Question

Which of the following statements is not false?

• A. $S{O}_2$ does not affect larynx.
• B. $S{O}_2$ is more harmful air pollutant than $S{O}_3.$
• C. $N{O}_2$ is more toxic to living tissues than NO.
• D. $N{O}_x$ do not play any role in photochemical smog.

Answer 1

Answer: (C)

$S{O}_2$ affects larynx. $S{O}_2$ itself is not highly dangerous. However, when it is released to the atmosphere, it can react with oxygen in the air to form sulphur trioxide which irritates the mucous membrane of the respiratory tract.
$2S{O}_2+O_2\to 2S{O}_3$
Neither NO nor $N{O}_2$ is health hazardous at the present pollution level. Out of the two, $N{O}_2$ is more dangerous as it is a toxic gas and affects respiratory system and damages the lungs.
$N{O}_x$ are responsible for photochemical smog.