Question

“Rate of reaction is also important from an environmental point of view.” Illustrate this statement with an example.

Answer 1

The clearest example of how reaction rates affect the environment is the depletion of the ozone layer.

• The Protective Shield: The ozone layer in the Earth’s upper atmosphere (stratosphere) protects life by absorbing harmful ultraviolet (UV) radiation from the sun.
• Two Opposing Reactions: There are constantly two chemical reactions happening in the atmosphere:
  • The continuous natural production of ozone molecules (O₃) from oxygen (O₂).
  • The natural and artificial destruction of ozone molecules (accelerated by pollutants like chlorofluorocarbons, or CFCs).
• The Importance of Rate: The thickness and health of the ozone layer depend entirely on the relative rate of these two reactions. If the rate of ozone destruction exceeds the rate of its production, the ozone layer depletes (creating an “ozone hole”). This allows dangerous UV rays to reach the Earth, leading to environmental damage, global warming, and health issues like skin cancer.