Question

Which of the following oxides of nitrogen is a coloured gas ?

• A. $N_2O$
• B. NO
• C. $N_2O_4$
• D. $NO_2$

Answer 1

Answer: (D)

$NO_2$

Answer 2

Nitrogen dioxide $(NO_2)$ is a dark reddish brown gas. It is present in the earth’s atmosphere. The colour is due to the absorption of the sunlight in the blue and green regions of the visible spectrum. It is not involved in global warming but it can form other pollutants that will contribute to global warming.