Tag: chemistry

Methane is a chemical compound with the chemical formula $C{ H } _{ 4 }$ (one atom of carbon and four atoms of hydrogen). It is a group 14 hydride and the simplest alkane, and is the main component of natural gas.In its natural state, methane is found both below ground and under the sea floor. When it finds its way to the surface and the atmosphere, it is known as atmospheric methane

Oxides of sulphur do not combine with any other molecule to give hydrocarbon, while manmade sources like industries, vehicles release hydrocarbon into the atmosphere.

Primary Pollutants are the ones which are injected into the atmosphere directly.  Examples include:

1. Carbon monoxide (CO)
2. Oxides of nitrogen ($N{ O } _{ x },NO$ )
3. Sulfur oxides ($S{ O } _{ x }$)
4. Volatile organic compounds (VOCs)
5. Particulate matter (dust, ash, salt particles)

Human activities have produced a 28% increase in the atmospheric concentration of carbon dioxide, from 313.83 ppm in 1960 to 400 ppm in 2015. 

Ground-level ozone is formed when volatile organic compounds (VOCs), also known as hydrocarbons, and nitrogen oxides ($N{ O } _{ x }$) interact in the presence of sunlight. Sources of VOC and $N{ O } _{ x }$ emissions include:

large industry such as chemical manufacturers, and combustion sources such as power plants burning fossil fuels.

small industry such as gasoline-dispensing facilities, auto body paint shops, and print shops

Polychlorinated biphenyls (PCB's) is the hydrocarbon pollutant from electrical transformers.

Nitrous oxide $\displaystyle N _2O$ is a greenhouse gas scientists link to global climate change. Following are the sources of nitrous oxide.
(1) Fertilizer use
(2) Fossil fuel combustion
(3) Biomass burning
(4) Changing land use

Pollutions occur due to hydrocarbons are air, water soil pollutions. Hence option D is correct.

The following are the source for hydrocarbons as pollutants:
Anaerobic bacterial decomposition of organic matter, forest fires and trees and combustion of fuels. Solvents in industrial operation.
Hence option D is correct.

The greenhouse gases absorb more of infrared rays and emits heat and this heat cannit be escaped from the atmosphere-resulting in heating up of the earth surface thereby resulting in global warming and hence greenhouse effect.