2007-03-15 05:28:47 · 7 answers · asked by Selva r 1 in Science & Mathematics ➔ Engineering
Due to the surface oxidation
2007-03-15 05:34:39 · answer #1 · answered by sss 3 · 1⤊ 0⤋
Copper can go various ways - with sulphur in the atmosphere you often get a blue/green deposit - copper sulphate - think of copper fittings in the local urinal.
With oxygen - especially if the pipe is heated, then copper oxide will form which is blackish.
The short answer to your question is "Copper is a reactive metal"
2007-03-15 05:37:17 · answer #2 · answered by Mark T 6 · 0⤊ 0⤋
Cu attains a high position in the reactivity series.
Hence readily reacts with atmospheric oxygen & forms copper oxide which is black
2007-03-15 05:46:58 · answer #3 · answered by Anonymous · 0⤊ 0⤋
That is black copper sulfate (copper oxide is green). It is caused by a reaction with sulfurous pollutants in the air (like hydrogen sulfide).
2007-03-17 16:27:34 · answer #4 · answered by Rich Z 7 · 0⤊ 0⤋
It reacts with oxygen and other gases . Copper oxide
2007-03-15 05:32:50 · answer #5 · answered by Don 3 · 1⤊ 0⤋
It oxidizes (reacts with atmospheric O2).
2007-03-15 05:33:55 · answer #6 · answered by D 2 · 1⤊ 0⤋
In simple words.. that is copper rust.
2007-03-15 11:31:41 · answer #7 · answered by Baski 2 · 0⤊ 0⤋