HSC Board Exams are fast approaching and students are getting anxious about how to prepare for their HSC Board Exams. This question paper exclusively designed for the chapter Environmental Chemistry from plus one Chemistry. The latest sample papers have been designed as per the latest syllabus and examination trends.

Now you can use this model question paper for practice on your own to score more on your board exams. By practicing with this important model question paper student can gain more knowledge and confidence to crack the exams. Our aim is to bring out the best scores on board exams. Creative questions were added in this question paper in order to enhance the student's knowledge and get the idea that how to answer strategic questions asked in the board exams.

By practicing repeatedly you will get the idea of answering the questions and this improves the speed of answering. This will save the time and you can complete all the questions without any last our tension. Get more model question papers and practice for the board examination.

It's the right time to grab the model question papers on chapter wise and practice for the board exams. This question paper is designed based on the academic syllabus. It will be more helpful for the Matriculation and state board students to prepare for their exams. The best way to prepare exams is to simply do one thing at a time. Using the model question papers, every student can get an idea about the exam questions in a subject wise and collect more information to score high marks on all exams

Download Tamil Nadu 11th Standard Chemistry question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.

Questions:

Multiple Choice Question

4 x 1 = 4

Green house gases cause _____________

(a)

Increase in temperature of atmosphere

(b)

Prevents global warming

(c)

Trap UV rays

(d)

All the above

High concentration of lead in human blood damages ______________

(a)

Brain

(b)

Liver

(c)

Both (a) & (b)

(d)

Neither (a) nor (b)

Biochemical oxygen Demand value less than 5 ppm indicates a water sample to be ______.

(a)

highly polluted

(b)

poor in dissolved oxygen

(c)

rich in dissolved oxygen

(d)

low COD

Which sequence for green house gases is based on GWP ?

(a)

CFC > N₂O > CO₂ > CH₄

(b)

CFC > CO₂> N₂O > CH₄

(c)

CFC > N₂O > CH₄ > CO₂

(d)

CFC > CH₄ > N₂O > CO₂

Assertion and reason

1 x 2 = 2

Assertion (A) : If BOD level of water in a reservoir is more than 5 ppm it is highly polluted
Reason(R) : High biological oxygen demand means high activity of bacteria in water
i) Both (A) and R are correct and (R) is the correct explanation of (A)
ii) Both (A) and R are correct and (R) is not the correct explanation of (A)
iii) Both (A) and R are not correct
iv) (A) is correct but( R) is not correct

(a)

Both (A) and R are correct and (R) is the correct explanation of (A)

(b)

Both (A) and R are correct and (R) is not the correct explanation of (A)

(c)

Both (A) and R are not correct

(d)

(A) is correct but( R) is not correct

Generic 3

5 x 3 = 15

Write the impact of depletion of ozone layer on plants, human and aquatic life.

Discuss the harmful effects of improper waste management in the city

Bring out the differences between classical and photochemical smog

A person was using water supplied by corporation. Due to shortage of water he started using underground water. He felt laxative effect. What could be the cause ?

10.

What would happen, if the greenhouse gases were totally missing in the earth’s atmosphere ?

Generic 2

5 x 2 = 10

11.

Name any four methods of waste management

12.

Write a short note on global warming.

13.

How does classical smog differ from photochemical smog ?

14.

From where does ozone come in the photo chemical smog ?

15.

Which is considered to be earth’s protective umbrella ? Why ?

Generic 5

4 x 5 = 20

16.

What is water pollution ? Give a detailed account on causes and harmful effects of water pollution.

17.

(i) How does pollutants vary from contaminants?
(ii) Classify the pollutants on the following basis & give examples.
Depending on their physical state
Depending upon their degradability.
Depending on their formation and existence in nature.

18.

Explain how oxygen deficiency is caused by carbon monoxide in our blood ? Give its effect

19.

How is acid rain formed ? Explain its effect

Visit QB365-SLMS - https://www.qb365.in/slms/

Answers Key:

Multiple Choice Question

4 x 1 = 4

(a)
Increase in temperature of atmosphere

Assertion and reason

1 x 2 = 2

iv) (A) is correct but( R) is not correct

Generic 3

5 x 3 = 15

(i) Impact on human:
Exposure to UV radiation lead to ageing of skin, cataract, sun bum and skin cancer.
(ii) Impact on aquatic life:
Many phytoplanktons are killed and the productivity of fishes are damaged.
(iii) Impact on plant life:
The plant proteins get easily affected by UV radiation.
It also increases evaporation of surface water through the stomata of the leaves and decrease the moisture content of the soil.

(i) If the domestic waste is not managed properly. it might move down into severs or may be eaten up by the cattle.
(ii) The non-biodegradable waste like polythene bags, metal scraps. etc obstruct the servers.
(iii) The improper management of industrial waste will cause air, soil and water pollution

CLASSICAL SMOG	PHOTO CHEMICAL SMOG
(i) Classical smog was first observed in London in December 1952 and hence it is also known as London smog.	Photo Chemical smog was first observed in Los Angels in 1950. It occurs in warm, dry and sunny climate.
(ii) It consists of coal smoke and fog.	This type of smog is formed by the combination of smoke, dust and fog with air pollutants like oxides of nitrogen and hydrocarbons in the presence of sunlight.
(iii) It occurs in cool humid climate. This atmospheric smog found in many large cities. The chemical composition is the mixture of SO₂, SO₃ and humidity. It generally occurs in the morning and becomes worse when the sun rises	It forms when the sun shines and becomes worse in the afternoon.
(iv) Chemically it is reducing in nature because of high concentration of SO₂ and so it is also called as reducing smog.	Chemically it is oxidizing in nature because of high concentration of oxidizing agents NO2 and O3, so it is also called as oxidizing smog.
(v) It causes bronchial irritation.	It causes irritation to eyes, skin and lungs throat infection, chest pain and difficulty in breathing.

There may be exercise concentration ( > 500 ppm) of sulphates in the ground water. So he could have felt laxative effect.

10.

Without the heating caused by the greenhouse effect, earth's average surface temperature would be only about -18 ^oC (0 ^oF). Although the greenhouse effect is a naturally occurring phenomenon, it is intensified by the continuous emission of greenhouse gases into the atmosphere.
During the past 100 years, the amount of carbon dioxide in the atmosphere increased by roughly 30 percent and the amount of methane more than doubled.If these trends continue, the average global temperature will increase which can lead to melting of polar ice caps and flooding of low areas. This will increase incidence of infectious diseases like dengu., malaria, etc.

Generic 2

5 x 2 = 10

11.

(i) Recycling
(ii) Burning and incineration
(iii) Sewage Treatment
(iv) Dumping

12.

The heating up of earth through the greenhouse effect is called global warming. Although the greenhouse effect is a naturally occurring phenomenon, it is intensified by the continuous emission of greenhouse gases into the atmosphere. During the past 100 years, the amount of carbon dioxide in the atmosphere increased by roughly 30 percent and the amount of methane more than doubled. If these trends continue, the average global temperature will increase which can lead to melting of polar ice caps and flooding of low lying areas. This will increase incidence of infectious diseases like dengue, malaria, etc

13.

S.No	Classical somg (london smog)	Photochemical smog (Los Angels smog)
1	It was first observed in London in Dec. 1952	It was first observed in Los Angels in 1950.
2	It occurs in cool, humid climate	It occurs in warm, dry and sunn climate
3	It consists of coal smoke and fog	It is formed by the combination of smoke dust and fog with air pollutants like N₂ and hydrocarbons in presence of light.
4	It generally occurs in the morning and becomes worse when the sunshines	It forms when the sunshines and becomes worse in the afternoon.
5	This is mainly due to the induced oxidation of SO₂ to SO₃, which reacts with water yielding sulphuric acid aerosol.	This is mainly due to the induced oxidation of N₂ to NO, NO₂ and [O] + O₂ to O₃NO and O₃ are strong oxidising agents and can react with unburnt hydrocarbons in polluted air to form HCHO, Acrolein and PAN.
6	Chemically it is reducing in nature because of high concentration of SO₂.	Chemically it is oxidising in nature because of high concentrations of oxidising agents like NO₂ and O₂
7	It is called reducing smog	It is called oxidising smog
8	Responsible for acid rain, causes poor visibility, affects air and road transport and causes bronchial irritation.	Causes irritation to nose, throat, eyes, skin and lungs, increases asthma, causes chest pain, uncomfortable breathing, PAN attacks young leaves, causes corrosion of metals, stones painted surfaces, etc.,

14.

Ozone is formed by a series of reactions that occur from the sun shines

15.

At high altitudes to the atmosphere consists of a layer of ozone (O₃) which acts as an umbrella or shield for harmful UV radiations. It protects us from harmful effect such as skin cancer. UV radiation can convert molecular oxygen into ozone as shown in the following reaction.

Ozone gas is thermodynamically unstable and readily decomposes to molecular oxygen.

Generic 5

4 x 5 = 20

16.

Water pollution is defined as "The addition of foreign substances or factors like heat which degrades the quality of water, so that it becomes health hazard or unfit to use."
(i) The water pollutants originate from both natural and human activities. The source of water pollution is classified as Point and Non-point source.
(ii) Easily identified source of place of pollution is called as point source.
Example: municipal and industrial discharge pipes.
(iii) Non-point source cannot be identified easily.
Example: agricultural runoff, mining wastes, acid rain, and storm-water drainage and construction sediments.

POLLUTANT	SOURCES
(i) Micro-organisms	Domestic sewage, domestic waste water, dung heap
(ii) Organic wastes	Domestic sewage, animal excreta, food processing factory waste, detergents and decayed animals and plants.
(iii) Plant nutrients	Chemical fertilisers
(iv) Heavy metals	Heavy metal producing factories
(v) Sediments	Soil erosion by agriculture and strip-mining.
(vi) Pesticides	Chemicals used for killing insects, fungi and weeds.
(vii) Radioactive substances	Mining of uranium containing minerals.
(viii) Heat	Water used for cooling in industries.

(a) Causes of water pollution:
(i) Microbiological (Pathogens) : Disease causing microorganisms like bacteria, viruses and protozoa are most serious water pollutants. They come from domestic sewage and animal excreta. Fish and shellfish can become contaminated and people who eat them can become ill. Some serious diseases like polio and cholera are water borne diseases. Human excreta contain bacteria such as Escherichia coli and Streptococcus faecalis which cause gastrointestinal diseases.
(ii) Organic wastes: Organic matter such as leaves, grass, trash etc can also pollute water. Water pollution is caused by excessive phytoplankton growth within water. Microorganisms present .in water decompose these organic matter and consume dissolved oxygen in water.
(iii) Eutrophication: Eutrophication is a process by which water bodies receive excess nutrients that stimulates excessive plant growth ( algae, other plant weeds).This enhanced plant growth in water bodies is called as algae bloom. The growth of algae in extreme abundance covers the water surface and reduces the oxygen concentration in water. Thus, bloom-infested
(b) Biochemical oxygen demand(BOD):
(i) The total amount of oxygen in milligrams consumed by microorganisms in decomposing the waste in one litre of water at 200C for a period of 5 days is called biochemical oxygen demand (BOD) and its value is expressed in ppm.
(ii) BOD is used as a measure of degree of water pollution. Clean water would have BOD value less than 5 ppm whereas highly polluted water has BOD value of 17 ppm or more
(c) Chemical wastes:
(i) A whole variety of chemicals from industries, such as metals and solvents are poisonous to fish and other aquatic life
(ii) Some toxic pesticides can accumulate in fish and shell fish and poison the people who eat them. Detergents and oils float and spoil the water bodies. Acids from mine drainage and salts from various sources can also contaminate water sources.
Harmful effcts of chemical water pollutants:
(i) Cadmium and mercury can cause kidney damage.
(ii) Lead poisoning can leads to the severe damage of kidneys, liver, brain etc. it also affects central nervous system
(iii) Polychlorinated biphenyls (PCBs) causes skin diseases and are carcinogenic in nature.

17.

Pollutants	Contaminants
A substance which causes pollution are called pollutants. Eg: Fertilizers	The pollutants that do not occur in nature and are introduced into the environment by human activity are called contaminants. Eg: pyrosulphuric acid (H₂S₂O₇).

18.

It binds with haemoglobin and form carboxy haemoglobin which impairs normal oxygen transport by blood and hence the oxygen carrying capacity of blood is reduced. This oxygen deficiency results in headache, dizziness, tension, Loss of consciousness, blurring of eye sight and cardiac arrest.

19.

Rain water normally has a pH of 5.6 due to dissolution of atmospheric CO₂ into it. Oxides of sulphur and nitrogen in the atmosphere may be absorbed by droplets of frater that make up clouds and get chemically converted into sulphuric acid and nitric acid respectively as a results of pH of rain water drops below the level 5.6, hence it is called acid rain. Acid rain is a by-product of a variety of sulphur and nitrogen oxides in the atmosphere. Burning of fossil fuels (coal and oil) in power stations, furnaces and petrol, diesel in motor engines produce sulphur dioxide and nitrogen oxides The main contributors of acid rain are SO₂ and NO₂.They are converted into sulphuric acid and nitric acid respectively by the reaction with oxygen and water.
2SO₂ + O₂ + 2H₂O ⟶ 2H₂SO₄
4NO₂ + O₂ + 2H₂O ⟶ 4HNO₃
Harmful effects of acid rain
Some harmful effects are discussed below :
(i) Acid rain causes extensive damage to buildings and structural materials of marbles. This attack on marble is termed as Stone leprosy.
CaCO₃ + H₂SO₄ ⟶ CaSO₄ + H₂O +CO₂ ↑
(ii) Acid rain affects plants and animal life in aquatic ecosystem.
(iii) It is harmful for agriculture, trees and plants as it dissolves and removes the nutrients needed for their growth.
(iv) It corrodes water pipes resulting in the leaching of heavy metals such as iron, lead and copper into the drinking water which have toxic effects.
(v) It causes respiratory ailment in humans and animals.