Question

Acid rain is caused by precipitation of . A) Oxides of sulphur B) CFCs C) Ozone

Answer 1

Acid Rain: Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by:

• Oxides of sulphur: In the gas phase sulfur dioxide is oxidized by reaction with the hydroxyl radical via an intermolecular reaction:

SO₂ + OH^- → HOSO₂^-

which is followed by:

HOSO₂^· + O₂ → HO₂· + SO₃

In the presence of water, sulfur trioxide (SO3) is converted rapidly to sulfuric acid:

SO₃ (g) + H₂O (l) → H₂SO₄ (l)

Nitrogen dioxide reacts with OH to form nitric acid:

NO₂ + OH^· → HNO₃

• CFC: CFCs are the chemicals that are used in industry, refrigeration, air conditioning systems, and consumer products. Whenever CFCs are released into the air, they reduce the stratospheric ozone layer. The stratospheric ozone layer protects Earth’s surface from the harmful rays of the sun.
• Ozone: Ozone is released by motor vehicles, industries, burning coal, gasoline, and other fossil fuels, and in the chemicals that are in hair spray and paints. When ozone is close to the ground (ground level ozone) it can cause chest pain, irritated respiratory tract, or persistent cough, can make you unable to take deep breaths, and can make you more likely to get lung infections.