Q. Brass gets discoloured in air because of the presence of which of the following gases in air ?
A) Oxygen
B) Hydrogen sulphide
C) Carbon dioxide
D) Nitrogen
✔ Correct Answer: Hydrogen sulphide
Exam Insight
Brass gets discolored in air primarily due to the presence of sulfur dioxide (SO2), which reacts with the copper in brass to form copper sulfate, a tarnishing compound.