Question

Question 14.8 What are the harmful effects of photochemical smog and how can they be controlled?

Class XI Environmental Chemistry Page 413

Answer 1

HARMFUL EFFECTS OF PHOTOCHEMICAL SMOG :

1. all these compounds ( particularly ozone and peroxyacylnitrates, PAN ) produce irritation in the eyes and also in the respiratory system.

2. They damage many materials like metals , stones , building materials etc.

3. ozone is particularly distractive to rubber in which cracks are developed.

4. it is also harmful to fabrics , crops and ornamental plants .

5. NO2 present gives a brown color to the photochemical smog which reduces visibility , airplane pilots are familiar with this type of fog hanging over the cities.

HOW TO CONTROL OF PHOTOCHEMICAL SMOG :

1. by fitting efficient catalyst converters in the automobile so that emission of nitrogen oxides and hydrocarbons by these automobiles into the atmosphere can be prevented.

2. By spraying certain compound into the atmosphere which generate free radicals that readily combine with the free radicals that initiate the reactions formic toxic compounds of the photochemical smog.

3. certain plants like pinus , juniparus , pyrus, vitis, etc can matabolise oxides of nitrogen. Hence, their plantation could be helpful.

Answer 2

EFFECTS OF PHOTOCHEMICAL SMOG: Photochemical smog is oxidizing smog owing to the presence of NO2 and O3, causing corrosion of metals, stones, rubber, and painted surfaces. The other major components of photochemical smog are PAN, acrolein, and formaldehyde. Both PAN and ozone are eye irritants, while nitric oxide (formed from NO2) causes nose and throat irritation. At higher concentrations, photochemical smog causes chest pain, headaches, throat dryness, and various respiratory ailments.  CONTROL MEASURES: Photochemical smog results from the burring of fossil fuels and automobile fuels that emit NO2 and hydrocarbons, which in turn form ozone, PAN, and other chemicals. The use of catalytic converters in automobiles is recommended to prevent the release of NO2 and hydrocarbons into the atmosphere. Plantation of plants such as Pinus, Juniparur, Quercus, Pyrus, and Vitis is also advised as these plants have the capability to metabolize NO2.…………BY CHAITALI