Environmental Chemistry

Question 1

What is
environmental
chemistry?

Answer 1

The branch of chemistry which deals with the study about components of the environment and their effects on living organisms
as well as the effects of human activities on the environment

Question 2

Describe the
environmental
spheres.

Answer 2

Lithosphere: It consists of soil, rock, mud & clay. In this sphere animals and plants are found. Hydrosphere: It is consisting of
sea, ocean, rivers and pounds. In this sphere those living organism are found which can survive in water. Biosphere: In this
layer living organisms are found. It is generally known as the dry area of earth. Atmosphere: It consists of different types of
gases “Atmosphere is the envelope of different gases around the earth”

Question 3

What are the main
molecules that
compose the
Earth’s
atmosphere?

Answer 3

nitrogen (78.09%), oxygen (20.94%), argon (0.93%), carbon dioxide(0.03%), and trace amounts of other gases

Question 4

What are the four
layers of the
atmosphere and
their
characteristics?

Answer 4

Troposphere (0-12 Km, 17 °C to -58°C), Stratosphere (12-50 Km, -58°C to 2°C), Mesosphere (50-85 Km, 2°C to -93°C),
Thermosphere (85-120 Km, >-93 °C

Question 5

What are the major
constitutes of the
troposphere?

Answer 5

The major constitutes of the troposphere are nitrogen and oxygen.

Question 6

What is the range
of the
stratosphere?

Answer 6

The range of the stratosphere is 12 to 50 km.

Question 7

List the major air
pollutants.

Answer 7

The major air pollutants are methane, ozone, ammonia, and compound of fluorine.

Question 8

What are primary
pollutants?

Answer 8

Primary pollutants are the waste of exhaust products driven out because of combustion of fossil fuels and organic matter

Question 9

What are
secondary
pollutants?

Answer 9

Secondary pollutants are the produced by various reactions of primary pollutants. These are sulphuric acid, carbonic acid, nitric
acid etc.

Question 10

What are the
sources and
effects of carbon
monoxide as an air
pollutant?

Answer 10

Sources: Incomplete combustion, volcanic eruption. Effects: Extremely poisonous, contributes to dangerous ground-level air
and ozone conditions, reacts with haemoglobin, reduces transport of oxygen.

Question 11

What are the
sources and
effects of sulphur
dioxide as an air
pollutant?

Answer 11

Sources: Combustion of fossil fuels in motor vehicles, power stations and factories, industrial processes, volcanic eruptions.
Effects: Irritates the eyes and lungs, causes breathing difficulties, leads to inflammation of the lungs, reacts with water in the air
to form acid rain which corrodes buildings and harms aquatic life.

Question 12

What are the
sources and
effects of oxides of
nitrogen as air
pollutants?

Answer 12

Sources: Vehicle exhaust fumes, chemical plant and lightning activities. Effects: Increases likelihood of respiratory problems,
cancers, and other lung problems in humans, produces acid rain which is harmful to plants and animals and can lead to further
problems in water systems.

Question 13

What are the
sources of unburnt
hydrocarbon as an
air pollutant?

Answer 13

Sources: Vehicle exhaust fumes and chemical plant. Reacts with nitrogen oxides to form ozone.

Question 14

How is ozone
formed as an air
pollutant?

Answer 14

Ozone is formed by the reaction of nitrogen oxides and unburnt hydrocarbon in the presence of sunlight. It forms photochemical
smog which irritates the eyes and lungs, causing breathing problems and even damages crops.

Question 15

What causes
methane?

Answer 15

Decay of plant and animal matter.

Question 16

What is the effect of methane?

Answer 16

Greenhouse gas which causes global warming

Question 17

What are the
causes of acid
rain?

Answer 17

Natural Sources: The major natural causal agent for acid rain is volcanic emissions. Man-made sources: Human activities
leading to the primary contributors to acid rain. The activities include air pollution sources like factories, power generations
facilities, and automobiles. Use of coal for electrical power generation in industrialized areas.

Question 18

What are the
effects of acid rain
on soil?

Answer 18

Acid rain leaches heavy metals with it and discharges these metals into rivers and lakes, which can accumulate in the human
body to toxic levels and clog fish gills.

Question 19

How does acid rain
affect buildings and
monuments?

Answer 19

Acid rain attacks the calcium carbonate in marble and limestone, causing them to become dull and eroded

Question 20

What is the impact
of acid rain on soil
acidity

Answer 20

Acid rain increases the acidity of the soil, making it difficult for many crops and plants to grow properly.

Question 21

How does acid rain
directly damage
trees and plants?

Answer 21

Acid rain damages the leaves of trees and plants, limiting their growth

Question 22

How is ozone
formed in the
atmosphere

Answer 22

Ozone is formed in the atmosphere by the association of an oxygen atom with an oxygen molecule in the mid of the
stratosphere

Question 23

What are the major
sources of ozone
layer depletion?

Answer 23

CFCs are a major source of ozone layer depletion, as their compounds leak into the stratosphere and generate chlorine free
radicals that react with ozone molecules.

Question 24

What are the
effects of ozone
depletion?

Answer 24

Ozone depletion causes diseases like skin cancer, infectious diseases like malaria, and changes the life cycle of plants,
disturbing the food chain

Question 25

What are the uses
of ozone?

Answer 25

Ozone has following uses: It is used for filtration or purification of water, It is used for filtration of ultraviolet rays, It is used to
regulate earth’s temperature, It is used to protect the human being from skin problems especially from skin cancer

Question 26

What is global
warming?

Answer 26

Global warming occurs when carbon dioxide (CO 2 ), other air pollutants, greenhouse gasses collect in the atmosphere, absorb
sunlight and solar radiation that have bounced off the earth’s surface. Normally, this radiation would escape into space but
these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. That’s
what’s known as the greenhouse effect.

Question 27

What are the
effects of global
warming?

Answer 27

Melting glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages and increase the risk of
wildfire. Rising sea levels will lead to coastal flooding. Allergies, asthma, and infectious disease outbreaks will become more
common due to increased growth of pollen-producing ragweed, higher levels of air pollution, and the spread of conditions
favorable to pathogens and mosquitoes