cuco3

[asto5]

hey, just wondered if CuCO3 oxidises in air. if so how quickly would it do so.

cheers in advance

p.s is it... just wondered or just wandered??

[truetoon]

i don't know about the chemistry question but it is wondered, wandered is when you go walk about.

[shammydodger]

Copper carbonate does indeed oxidise in air, albeit very slowly. In typical moist air, it will oxidise to copper(II) hydroxide.

"Very slowly" would be measured in decades if not centuries, I would think.

[shammydodger]

Continuing from my previous answer, copper carbonate will also oxidise in air to copper(II) oxide. This oxidation, however, requires high temperatures; the sort of temperatures provided by a flame. So you can safely store your copper carbonate in the UK, even in these days of global warming.

[Gef]

Copper(II) carbonate cannot be oxidised. If it is heated it decomposes into copper(II) oxide and carbon dioxide but this is decomposition not oxidation as the copper is still in the +2 oxidation state.

[shammydodger]

While the heating of copper carbonate is indeed decomposition, it is also regarded as oxidation in the sense that the percentage composition due to oxygen (of the coppric compound) has increased. Similarly for the slow transformation of copper carbonate to copper hydroxide. I agree that these are not redox reactions, however.

[shammydodger]

cupric

[shammydodger]

Gef

I'll correct myself. Thermal decomposition of copper carbonate is not oxidation, as the percent oxygen has decreased. Can't believe I stated otherwise without doing some simple maths.

However, I retain my position that oxidation can occur without a change in oxidation state.

[AGENT X]

thus the reason recyclers would rather have copper wires stripped of their casing and not have the casing burnt off.