Which of the following is not a common component of photochemical smog?

Which one of the following substances used in dry cleaning is a better strategy to control environmental pollution?

Which free radical is responsible for the depletion of the ozone layer?

The irritant red haze in traffic and congested places is due to the presence of which of the following?
$(i)$ Oxides of sulphur
$(ii)$ Oxides of nitrogen
$(iii)$ Carbon dioxide
$(iv)$ Mists,smoke and dust
$(v)$ Smog

How is ozone gas produced in the stratosphere?

Which of the following chemicals is not involved in photochemical smog formation?