Question

Brass gets discolored in air because of the presence of which of the following gases in air?
A. Hydrogen sulphide
B. Oxygen
C. Nitrogen
D. Carbon dioxide

Answer 1

Hint- In order to solve this problem, first we will see the chemical composition of the brass alloys or the metal which are present in the alloy. Then on the basis of the reaction of the elements with the gases present in the air, we will select the correct option amongst the given ones.

Complete answer:
The brass alloy is made by the combination of Zinc and Copper.
Brass does not react with oxygen, nitrogen and carbon dioxide.
Because of the presence of Hydrogen sulphide, Brass is discolored in sunlight. This is because 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.
Hence, brass gets discolored in air because of the presence of hydrogen sulphide.

So, the correct answer is option A.

Note- Brass is the generic term for a range of copper-zinc alloys with different property combinations including strength, machinability, ductility, wear-resistance, hardness, colour, electrical and thermal conductivity, hygiene and corrosion resistance. Common uses for Brass include applications that require low friction because of its unique properties, which include corrosion resistance. These applications may include fittings (fittings and connectors), tools, equipment components and munitions components.