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Which of the following synthetic chemicals was responsible for the sharp drop in the amount of ozone in the atmosphere in the 1980s?
Iodofluorocarbons
Iodobromocarbons
Chloroiodocarbons
Chlorofluorocarbons
Chlorofluorocarbons
Chlorofluorocarbons (CFCs) were the primary synthetic chemicals responsible for the depletion of the ozone layer during the 20th century, particularly noticeable in the 1980s. These stable, non-toxic compounds were widely used in refrigeration, air conditioning, and as aerosol propellants before being phased out globally.
Chlorofluorocarbons (CFCs) were the primary synthetic chemicals responsible for the depletion of the ozone layer during the 20th century, particularly noticeable in the 1980s. These stable, non-toxic compounds were widely used in refrigeration, air conditioning, and as aerosol propellants before being phased out globally.
Think of the ozone layer as a protective umbrella for the Earth; CFCs acted like 'acid' that ate holes into the fabric of this umbrella, allowing harmful radiation to pass through.
CF2тАЛCl2тАЛ+h╬╜тЖТтЛЕCF2тАЛCl+тЛЕCl
тЛЕCl+O3тАЛтЖТтЛЕClO+O2тАЛ
When CFCs reach the stratosphere, they are broken down by ultraviolet (UV) radiation, releasing highly reactive chlorine atoms (Cl). These chlorine atoms act as a catalyst in a cyclic reaction that destroys ozone (O3тАЛ) molecules by converting them into oxygen (O2тАЛ), significantly reducing the ozone layer's ability to filter harmful UV rays.
CFCs are extremely stable in the lower atmosphere, allowing them to drift into the stratosphere.
A single chlorine atom can destroy thousands of ozone molecules before being deactivated.
The 1987 Montreal Protocol was a landmark international treaty created to phase out the production of CFCs.
Refrigerants in air conditioners
Propellants in aerosol sprays
The 'ozone hole' is not actually a hole but a significant thinning of the ozone layer, first identified in the 1980s over Antarctica.
Iodofluorocarbons, iodobromocarbons, and chloroiodocarbons are not the primary culprits associated with the 1980s ozone depletion crisis.
D is correct тАФ Chlorofluorocarbons (CFCs) were primarily responsible for the depletion of the ozone layer in the 1980s.
Always remember the Montreal Protocol when discussing ozone depletion in competitive exams; it is the most common associated topic.