Brass gets discolored in air because of the presence of which of the following gases in air?

Hydrogen Sulphide

The correct answer is Option (3) - Hydrogen Sulphide

The reason is that the presence of a mixture of hydrogen and sulphide and brass, which has a very light color and mixture with hydrogen sulphide leads to non-temperature (hot and cold temperature type) so it becomes discolored. Thus, presence of hydrogen sulphide leads to brass being discolored in the air.