When copper wire turns black over a flame is it a chemical reaction or a physical reaction.?

Question

and why does it does it turn black

Answer 1

It's a chemical reaction. the high heat of the flame is actually causing the wire to become a new form of matter. A physical change is a change that doesn't change the composition of the wire, like coating the wire with plastic. Burning the wire changes the chemical compositon of the wire. Also, signs of a chemical change in anything include burning, fumes/weird smell, a change in color.

Answer 2

Not quite so simple as oxidation. If oxidation were the only reaction occurring copper would turn black (CuO2) or less likely red (Cu0) and then black. The reaction turning copper green (verdigris as seen on the coppered roofs of churches etc) is due to partial oxidation followed by reaction with carbon dioxide to form the water insoluble blue/green copper carbonate which slowly builds to give such a beautiful green patina to the metal surface.

Answer 3

It is a chemical reaction. A physical reaction can be reversed. An example of a physical reaction would be melting ice, or bending a nail.

Answer 4

Physical Reaction, the black over the copper is caused by the Carbon smoke, its like "Soot" pretty much.

Answer 5

Chemical, the top layer of the copper under went rapid oxidation

Answer 6

Physical reaction. It's still copper, but the outside color, which is a physical characteristic, just changed.

Answer 7

It depends...If you can wipe it off, it's probally soot from the flame.
If it's physically part of the wire, it's probally copper oxide (which is black) and that would be a chemical reaction.
2Cu + O2 ---> 2CuO (Copper (II) Oxide)

Answer 8

it is a physical change... when the copper is heated, it changes colour.. therefore its physical condition is changing, there are no chemicals involved in the process

Answer 9

yes it should be chemical coz i learn from chemistry that copper oxidise when mix with air.

Answer 10

Definatly physical.