{O}}_{\text{2 }}}$ , $\text{ S}{{\text{O}}_{\text{2 }}}$ ,$\text{ }{{\text{H}}_{\text{2}}}\text{O (water vapour) }$, $\text{ NO}$, $\text{ C}{{\text{H}}_{\text{4}}}\text{ }$ (hydrocarbon)
So, the correct answer is “Option A, B, C and D”.

Note: Note that incomplete combustion (insufficient amount of oxygen) releases carbon monoxide gas.it is a poisonous gas. It is a strong ligand and thus readily forms a complex with a heme group of haemoglobin. This reduces the supply of oxygen to the cell and increases the feeling of suffocation. In drastic cases, it may lead to death. Carbon dioxide contributes to an increase in the earth's temperature (global warming).