In air pollution, oxides of nitrogen (NOx) include which of the following? Choose the correct answer from the options given below.

1.Nitric oxide

2.Nitrous oxide

3.Nitrogen dioxide

4.Di-nitrogen trioxide

5.Di-nitrogen pentoxide

A1, 2 and 3 only

B1 and 3 only ✓ Correct

C2, 3 and 4 only

D4 and 5 only

Correct answer: (B) 1 and 3 only

Explanation

In air pollution, oxides of nitrogen chiefly mean nitric oxide and nitrogen dioxide.

Statement 1, nitric oxide, is a primary NOx gas from combustion.

Statement 3, nitrogen dioxide, is the other main NOx gas and a criterion pollutant.

Statement 2, nitrous oxide, is a greenhouse gas usually excluded from the NOx group.

Statements 4 and 5, di-nitrogen trioxide and pentoxide, are minor species not counted as regulatory NOx.

NOx forms mainly at high combustion temperatures in vehicles and power plants.

Want more like this? Create a free account to practise a full test, track your progress, and get spaced-repetition review.