CBSE Class 11-science Answered
how is cfc responsible for depletion of ozone layer?
Asked by Badrinath Mishra | 09 Feb, 2013, 10:42: PM
Expert Answer
Ozone in the lower atmosphere is formed during electrical discharge from high voltage appliances as shown in the equations below:
O2(g) -----> 2O(g)
O2(g) + O(g) -----> O3(g)
CFCs destroy the ozone in the stratosphere (15 - 20 km above the earth's surface)
(Ozone concentrations are measure in Dobsen units, 1 Dobsen unit represents 1 molecule of O3 for every 1 billion air molecules)
Ozone loss is greatest over Antarctica where the ozone depletion has been recorded and is commonly referred to as the "ozone hole".
(Ozone concentrations are measure in Dobsen units, 1 Dobsen unit represents 1 molecule of O3 for every 1 billion air molecules)
Ozone loss is greatest over Antarctica where the ozone depletion has been recorded and is commonly referred to as the "ozone hole".
- In the stratosphere, CFCs come into contact with short wavelength ultraviolet radiation which is able to split off chlorine atoms from the CFC molecules
| CCl3F(g) | u.v radiation ---------------> |
CCl2F(g) | + | Cl(g) |
- These chlorine atoms destroy the ozone layer
| Cl(g) | + | O3(g) | -------------> | ClO(g) | + | O2(g) |
- There are significant numbers of oxygen atoms in the stratosphere (since ozone undergoes a natural photochemical decomposition producing oxygen atoms and molecules) which leads to the regeneration of chlorine atoms in the stratosphere.
So, 1 CFC molecule can destroy many ozone molecules.
| ClO(g) | + | O(g) | -------------> | O2(g) | + | Cl(g) |
Answered by | 10 Feb, 2013, 10:18: AM
Concept Videos
-
Environmental Chemistry
The video explains the formation and depletion of the ozone layer. -
Environmental Chemistry
This video explains the greenhouse effect and global warming. -
Environmental Chemistry
This video contains practice questions on ozone depletion, greenhouse effec... -
Environmental Pollution
This video explains about environmental polllution and pollutants. -
Introduction to Atmospheric Pollution ...
This video explains about atmospheric pollution and different layers of atm...
CBSE 11-science - Chemistry
Asked by Shwetadhana101 | 27 Feb, 2019, 08:34: AM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 23 Jun, 2016, 09:44: AM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 23 Jun, 2016, 09:38: AM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 23 Jun, 2016, 09:40: AM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
ANSWERED BY EXPERTCBSE 11-science - Chemistry
Asked by Topperlearning User | 04 Jun, 2014, 01:23: PM
ANSWERED BY EXPERT
