Question

The poisonous gas emitted by a motor vehicle is _____________.
(A) $\text{C}{{\text{O}}_{2}}$
(B) $\text{CO}$
(C) $\text{S}{{\text{O}}_{2}}$
(D) $\text{N}{{\text{O}}_{2}}$

Answer 1

Carbon monoxide is an odorless and tasteless gas. It is formed by the incomplete combustion of carbon containing fuels such as wood, propane, charcoal, gasoline, etc. It is also poisonous gas.

Complete answer:
Various gases are released by the motor vehicle when the fuels like petrol and diesel are not completely burnt by the vehicle’s engine thus, releasing various gases into the atmosphere. The various gases are carbon dioxide, carbon monoxide, sulphur oxide, nitrogen dioxide, etc.
CO is a poisonous gas. Carbon monoxide poisoning occurs when it is inhaled by a person or an animal. When the gas is inhaled, it comes into the contact of the blood. The carbon monoxide combines more readily with the hemoglobin than oxygen does and forms carboxyhemoglobin.

Thus, Carbon monoxide is the poisonous gas which is emitted by the motor vehicle.

Additional Information:
Properties of carbon monoxide:
-Carbon monoxide is a colorless, odorless and tasteless gas.
-Carbon monoxide is heavier than the air.
-The gas is also soluble in water which is below $70{}^\circ$.
-It is a poisonous gas which stops the supply of oxygen to the lungs.
-It is highly flammable in air and burns with a blue flame.
-It becomes liquid at $81.62\text{ K}\left( -191.53{}^\circ \text{C} \right)$ .

Note: The symptoms of carbon monoxide poisoning include headaches, weakness, dizziness, nausea, fainting, etc. In serious cases carbon monoxide causes coma, weak pulse, complete respiratory failure, and death. Carbon monoxide