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 5 of 26.
ANAND SHARMA said:
1 decade ago
Actually brass constitutes of Cu+Zn, as it comes in contact of Hydrogen Sulphide, it transform into copper sluphate of blue color & zinc hydooxide of faint red color. Hence, it changes color.
Sandeep singh said:
1 decade ago
Hydrogen sulphide is (sulphur and oh-) so it is base and there is ph value is more than 7 so it is react with brass presence of air and discoloured the brass so hydrogen sulphide is right answer.
Anushadevi said:
1 decade ago
Because of the presence of hydrogen sulphide in Brass,it combines with oxygen in air and form water,evaporates.So remained sulphide is colourless in air .So Brass gets discoloured in the air.
Umar Ali said:
9 years ago
If option "b" (Hydrogen Sulphide) is the correct one then please can anybody tell me that, is hydrogen sulphide is present in the air? I think it is not and the correct answer is Co2.
Remo said:
9 years ago
I think option B is correct because brass is an alloy made of copper and zinc; the proportion of zinc and copper can be varied to create a range of brasses with varying properties.
Anomie said:
3 years ago
Brass does not react with oxygen, nitrogen and carbon dioxide. Because of the presence of Hydrogen sulphide, Brass is discolored in sunlight. Therefore, the answer is B.
(17)
Tsering said:
1 decade ago
As we know that zinc and copper is substituent of the brass so they get reacted with hydrogen sulphide. Also compare to other hydrogen sulphide is more electronegative.
Dev said:
1 decade ago
The Cu present in brass reacts with the sulphide ion of H2S forming CuS (cupric sulphide) which is black colored. Thus when brass is exposed to air it gets discolored.
Jeeva said:
1 decade ago
The Cu present in brass reacts with the sulphide ion of H2S forming CuS (cupric sulphide) which is black colored. Thus when brass is exposed to air it gets discolored.
Scholar said:
1 decade ago
In most of the answers it is said that sulphur reacts with brass but it cannot be ignored that hydrogen sulphide is a compound sulphur not only can react with brass.
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