Environmental Chemistry - Class 11 Engineering Chemistry - Extra Questions

Wastes generated by manufacturing or industrial processes are called industrial wastes. Industrial wastes include garbage, dirt and gravel, scrap metals, trash, oil, solvents, chemicals, weed grass and trees, wood and similar wastes. Industrial waste may be solid, liquid or gases. Industrial waste may be toxic, ignitable, corrosive or reactive. They can cause air pollution, water pollution and soil pollution.

Following are some of the industries which produce industrial wastes:-

• Cement Industry
• Paint Industry
  
• Leather Industry
  
• Dry clean industry

Industrial waste is the waste that is produced during manufacturing from industries, mills, mining, factories etc. Most of the agricultural waste is biodegradable and is recyclable whereas industrial waste is highly harmful to health and environment if not treated properly.

• Domestic waste is the waste generated by human dwellings. It is also called as residential waste. Sources of domestic waste includes food wastes, paper, cardboard, plastics, textiles, leather, yard wastes, wood, glass, metals, ashes, special wastes (e.g., bulky items, consumer electronics, white goods, batteries, oil, tires), and household hazardous wastes.
  
• When the concentrations of oxides of nitrogen and sulphur increases due to various reactions among the wastes, rain water gets mixed up with these oxides to form acid rains.
  

Atmosphere is created by mixture of gases and water vapours around the planet that makes it habitable. On earth, the oxygen percentage is mainly responsible for the habitable atmospherer. These factors prevent the sudden temperature and climate changes which would prevent the sudden temperature and climate changes which would have been there due to outer space effects and rotation and revolution of earth. Without them, earth would have existed but not as a life supporting planet. However, these factors have still not been found on Venus and Mars which makes them inhabitable planets for now.

Paheli and her friend observed plants will dull leaves and flowers because of the air quality present in the open area. Air is polluted on roadsides due to the emissions of harmful gases and dust particles from vehicles. These dust particles stick to the plants and make the plants dull.

Dust, smoke, mist, spray and fumes are examples of some particulate pollutants.

AQI means Air Quality Index. It is a brief, easy-to-read report of daily air quality. It tells about the level of air pollution and its effects on the health of living beings, especially humans. 

Sludge is defined as thick, soft mud or a highly viscous mixture of liquid and solid components which is obtained as a by product during industrial productions or refining processes.

The layer of air around the earth is known as atmosphere.

• The Mathura oil refinery located in Mathura, Uttar Pradesh is a refinery of IndianOil which processes low and high sulphur crude.
• It is located at a distance of 50km away from Taj Mahal.
• This oil refinery releases toxic gases such as sulphur dioxide and high levels of suspended particulate matter into the air.
• This sulphur dioxide reacts with water present in the atmosphere to form sulphuric acid. 
• This sulphuric acid formed in the atmosphere reaches the earth surface through acid rain.
• This acid is posing a great threat to Taj Mahal as it destroys the marble quality and its colour.

Acid rain refers to precipitation with a pH of less than 5. It is, in fact, a mixture of H$$_2$$SO$$_4$$ and HNO$$_3$$; the ration of two acids vary depending on the relative quantities of sulphur oxides(SO$$_2$$) and nitrogen oxides(NO$$_2$$) present in the atmosphere. These oxides are mainly produced by combustion of fossil fuels, smelters, industries, power plants, automobile exhausts, domestic fires etc. On an average, H$$_2$$SO$$_4$$ contribute 60-70% of the acidity while HNO$$_3$$ contributes 30-40%.

When fossil fuels such as coal and petroleum products are
burnt, they produce oxides of nitrogen and sulphur. On dissolving in rain these oxides of nitrogen and sulphur form nitric acid and sulphuric acid
respectively. This causes acid rain.

The gases released due to combustion of fossil fuels are $$SO_2, NO_2, CO_2$$, these gases remain suspended in the air. When it rains the rain water mixes with these gases to form sulphuric acid, nitrous acid, carbonic acid and comes down on the surface of the earth in the form of acid rain.

Harmful effects of acid rain:

1. It corrodes statues, monuments of marble, building etc.

2. It makes the soil acidic.

3. It damages crops, plantations.

Atmosphere is a layer of gases surrounding a planet or other material body, that is held in place by the gravity of that body.

Chemical pollutants (gaseous oxides such as $$\displaystyle CO_2, NO_2  \ and\ SO_2 $$) present in the atmosphere react with water to form carbonic acid, nitric acid and sulphuric acid. This causes acid rain which corrodes marble statues and monuments. The reaction between the calcium carbonate present in the monoumnets and the acid of acid rain is given below.
$$\displaystyle CO_2 + H_2O \rightarrow  CaCO_3\ or\ Ca(HCO_3)_2  $$
$$\displaystyle CaCO_3 + H_2SO_4 \rightarrow CaSO_4 + CO_2 + H_2O $$
The products are water soluble and washed away.
The presence of carbonate, sulphate and nitrate salts causes blackening of marble surfaces.

Industrial waste is the waste produced by industrial activity which includes any material that is rendered useless during a manufacturing process such as that of factories, industries, mills, and mining operations. Types of industrial waste include dirt and gravel, masonry and concrete, scrap metal, oil, solvents, chemicals, scrap lumber, even vegetable matter from restaurants. Industrial waste may be solid, liquid or gaseous. It may be hazardous or non-hazardous waste. Hazardous waste may be toxic, ignitable, corrosive, reactive, or radioactive. Industrial waste may pollute the air, the soil, or nearby water sources, eventually ending up in the sea. Industrial waste is often mixed into municipal waste, making accurate assessments difficult. 

Many small scale and bigger industrial units dump their waste which is more often toxic and hazardous, in open spaces and nearby water sources. Some industries produce a large amount of solid wastes. Solid waste contains any garbage, refuse, sludge from a wastewater treatment plant, water supply treatment plant, or air pollution control facility and other discarded materials which includes solid, liquid, semi-solid, or contained gaseous material.

Following are the industries which produce a large amount of solid waste:-

• Sugar mills
• Slaughter houses
• Paper mills
  
• Dairy plants
  
• Animal husbandry

• Industrial waste is the waste that is produced during manufacturing from industries, mills, mining, factories etc.
  
• Some examples of industrial wastes are chemical solvents, paints, sandpaper, paper products, industrial by-products, metals, and radioactive wastes.
  
• Though industrial development in India caused enormous improvement in India’s economy, it also proved disastrous to the environment.
  
• Industries caused air pollution due to the smoke released from factories.
  
• They also caused water pollution due to the draining of industrial wastes into water bodies causing hectic problems to marine and human life.
  
• Industries create high decibel noises paving a way to noise pollution creating anxiety, hypertension especially among old people and patients.
  

(i) The phenomenon of loss of water through a cut stem or injured part of the plant is called bleeding.
(ii) Pisum sativum is the scientific name of the garden pea, which Mendel used for his experiments.
(iii) A fluid that occupies the larger cavity of the eyeball behind the lens is vitreous humour.

Acid rain means the presence of excessive acids in rainwater which are formed when oxides like nitrogen dioxide and sulphur dioxide react with water.
Effects:

There are oxides in the atmosphere which can react with the water and help in the formation of the acid rain. Non-metal oxides such as sulphur dioxide and nitrogen oxide react with water. These oxides can dissolve in the water to form acid and fall on earth as acid rain.

Acid rain adversely affects the aquatic organisms and human beings. The acid rain affects the efficiency of the egg production in the aquatic animal as it breaks the shell of the fertilised eggs and death of the developing embryo. This also alters the population ratio and the gene frequency. The acid rain is responsible for skin allergies and respiratory problems in human beings.

Aim of experiment: To show that air contains nitrogen and oxygen in the ratio $$4 : 1$$ by volume.
Procedure: Take a glass container and fix a candle at its center. Put some quantity of water in the container. Place an empty, dry gas jar over it. Mark five marks above water surface on the jar at equal distances shown in the figure given below.
The candle is lightened and is covered with the gas jar. After some time the candle is extinguished and the water level is raised in gas jar. The raised level in water is $${1}/{5}$$ of the volume of air in the gas jar.
This proves that one part of the air of the jar is a gas which supports combustion, i.e., oxygen. Hence, $${1}/{5}$$ by volume is oxygen in air.

The acid rain is due to the rain water which gets mixed with the harmful gases in the atmosphere. Due to the increase in the pollution, there are harmful gases like the SO$$_2$$, NO$$_x$$ and CO$$_2$$ which mix with the water fro the rain and gets converted to poisonous acids like sulphuric acid, nitric acid and carbonic acid. This acids come down with the water in the form of acid rain. 

The components of mixture can be easily separated and they retain their properties.
The components of air are: oxygen, nitrogen, water vapour and carbon-dioxide, all these gases can be easily separated and they retain their properties.

i.A pollutant which is mainly responsible for causing acid rain - Sulphur dioxide $$(SO_2)$$
ii.Any two chemicals leading to the formation of ozone holes- Chlorofluorocarbons and Bromochlorodifluoromethane
iii.The chemical element which caused minamata disease in Japan - Mercury

Smog is dark or opaque fog which is formed by the dust and smoke articles causing condensation of water vapours around them as well as attracting chemicals like $$ SO_2, H_2S, NO_2$$ etc.

Depending upon sources waste can be classified as:

$$\bullet$$ Plants lose their ability to produce carbohydrates through photosynthesis as their leaves are de-strayed.
$$\bullet$$ Severe acid rain destroys the greenery of a region.
$$\bullet$$ The acidic nature of water causes the death and destruction of fish and corals.

Industrial areas tend to release nitrous oxides gas, or chlorine gas or sulfurous gas into the atmosphere, when these gases combine with water from the acid rain, they are turned to nitric acid ($$HNO_3$$), chloric acid ($$HCl$$) or sulfuric acid ($$H_2SO_4$$) respectively.

Smog: Oxides of nitrogen form a mixture of smoke and fog known as smog which affects our eyes too. 

• The ecological effects of acid rain are most clearly seen in aquatic environments, such as streams, lakes, and marshes where it can be harmful to fish and other wildlife.
•  As it flows through the soil, acidic rain water can leach aluminum from soil clay particles and then flow into streams and lakes.

Biodegradable pollutants

Those pollutants which can be broken down into simpler, harmless, substances in nature in due course of time (by the action of micro-organisms like certain bacteria) are called biodegradable pollutants. Domestic wastes (garbage), urine, faecal matter, sewage, agriculture residues, paper, wood, cloth, cattle dung, animal bones, leather, wool, vegetable stuff or plants are biodegradable pollutants.

Non-biodegradable pollutants

Those pollutants which cannot be broken down into simpler, harmless substances in nature, are called non-biodegradable pollutants. DDT, plastics, polythene, bags, insecticides, pesticides, mercury, lead, arsenic, metal articles like aluminum cans, synthetic fibres, glass objects, iron products and silver foils are non-biodegradable pollutants.

Mining causes soil erosion, loss of biodiversity. The chemicals released from mining activities cause contamination of soil, groundwater, surface water. Dust from mining causes air pollution. Mining activities cause noise pollution too. In this way, mining practices cause air, water, soil and noise pollution.

Column I	Column II
(i) Acid rain	Acid rain is due to the presence of $$CO_2 \,NO_2$$ and $$SO_2$$ in       air. With rain water they give carbonic acid, nitrous acid and Sulphurous acid.
(ii) Photochemical Smog	Photochemical smog is formed by unburnt fuel (hydrocarbons) and $$SO_2.$$
(iii) Combination with haemoglobin	Combination of $$CO$$ with haemoglobin gives poisonous carboxyhaemoglobin which does         not allow oxygen to bind again on it.
(iv) Depletion of ozone layer	Chlorofluorocarbon cause depletion of ozone layer by fastening the reverse process       of formation of oxygen molecule from ozone.

Those pollutants which are decomposed by bacteria like, vegetables and fruits leftovers, sewage, cow dung etc. are called biodegradable pollutants. 

Oxides of sulphur and nitrogen combine with rain water to form sulphuric acid and nitric acid which cause acid rain. 

$$atmosphere$$

Pollutant which is a combination of oxides of Nitrogen and Sulphur and partially of hydrocarbons produced by industries and automobiles. This forms a dark, thick soot laden fog know as smog.

Impacts of smog

• Smog is noxious and irritating
• Smog reduces visibility
• Smog causes respiratory problems
• Smog can cause suffocation and death.

pH of rain water is neutral in nature but when rain comes rain water combine with Carbon dioxide in the atmosphere to form carbonic acid which reduces the pH of rain water from $$ 3.5 - 5.6 $$ which sometime may reach as low as $$ 2$$.

Lead impairs our metabolic process, thereby affecting our health.

Mercuric compounds cause Minamata disease.

Smoke particles cause asthma and other respiratory diseases.

Impact on acid rain are as follows 
Acid rains make the water acidic which will affect the aquatic life adversely.

Nitrogen dioxide combines with water to form mixture of nitrous acid and nitric acid which causes acid rain.

Impact on acid rain are as follows
Acid rain causes nutrient loss and causes damage to leaves.

Impact on acid rain are as follows
Acid rain results in calcium and potassium loss from soil which affects the soil fertility.

The impact of acid rain can be reduced by checking the root cause of acid rain, i.e. bicv, reducing the emission of oxides of sulphur and nitrogen. This can be done by using coal or oil with low sulphur content. We can also reduce such emissions by using a scrubber, a device that absorbs gaseous pollutants. A scrubber used for removing sulphur dioxide from a smoke stack usually consists of a fine spray of water and gas rising from the -stack, which is passed through the scrubber, when water absorbs sulphur dioxide. Thus the formation this constituent of acid rain is reduced.

Formation of mineral acids such as carbonic acid, nitric acid, nitrous acid and Sulphuric acid and their mixture with rain is the main cause of acid rain.

Following are the methods to prevent acid rain

• By reducing the emission of Sulphur and Nitrogen oxides.
• By using a scrubber for removing sulphur dioxide from smoke.

$$ SO_2 $$ and $$ NO_2 $$ are gases responsible for acid rain.

Pollutant which is a combination of oxides of Nitrogen and Sulphur and partially of hydrocarbons produced by industries and automobiles. This forms a dark, thick soot laden fog know as smog.

Impacts of smog

• Smog is noxious and irritating
• Smog reduces visibility
• Smog causes respiratory problems
• Smog can cause suffocation and death.

Fossil fuels contain compounds of Nitrogen, Sulphur, and Carbon. A large amount of oxides of Nitrogen, Sulphur, and Carbon are discharged into the atmosphere. These oxides dissolve in rain water to form mineral acids like carbonic acid, nitric acid, and sulphuric acid. These mineral acids are the main causes of acid rain.
1) Acid rain causes nutrient loss and causes damage to leaves.
2) Acid rain results in calcium and potassium loss from the soil, which affects soil fertility.
3) Acid rains make the water acidic, which will affect the aquatic life adversely.

Smog can cause respiratory diseases and also leads to suffocation.

Composition:
Sulphur dioxide and Sulphur trioxide react with water to form $$ H_2SO_4 $$which causes acid rain.
$$ S + O_2 \rightarrow SO_2 $$ 
$$ 2 SO_2 + O_2 \rightarrow 2SO_3 $$ 

Causes:
Fossil fuels contain compounds of Nitrogen, Sulphur, and Carbon. A large amount of oxides of Nitrogen, Sulphur, and Carbon are discharged into the atmosphere. These oxides dissolve in rain water to form mineral acids like carbonic acid, nitric acid, and sulphuric acid. These mineral acids are the main causes of acid rain.

Effects:
1) Acid rain causes nutrient loss and causes damage to leaves.
2) Acid rain results in calcium and potassium loss from the soil, which affects soil fertility.
3) Acid rains make the water acidic, which will affect the aquatic life adversely.

A mixture of smoke and fog is called smog.

Oxides of nitrogen and oxides of sulphur are responsible for acid rain

Sulphur Dioxide and Nitrogen Dioxide are two gases that are responsible for acid rain.

The main components of smog are oxides of nitrogen, volatile organic compounds, tropospheric ozone and PAN (Peroxy acetyl nitrate)

Following are the two adverse effects of particular matter on human health:
(a) Asthma
(b) Respiratory tract infection

The size of particulates ranges from $$5$$ mm to $$500,000\,nm$$.

Temperature increases with altitude in stratosphere and thermosphere while it decreases in troposphere and mesosphere.

Normally rain has a pH of about $$5.6$$ due to dissolution of $$CO_2$$ of the atmosphere into it $$(CO_2 + H_2O \longrightarrow H_2CO_3 \rightleftharpoons 2H^+ + CO^{2-}_3)$$. When the pH of rain falls below $$5.6$$, it becomes acid rain.

Particulate matter consists of the solid and liquid particles suspended in air. It contains dust, pollen grains, smoke, spores, liquid droplets, etc. Many of these particulate matters are hazardous. These may cause the allergic reaction in some people. PAN (Peroxyacyl nitrate) is a respiratory irritant. It is present in the photochemical smog. Photochemical smog contains the mixture of pollutants formed after reaction of nitrogen oxides and volatile organic compounds with sunlight. Carbon dioxide is an important greenhouse gas. It traps more heat and causes global warming. Itai-itai disease results due to the cadmium poisoning. In this disease, there is severe pain in the joints and the spine. It first occurred in Japan. 

Wastes are to be managed properly if not they will have disastrous effects. Hazardous waste can cause depletion of natural resources as they are corrosive and toxic in nature. Being poisonous, they can cause serious illness to human and animal health. Some wastes have ignitability and catch fire leading to fire accidents. They undergo violent chemical reactions and produce many toxic gases polluting environment. The wastes also invite a huge number of pathogens causing many infectious diseases. They cause degradation of land, pollution of water and also affect aquatic life.

Acid rain,  that includes precipitation with acidic components, such as sulfuric or nitric acid that fall to the ground from the atmosphere in wet or dry forms. This can include rain, snow, fog, hail or even dust that is acidic.

The sulphuric acid which is a part of acid rain and is released from various industries is a common pollutant of soil. Soil which has been polluted by sulphuric acid cannot be used for cultivation of plants. 

         $$2SO_2(g) + O_2(g) + 2H_2O(l) \rightarrow 2H_2SO_4(aq)$$       $$[Sulphuric\;Acid]$$

Acid rain happens because of burning of fossil fuels which release oxides of carbon, nitrogen and sulphur in the atmosphere.

A blanket of air around earth is called $$atmosphere.$$ In absence of the atmopshere, the earth would get so cold at night that we would not be able to survive. No $$CO_2$$$ and $$N_2$$ for plants without atmosphere

Industrial waste: Industrial waste is the waste that is produced from industries during the manufacturing process. For example pieces of metals, plastic, chemicals, etc. Industrial wastes are also a major source of environmental pollution. They lead to air and water pollution. The fumes which are generated from industries are highly poisonous and directly affect the respiratory systems of animals, humans, and birds. The industrial waste materials are rich in toxic substances and heavy metals such as mercury, lead, copper, and cadmium. Mercury is a toxic substance, which exhibits the phenomenon of biomagnification when it enters the ecosystem via the food chain. Since these chemicals cannot be decomposed, they keep on accumulating at each trophic level. The maximum concentration is accumulated at the top carnivore's level. This increase in the concentration of pollutants or harmful chemicals with the increase in trophic level is called biological magnification. 

Sulphur dioxide and Sulphur trioxide react with water to form $$ H_2SO_4 $$ which causes acid rain.
 $$ S + O_2 \rightarrow SO_2 $$ 
$$ 2 SO_2 + O_2 \rightarrow 2SO_3 $$

$$\text{Layers of atmosphere}$$	$$\text{Distance from earth(approximate)}$$	$$\text{Basic function}$$
(i) Troposphere	0 to 10 kilometers	The troposphere contains most of the air and oxygen in the atmosphere. This air is fit for respiration and survival of living organisms. Weather conditions are formed in troposphere.
(ii) Stratosphere	10 to 50 kilometers	The stratosphere contains the ozone layer which prevents the harmful effects of the sun (U.V. rays) from reaching the earth.
(iii) Mesosphere	50 to 80 kilometers	The mesosphere is a very cold layer and most meteors burn up in this layer and hence are prevented from entering the earths atmosphere.

(iv) Thermosphere

80 to 320 kilometers

--

Gases such as sulphur dioxide, sulphur trioxide and nitrogen dioxide, when present in air, combine with the water droplets present in the atmosphere to form acid droplets. These droplets remain suspended in air and fall down on the earth along with rain, thereby making the rain acidic. Such rain is called acid rain. 

Acid rain: Acid rain is the rain which contains chemical present in nature and other pollutants and falls on the Earth as slightly acid solution. Rain water is slightly acid with pH level between 55
Effects of acid rain:
Acid rain represents one of the major consequences of air pollution. It may cause extensive damage to materials, terrestrial ecosystem and aquatic ecosystem. The effects of acid rain are given below:
It causes damage of buildings and structural materials made from marble, limestone etc
It causes death of aquatic animals
It causes acidification of soil which decrease the fertility of soil
It deteriorates trees, forests and field.

• Acid Rain as the name suggests can be said to be the precipitation of acid in the form of rain in the simplest manner. When atmospheric pollutants like oxides of nitrogen and sulphur react with rainwater and come down with the rain, then this results in Acid Rain.
• The causes of acid rain are Sulphur and Nitrogen particles which get mixed with the wet components of rain. Sulphur and Nitrogen particles which get mixed with water are found in two ways either man-made i.e as the emissions are given out from industries or by natural causes like how a lightning strike in the atmosphere releases nitrogen ions and sulphur is released from volcanic eruptions.
• Effects of Acid Rain

• Acid Rain as the name suggests can be said to be the precipitation of acid in the form of rain in the simplest manner. When atmospheric pollutants like oxides of nitrogen and sulphur react with rainwater and come down with the rain, then this results in Acid Rain.
• The causes of acid rain are Sulphur and Nitrogen particles which get mixed with the wet components of rain. Sulphur and Nitrogen particles which get mixed with water are found in two ways either man-made i.e as the emissions are given out from industries or by natural causes like how a lightning strike in the atmosphere releases nitrogen ions and sulphur is released from volcanic eruptions.
• Acid rain mainly contains $$H_2SO_4, HNO_3$$and trace amount of $$HCl$$ acids.
• therefore, The correct answer is $$H_2SO_4, HNO_3, HCl$$