Question

Which is always present in photochemical smog?

• A. $O_3$
• B. $C{O}_2$
• C. $S{O}_2$
• D. $C{H}_4$

Answer 1

The correct option is A $O_3$

Photochemical smog formed by action of sunlight on
unsaturated hydrocarbons and nitrogen oxides.
Nitrogen oxides split into nitric oxide and nascent oxygen.
$N{O}_2\left(g\right)\stackrel{h\nu }{\to }NO\left(g\right)+O\left(g\right)$
Nascent oxygen forms ozone.
$O\left(g\right)+O_2\left(g\right)\rightleftharpoons O_3\left(g\right)$

So, the correct answer is ${}^{\prime }{O}_3^{\prime }$