NEET AIPMT SOLVED PAPER SCREENING 2004

  • question_answer
    Which of the following is responsible for depletion of the ozone layer in the upper strata of the atmosphere?

    A) Polyhalogens            

    B) Ferrocenes                

    C) Fullerenes                  

    D) Freons

    Correct Answer: D

    Solution :

    Freons or chlorofluoro carbons are responsible for depletion of the ozone layer in the upper strata of the atmosphere. They are used as propellants, aerosol spray caps, refrigerents, fire fighting reagents etc. They are stable and chemically inert compounds. They absorb UV-radiation and break down liberating free atomic chlorine which causes decomposition of ozone through free radical reaction. This results in the depletion of the ozone layer. Freons are mainly Freon-1 \[(CFC{{l}_{3}})\]andFreon-12 \[(C{{F}_{2}}C{{l}_{2}}).\]They form free radical of chlorine in presence of UV-radiation. Such free radical decomposes 03 as follows : \[C{{l}^{.}}+{{O}_{3}}\xrightarrow[{}]{{}}Cl{{O}^{.}}\,\,\,+\,\,{{O}_{2}}\] \[Cl{{O}^{.}}+{{O}_{3}}\xrightarrow[{}]{{}}\underset{\begin{smallmatrix} Chlorine\,free \\ radicaal \end{smallmatrix}}{\mathop{C{{l}^{.}}}}\,\,\,\,+\,\,2{{O}_{2}}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner