Which of the following gas is removed from the exhaust of a factory if scrubber is installed?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Sulphur dioxide
Option (1) Sulphur dioxide — Correct. A scrubber removes sulphur dioxide with a spray of water or lime.
Note: This question is from Chapter 16, Environmental Issues, of the pre-rationalised NCERT book. This chapter is not in the present NCERT book (2026-27). The extract below is from the pre-rationalised edition.
NCERT Extract (Pre-rationalised edition, Chapter 16, Environmental Issues):
Air Pollution and Its Control – “… The collecting plates are grounded and attract the charged dust particles. The velocity of air between the plates must be low enough to allow the dust to fall. A scrubber (Figure 16.1) can remove gases like sulphur dioxide. In a scrubber, the exhaust is passed through a spray of water or lime.”
