Chemistry - Study Mode

[#221] Of the following which one pollutes the air of a big city ?
Correct Answer

(C) Lead

[#222] Which of the following is usually not an air-pollutant?
Correct Answer

(D) Nitrous oxide

Explanation

Solution: The six air pollutants are carbon monoxide, lead, ground-level ozone, nitrogen dioxide, particulate matter, and sulfur dioxide.The combustion of gasoline and other hydrocarbon fuels in automobiles, trucks, and jet airplanes produces several primary air pollutants. Nitrous oxide (N 2 O), commonly known as laughing gas, is used in surgery and dentistry for its anaesthetic and analgesic effects.

[#223] Which of the following pollutants is main product of automobile exhaust ?
Correct Answer

(A) CO

Explanation

Solution: Cars burn fuel to run. When fuel burns completely, it mainly produces carbon dioxide (CO2). However, when the burning isn't perfect (like when a car isn't well-maintained), other things are also produced. One very important one is carbon monoxide (CO) . This is a poisonous gas. Other things found in car exhaust include nitrogen oxides (NO) and unburnt hydrocarbons. But, of the choices given, carbon monoxide (CO) is a major component of automobile exhaust , often present in higher amounts than the others due to incomplete combustion. Therefore, the correct answer is A: CO .

[#224] The smog is essentially caused by the presence of
Correct Answer

(C) Oxides of N and S

Explanation

Solution: Photochemical smog is caused by oxides of sulphur and nitrogen.

[#225] The depletion in Ozone layer is caused by ________ .
Correct Answer

(C) Chlorofluorocarbons

Explanation

Solution: Ozone depletion occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere.