Which of the following conditions shows the polluted environment?
(a) pH of rain water is 5.6.
(b) Amount of carbon dioxide in the atmosphere is 0.03%.
(c) Biochemical oxygen demand is 10 ppm.
(d) Eutrophication
(c, d) Polluted water may contain nutrients for the growth of algae, which covers the water surface and reduces the oxygen concentration in water. This leads to anaerobic condition, accumulation of obnoxious decay and animal death. This is process of eutrophication.
The amount of oxygen required by bacteria to break down the organic matter present in a certain volume of sample of water is called Biochemical Oxygen Demand. Clean water would have BOD value of 5 ppm whereas highly polluted could have BOD value of 17 ppm or more.
Normally rain water has pH of 6 due to H+ ion formed by reaction of rain water with carbon dioxide in the atmosphere. When the pH of the rain water drops below 5.6, it is called acid rain.
Ozone is a toxic gas and is a strong oxidizing agent, even then its presence in the stratosphere is very important. Explain what would happen if ozone from this region is completely removed.
What would have happened if the greenhouse gases were totally missing in the earth’s atmosphere? Discuss.
Oxidation of sulphur trioxide in the absence of a catalyst is a slow process but this oxidation occurs easily in the atmosphere. Explain how does this happen. Give chemical reactions for the conversion of S02 into S03.
A person was using water supplied by Municipality. Due to shortage of water, he started using underground water. He felt laxative effect. What could be the cause?
Assertion (A): The pH of acid rain is less than 5.6.
Reason (R): Carbon dioxide present in the atmosphere dissolves in rain water and forms carbonic acid.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) Both A and R are not correct.
(d) A is not correct but R is correct.
Assertion (A): If BOD level of water in a reservoir is less than 5 ppm it is highly polluted.
Reason (R): High biological oxygen demand means low activity of bacteria in water.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) Both A and R are not correct.
(d) A is not correct but R is correct.
Assertion (A): Carbon dioxide is one of the important greenhouse gases. Reason (R): It is largely produced by respiratory function of animals and plants.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) Both A and R are not correct.
(d) A is not correct but R is correct.
Assertion (A): Excessive use of chlorinated synthetic pesticides causes soil and water pollution.
Reason (R): Such pesticides are non-biodegradable.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) Both A and R are not correct.
(d) A is not correct but R is correct.
What could be the harmful effects of improper management of industrial and domestic solid waste in a city?
Match the pollutants given in Column I with their effects given in Column II.
(a) Sulphur dioxide causes classical smog, acid rain, water pollution, induces breathing problems, causes damage to buildings, corrosion of metals.
(b) Using carbamates as pesticides can cause nerve diseases in humans
(c) Using synthetic detergents for washing clothes causes water pollution.
(d) Unsaturated hydrocarbons and nitrogen oxides produced by automobiles and factories cause photochemical smog, damage to plant life, corrosion to building material, induce breathing problems, water pollution.
(e) Chlorofluorocarbons are believed to be the main reason for ozone layer depletion.
| Column I | Column II | ||
| (a) | Phosphate fertilizers in water | (1) | BOD level of water increases |
| (b) | Methane in air | (2) | Acid rain |
| (c) | Synthetic detergents in water | (3) | Global warming |
| (d) | Nitrogen oxides in air | (4) | Eutrophication |
Assertion (A): Photochemical smog is oxidizing in nature.
Reason (R): Photochemical smog contains N02 and 03, which are formed during the sequence of reactions.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) Both A and R are not correct.
(d) A is not correct but R is correct.
During an educational trip, a student of Botany saw a beautiful lake in a , village. She collected many plants from that area. She noticed that villagers were washing clothes around the lake and at some places, waste material from houses was destroying its beauty. After few years, she visited the same r lake again. She was surprised to find that the lake was covered with algae, stinking smell was coming out and its water had become unusable. Can you explain the reason for this condition of the lake?
The pollutants which come directly in the air from source are called primary pollutants. Primary’pollutants are sometimes converted into secondary pollutants. Which of the following belongs to secondary air pollutants?
(a) CO
(b) Hydrocarbon
(c) Peroxyacetyl nitrate
(d) NO
Which of the following statements is correct?
(a) Ozone hole is a hole formed in stratosphere from which ozone oozes out.
(b) Ozone hole is a hole formed in the troposphere from which ozone oozes out. .
(c) Ozone hole is thinning of ozone layer of stratosphere at some places.
(d) Ozone hole means vanishing of ozone layer around the earth completely.
On the basis of chemical reactions involved, explain how do chlorofluoro- carbons cause thinning of ozone layer in stratosphere.
Sometime ago formation of polar stratospheric clouds was reported over Antarctica. Why were these formed? What happens when such clouds break up by warmth of sunlight?
What do you mean by green chemistry? How will it help in decreasing environmental pollution ?
Match the activity given in Column I with the type of pollution created by it given in Column II.
| Column I | Column II | |||
| Releasing gases to the atmosphere after burning waste material containing Sulphur. | 0) | Water pollution | ||
| Using carbamates as pesticides. | (2) | Photochemical smog, damage to plant life, corrosion to building material, induce breathing problems, water pollution | ||
| Using synthetic detergents for washing clothes. | (3) | Damaging ozone layer | ||
| Releasing gases produced by automobiles and factories in the atmosphere. | (4) | May cause nerve diseases in human . | ||
| Using chlorofluorocarbon compounds for cleaning computer parts. | (5) | Classical smog, acid rain, water pollution, induce breathing problems, damage to buildings, corrosion of metals | ||
For your agricultural field or garden you have developed a compost producing pit. Discuss the process in the light of bad odour, flies and recycling of wastes for a good produce.
Match the terms given in Column I with the compounds given in Column
| Column 1 | Column II | ||
| (a) | Acid rain | (1) | CHC12-CHF2 |
| (b) | Photochemical smog | (2) | CO |
| (c) | Combination with haemoglobin | (3) | co2 |
| (d) | Depletion of ozone layer | (4) | so2 |
| (5) | Unsaturated hydrocarbons | ||
Match the pollutant(s) in Column I with the effect(s) in Column II.
| Column I | Column 11 | ||
| (a) | Oxides of sulphur | (1) | Global warming . |
| (b) | Nitrogen dioxide , | (2) | Damage to kidney |
| (c) | Carbon dioxide | (3) | ‘Blue baby' syndrome |
| (d) | Nitrate in drinking water | (4) | Respiratory diseases |
| (e) | Lead | (5) | Red haze in traffic and congested areas |