Ozone & Protocols — Set 1
Environment · ओज़ोन और प्रोटोकॉल · Questions 1–10 of 50
The Kigali Amendment, which entered into force in 2019, aims to phase down the production and consumption of which substances?
Correct Answer: A. Hydrofluorocarbons (HFCs)
The Kigali Amendment specifically targets HFCs to mitigate their high global warming potential. While HFCs do not deplete ozone, they are powerful greenhouse gases. This amendment is an extension of the Montreal Protocol framework.
In which atmospheric layer is the highest concentration of the protective ozone layer found?
Correct Answer: D. Stratosphere
The stratosphere contains about 90% of the Earth's ozone, forming a protective shield. This layer is located approximately 15 to 35 kilometers above the Earth's surface. It plays a crucial role in absorbing harmful solar radiation.
Which international agreement was the first to recognize the need for global cooperation to protect the ozone layer?
Correct Answer: C. Vienna Convention
The Vienna Convention for the Protection of the Ozone Layer was adopted in 1985. It served as a framework for international efforts but did not include legally binding reduction targets. The legally binding Montreal Protocol was developed two years later.
What is the primary chemical element in CFCs that is responsible for the catalytic destruction of ozone molecules?
Correct Answer: C. Chlorine
Chlorine atoms released from CFCs react with ozone to break it down into oxygen molecules. A single chlorine atom can destroy thousands of ozone molecules over its lifetime. This process is accelerated in the presence of polar stratospheric clouds.
Which unit is standardly used to measure the total amount of ozone in a vertical column of the atmosphere?
Correct Answer: A. Dobson Unit
The Dobson Unit (DU) is the most common unit of measure for ozone thickness. One Dobson Unit represents a layer of pure ozone that would be 0.01 mm thick at standard temperature and pressure. A typical healthy ozone layer is around 300 Dobson Units.
The 'Ozone Hole' phenomenon is most prominent during which season in Antarctica?
Correct Answer: D. Spring
Ozone depletion peaks during the Antarctic spring (September to November) as sunlight returns. The returning sun triggers chemical reactions on ice clouds that release active chlorine. This leads to rapid ozone destruction within the polar vortex.
Which type of solar radiation is primarily absorbed by the ozone layer, preventing it from reaching the Earth's surface?
Correct Answer: D. UV-B radiation
The ozone layer absorbs most of the harmful UV-B radiation from the sun. Excessive UV-B reaching the surface can cause skin cancer, cataracts, and damage to marine ecosystems. It is considered the most biologically damaging part of the UV spectrum.
Which of these substances is often used as a soil fumigant and is regulated as an ozone-depleting substance?
Correct Answer: A. Methyl Bromide
Methyl Bromide is a broad-spectrum pesticide that contains bromine, which is highly effective at destroying ozone. Its use has been strictly limited under the Montreal Protocol for agricultural purposes. It is considered significantly more potent than chlorine on a per-atom basis.
What happens to a CFC molecule when it reaches the stratosphere and is exposed to intense ultraviolet radiation?
Correct Answer: C. It undergoes photodissociation
Photodissociation is the process where UV light breaks the chemical bonds of a CFC molecule. This reaction releases free chlorine atoms into the atmosphere. These free atoms then begin the chain reaction of ozone depletion.
In the troposphere, ozone is generally considered as which of the following?
Correct Answer: C. A harmful pollutant
The correct answer is 'A harmful pollutant'. While stratospheric ozone is beneficial, ground-level (tropospheric) ozone is a toxic component of smog. It is formed by reactions between nitrogen oxides and volatile organic compounds in sunlight. It can cause respiratory issues in humans and damage crops.