• # question_answer 23)   Which of the following statements is not true about classical smog? (a) Its main components are produced by the action of sunlight on emissions of automobiles and factories. (b) Produced in cold and humid climate. (c) It contains compounds of reducing nature. (d) It contains smoke, fog and sulphur dioxide.

(a) Classical smog is initiated by a mixture of$S{{O}_{2}}$, particulates and high humidity in the atmosphere in cold conditions. A fog of $S{{O}_{2}}$ droplets formed condense on particulates to form smog. It is of reducing nature. The gases released by automobiles and factories are not responsible for classical smog.