CBSE Questions for Class 11 Medical Chemistry Environmental Chemistry Quiz 7 - MCQExams.com

Carbon dioxide and carbon monoxide gases are emitted during the combustion of various fuels. Carbon monoxide is poisonous, whereas carbon-dioxide is non-toxic in nature. Carbon monoxide is poisonous because it is capable of forming a complex with hemoglobin (carboxyhaemoglobin), which is more stable than the oxygen-haemoglobin complex. The concentration range of 3–4% of  carboxyhaemoglobin decreases the oxygen-carrying capacity of blood. This results in headaches, weak eyesight, nervousness, and cardiovascular disorders. A more increased concentration may even lead to death.

Carbon monoxide when binds to hemoglobin forms a stable compound - carboxyhaemoglobin. Since, oxygen of carbon monoxide binds more readily to hemoglobin than do Oxygen of carbon dioxide, therefore carbon monoxide prevents carbon dioxide from binding to Hb, which means diffusion or exchange of gases won't take place at alveolar site. So, carbon monoxide is more harmful because it prevents oxygen from entering the body.

Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming. At the simplest level, the process of composting requires making a heap of wetted organic matter known as green waste (leaves, food waste) and waiting for the materials to break down into humus after a period of weeks or months. 

D. Ozone

When the CFC refrigerants are leaked from refrigeration or air-conditioning systems, they drift around the lower layers of the atmosphere. Slowly they start infiltrating into the upper layers of the atmosphere and soon reach the ozone rich stratosphere, where they undergo major chemical changes.

Deep injection is a liquid waste disposal technology. This alternative uses injection wells to place treated or untreated liquid waste into geologic formations that have no potential to allow migration of contaminants into potential potable water aquifers.

Other methods result into pollution and are not a feasible solution. 

The ozone layer basically absorbs harmful emissions from the sun like the ultraviolet rays, which is why life on earth is able to thrive. No other planet known to man has conditions that can favor life, and without the ozone layer, Earth would also become unable to support life. Below are some things that would happen if the ozone layer was damaged to any extent.

Cancer: one of the things that would be frequently experienced by human beings on Earth is skin cancer. Since the layer would not be able to effectively block UV rays, human skin would most likely be endangered.

Cataracts: this refers to a condition where human vision goes blurred. Almost all human beings on earth would have some sort of visual impairment without the ozone layer.

Reducing the volume and/or hazard of the waste, long-term storage or disposal, dumping at sea are ways of managing hazardous wastes. Reducing the production of waste while increasing the amount generated is a preventive method rather than a disposal method.

In situ vitrification (ISV) is a process which uses an electric current to melt soil or other earthen materials at extremely high temperatures and thereby immobilize most inorganics and destroy organic pollutants by pyrolysis. While other methods can be successfully used to dispose hazardous wastes, ISV will cause air and soil pollution.

• Due to the ozone depletion, the UV rays are filtered in the Earth's atmosphere. 
• This ray results in the development of various diseases. One of the common disorder is erythema. 
• This is a disease in which there are reddening and swelling of the skin. There is swelling of the mucous membranes. 
• There is an increase in the blood flow from the peripheral capillaries which results in inflammation.
• Thus, the correct answer is option D. 

• Chlorofluorocarbon accounts for 80% of the depletion of the ozone layer in the atmosphere. 
• CFCs contain chlorine atoms which when exposed to UV radiations from chlorine ions. 
• These chlorine ions react with the ozone molecule and remove an oxygen atom at a time and thus, breaking down ozone molecules. 
• One atom of chlorine can decompose 100,000 molecules of ozone.

$$\textbf{Correct option: A}$$

$$\textbf{Solution:}$$

Option A:

$$\bullet$$ Troposphere is the lowest layer of the atmosphere which is very close to the earth's surface.

$$\bullet$$ It has about $$75-80\%$$ of the atmospheric mass. It has all types of clouds, thus, all types of weather exist in this layer. It also has water vapors and aerosols.

$$\bullet$$ Different types of gases are present in the different compositions in this layer such as nitrogen $$78.08\%$$, oxygen $$20.95\%$$, argon $$0.93\%$$, and carbon dioxide $$0.04\%$$.

$$\bullet$$ The average thickness of the troposphere is 13 km, but at poles, the troposphere is about 8 km thick.

Hence the correct option is option A.

• The Vienna Convention for the Protection of the Ozone Layer is a multilateral environmental agreement signed in 1985.
• It provided frameworks for international reductions in the production of chlorofluorocarbons due to their contribution to the destruction of the ozone layer and the resulting increase in the threat of skin cancer.
• The Number of ozone depleters identified by Viena convention for Protection of Ozone Layer (1992) is 19.
• So, the correct answer is '19'.