Tag: air and air pollution

Ammonia is the simplest pnictogen hydride. N group elements are called pnictogens. And the smallest of all pnictogens is nitogen. So simplest pnictogen hydride is ammonia.

The toxicity of ammonia solutions does not usually cause problems for humans and other mammals, as a specific mechanism exists to prevent its build-up in the bloodstream. Ammonia is converted to carbamoyl phosphate by the enzyme carbamoyl phosphate synthetase, and then enters the urea cycle to be either incorporated into amino acids or excreted in the urine. Fish and amphibians lack this mechanism, as they can usually eliminate ammonia from their bodies by direct excretion. Hence ammonia even in dilute solutions is very harmful for aquatic organisms.

Ammonia is the liquid by-product of production of coke from coal.

The temperature of the troposphere generally decreases as altitude increases. The rate at which the temperature decreases is called the environmental lapse rate (ELR). 

Sulphur dioxide gas can cause acid rain in nearby places and air pollution in downwind areas from the volcanic site.

The troposphere is the lowest region of the atmosphere, i;e., closest to earth's surface. It extends roughly to a height of about 11 km. This is the region of all living organisms including, animals and plants. 

Acid rain is more properly called acidic deposition, which occurs in both wet and dry forms. Wet deposition usually exists in the form of rain, snow, or sleet but also may occur as fog, dew, or cloud water condensed on plants or the earth's surface. Dry deposition includes solid particles (aerosols) that fall to the earth's surface. Condensation of fog, dew, or cloud water is referred to as occult deposition.
The most common acidic substances are compounds containing hydrogen, sulphates, and nitrates. The chief source of these compounds is the combustion of fossil fuels such as coal, petroleum, and petroleum by-products, primarily gasoline.
Hence, acid rain is caused when air polluted by a large volume of sulphur dioxide.

Fifty percent of the total mass of the atmosphere is located in the lower $5-6$ $km$ of the troposphere. Nearly all atmospheric water vapour or moisture is found in the troposphere. So, it is the layer where most of the earth's weather takes place.

Solution:- (D) $1, \; 2$ and $3$

Acid rain is caused by a chemical reaction that begins when compounds like sulphur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain. Sulphur dioxide and nitrogen oxides dissolve very easily in water and can be carried very far by the wind. As a result, the two compounds can travel long distances where they become part of the rain, sleet, snow, and fog that we experience on certain days.
Hence, The pollutant in air responsible for acid rain is sulphur dioxide and nitrogen oxides.