General Knowledge - General Science - Discussion
Discussion Forum : General Science - Elements and Metals (Q.No. 1)
1.
Brass gets discoloured in air because of the presence of which of the following gases in air?
Discussion:
254 comments Page 6 of 26.
Swayamprava dikshit said:
1 decade ago
brass is an alloy of zn & cu. in present of atmosprere it reacts as
zn+cu+h2s=cu2s+znh.
cu2s coloured the alloy black & znh brings colours of faint red.
zn+cu+h2s=cu2s+znh.
cu2s coloured the alloy black & znh brings colours of faint red.
Dev said:
10 years ago
Actually, Brass is not a simple metal but an alloy i.e. a mixture of Cu and Zn. Generally sulphur in air is very reactive to copper mixtures. So the answer is B.
Saurabh Agrahari said:
8 years ago
A is a better option because reactive free oxygen species is helpful to discolour the brass because free radical of oxygen may present which is react with brass.
Hitesh said:
8 years ago
In my opinion option A is correct as we see in fruits such as apples and bananas they get brown colour in coming in contact with air and because of oxygen it is.
AHAMED HALITH said:
6 years ago
Yes, H2S is the correct one because sulphide gas is poisonous and if it is combine with H it becomes poisonous acid so it makes brass discoloured.
Raghava said:
4 years ago
Brass does not react with oxygen, nitrogen and carbon dioxide. . Hence, brass gets discolored in air because of the presence of hydrogen sulphide.
Sushma said:
1 decade ago
I think B is the correct option Since the brass is an alloy of transition elements Zn and Cu,it reacts with hydrogen sulphide to get discolored
Prani said:
1 decade ago
Brass is an alloy of Cu and Zn, when it comes in contact with H2S it forms zns and Cu2s which are black in colour hence brass gets discolured.
Aoke Soe Paing said:
1 decade ago
The question is "which of the following gases". So the answer may be two or more gases. I think that as both of oxygen and H2S are in the air.
Abhigna said:
1 decade ago
I think it will not discolour. It may become black in colour, because of the presence of CU and Zn. If it react with H2S it forms CuS AND ZnS.
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