>Green potassium ferrioxalate solution exposed to light will turn yellow, and then brown, releasing carbon dioxide in the process. After keeping them in the dark for some time, they become green again. Adding small amounts of oxalic acid greatly helps to speed up the process.
I understand why they would turn yellow, but how can they turn back to green when keeping them in the dark? They absorb carbon dioxide passively somehow?
I understand why they would turn yellow, but how can they turn back to green when keeping them in the dark? They absorb carbon dioxide passively somehow?