[Oxoberylunol]

Hello,
I performed an experiment about the galvanic corrosion of Iron anode with a copper cathode under a CO2 environment by attaching a balloon to a test tube. At the beginning, some white specs formed, but the next day some brown rust (Fe2O3?) Formed. Several days later some green iron started precipitating.

[Borek]

Rust suggests there was some oxygen present.

[Enthalpy]

If you tried as well without copper and compared the corrosion of iron, I'm interested. Last time I tried there was no observable difference. Iron just corrodes in water. My opinion up to now is that there may be a difference sometimes, but only if the corrodible metal is very pure, or is a corrosion-resistant alloy.

[Oxoberylunol]

I wanted to figure out what products would form once oxygen is removed and CO2 became the oxidizing agent. My guess is that H2CO3 would form, evolving H2 at the cathode and forming FeCO3 at the anode, further decomposing into Fe2O3.

Mostly the purpose of this experiment was to see if CO2 can substitute O2 as an oxidizing agent.