EVS CAT– II, Winter Semester, April 2016

SCHOOL OF ADVANCED SCIENCES

Answer Keys to CAT – II, Winter Semester, April 2016

Course Code         : CHY1002                                                                     Slot                    : A1

Class numbers      : 3378, 3381, 5491, 5492, 5493, 5494                                                        

Faculty names      : A. Anand Prabu, V. Sai Saraswathi, S.K. Ashok Kumar, K. Thirumoorthy, K.

Ravikanth, K. Santhakumar

Answer ALL the Questions (10 X 5 = 50 Marks)

1.                  Identify the hazards that the following chemicals may cause: Radon, Vinyl chloride, DDT (neurotoxins), PCBs and Bisphenol A.

Ans.:     Radiation hazards: Radon (carcinogen) (1M).

Chemical hazards: Vinyl chloride (carcinogens, teratogens), DDT and PCBs (carcinogens, teratogens, neurotoxins), Bisphenol A (hormonally active agents, which disrupt the endocrine system) (4 M).

2.                  After the occurrence of Fukushima nuclear disaster in the eastern coast of Japan 5 years ago, people in the Korean peninsula situated west of Japanese coast still avoid eating marine products like fish. Reason out.

Ans.:     Bioaccumulation effect (1 M). 

Flow chart showing the increasing levels of radiation due to bioaccumulation in marine species ultimately affecting humans consuming marine products (4 M). 

3.                  List the best five ways in which you could apply each of the three principles of sustainability to make your lifestyle more environmentally sustainable.

Ans.:     The three principles of sustainability: Reduction in use of raw materials, Reuse of waste materials and Recycling of materials (2 M). 

Any 5 best methods for each of the 3 principles that can be practiced in our daily life (3 M). For eg. Search for better efficiency fuels that are renewable, can be stored and transported and have high efficiency. Save energy in transportation- Use public transport instead of individual fuel run vehicles; Walk short distances or use bicycles, Avoid wastage: Stop lights and fans while leaving a room, Use more energy/fuel efficient devices: like energy saving bulbs, etc. 

4.                  How does a small amount of CFC gas could potentially destroy a large amount of Ozone? Which gas can actually trap CFCs and protect Ozone depletion?

Ans.:     Once released into the atmosphere, CFCs are bombarded and destroyed by ultraviolet rays.  In the process, chlorine is released which in turn destroy the ozone molecules. Single chlorine keeps on destroying Ozone for two years before it is converted to HCl or ClONO₂ (4 M including the reaction mechanism).

 The reactions are…

•          CFCl₃ + hν à CFCl₂ + Cl*

•          Cl* + O₃ à ClO + O₂

•          ClO + O₃ à Cl* +2O₂

Nitrogen oxides can trap the chlorine free radicals and stop ozone depletion (1M).

5.                  Will it be easier for a developing country like India to implement the Montreal protocol? Who is getting benefitted: a developing country like India or developed countries like USA? Justify.

Ans.:     Brief explanation about Montreal protocol (1 M). 

It’s not easy to implement this protocol by developing countries like India and China. Developed countries like USA benefit more than developing countries like India (1 M). 

Huge population, non-availability of advanced technologies, need for faster and higher rate of industrial growth results in India emitting more GHGs than that allowed in this protocol (3 M).

6.                  Identify and explain the salient features of the carbon sequestration method that could also be useful to the oil exploration industry.

Ans.: Geo-sequestration is the injection and storage of greenhouse gases underground, out of contact with the atmosphere (2 M). This method involves injecting CO₂ into an oil reservoir for enhanced recovery of oil. In the case of depleted oil wells, CO₂ can be pumped in and used as a storage reservoir (2 M). Schematic diagram (1M).

7.                  Large-scale extraction of shale oil in USA and heavy oil from oil sands in Canada has forced OPEC countries to reduce their crude oil prices in recent times. Comment on it.

Ans.:     Due to UN sanctions on Iran and civil war in Iraq in the last decade (lesser oil output) coupled with the higher industrial growth in India and China (higher demand for oil), oil prices increased to around 140$ a barrel in 2008.

The cost of extracting oil from huge shale and oil sand reserves in USA/Canada was less than the crude oil prices at that time.

Coupled with Iran’s entry to world oil market after the lifting of UN embargo in 2015, OPEC countries decided to increase their oil output which resulted in reduced crude oil prices to less than 27$ in 2016, which in turn has made the shale oil and oil sands exploration unattractive and economically unviable (Any of the above two points or even other relevant points: 3 M)

The purpose of reducing crude oil prices by OPEC countries is to suppress new investments in shale oil and oil sands exploration and ultimately to kill that competing industry (2 M)

8.         Next to your living place, the government has a proposal to start a nuclear power plant. Will you oppose or support that project? Justify with your answer.

Ans.:      Supporting nuclear energy:

Clean and cost effectiveness; Does not produce smoke or GHGs, produces huge amounts of energy from small amounts of fuel, produces small amounts of waste, nuclear power is reliable, very low accident risk, One ton of uranium produces more energy than is produced by several million tons of coal or several million barrels of oil, etc. (Overall analysis: 5 M).

Against nuclear energy:

Disposal radioactive wastes are a long-term problem and are too expensive to dispose, radiation leakage in nuclear plant lead to Chernobyl or Fukishima like accidents, exposure to nuclear radiation harms the cells of the body which can make people sick or even kill them, Illness can strike people years after their exposure to nuclear radiation, nuclear reactors only last for about forty to fifty years, high operational costs, potential for spreading nuclear weapons technology, etc. (Overall analysis: 5 M).        

9.                  What are the advantages and disadvantages of growing biomass rich plants and trees?

                 Advantages:

Wood, wood wastes, charcoal made from wood, and other forms of biomass used for heating and cooking supply 10% of the world’s energy, 35% of the energy used in less-developed countries, and 95% of the energy used in the poorest countries, etc. (2.5 M).

Disadvantages: 

Repeated cycles of growing and harvesting these plantations can deplete the soil of key nutrients, Clearing forests and grasslands for such plantations destroy or degrade biodiversity, Plantation of invasive tree species such as European poplar and American mesquite can spread from plantations to takeover nearby ecosystems, etc. (2.5 M).

10.              Toyota “Mirai” and Honda “FCX Clarity” hybrid sedan cars using hydrogen as a fuel has a selling price of Rs. ~30 lakhs in India. What are the major factors that challenge the cost reduction?

Ans.:     Lack of awareness among car buyers about the long-term and short-term cost as well as environmental benefits of investing in hybrid cars, lack of government support in terms of subsidies, tax benefits, rules and regulations for emission control, absence of local Indian manufacturers in the field of hybrid cars except Mahindra which focuses on electric car “REVA” which is an unattractive model even for an average car user in India, lack of industries focussing on R&D which lead to most of the components being imported from abroad for use in hybrid cars, etc. (Overall analysis: 5 M).

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