Test Index

NCERT Class XII Chemistry
Chapter - The p-Block Elements
Questions with Solutions

© examsnet.com
Question : 20 of 74
Marks: +1, -0
Which aerosols deplete ozone?
Solution:  
CFC – Chlorofluorocarbon (freons) : These compounds commonlyknown as freons are introduced into the atmosphere from aerosolsprays and refrigerating equipments. They undergo photochemicaldecomposition and destroy ozone as shown by the followingsequenceofreactions.
CF2Cl2→hυ∙CF2Cl+Cl∙(free radical)\mathrm{CF_2Cl_2} \xrightarrow{h\upsilon^{\bullet}} \mathrm{CF_2Cl} + \mathrm{Cl}^{\bullet}\text{(free radical)}
CFCl3→hυ∙CFCl2+Cl∙;\mathrm{CFCl_3} \xrightarrow{h\upsilon^{\bullet}} \mathrm{CFCl_2} + \mathrm{Cl}^{\bullet};
C∙O3→ClO∙+O2\mathrm{C}^{\bullet}\mathrm{O_3} \rightarrow \mathrm{ClO}^{\bullet} + \mathrm{O_2}
ClO∙→slowCl∙+∙O;\mathrm{ClO}^{\bullet} \xrightarrow{\text{slow}} \mathrm{Cl}^{\bullet} + {}^{\bullet}\mathrm{O};
ClO∙+∙O→Cl∙+O2\mathrm{ClO}^{\bullet} + {}^{\bullet}\mathrm{O} \rightarrow \mathrm{Cl}^{\bullet} + \mathrm{O_2}
© examsnet.com
Go to Question:
Prev Question
Next Question