Question

Difference between Classical smog (London smog) and Photochemical smog (Los Angeles smog).

Answer 1

Classical smog (London smog)	Photochemical smog (Los Angeles smog)
This type of smog was first observed in London in 1952.	This type of smog was observed in Los Angeles in 1950.
It is formed due to presence of SO2 and humidity in the air which combine to form H2SO4 fog which deposits on the particulates.	It is formed due to photochemical reaction taking place when air contains NO2 and hydrocarbons.
It involves smoke and fog.	It does not involve any smoke or fog. The word smog is a misnomer here.
It is formed in the months of winter particularly in the morning hours when the temperature is low.	It is formed in the months of summer  during afternoon when there is bright sunlight so that photochemical reactions can take place.
It causes bronchitis irritation, i.e., problem in the lungs.	It causes irritation in the eyes. during afternoon when there is bright sunlight so that photochemical reactions can take place.
It is reducing in character.	It is oxidizing in character.