MadSci Network: Chemistry |
To a certain extent, any carbonated beverage will remove rust. This is because the gas used, carbon dioxide, when mixed with water, makes carbonic acid. To make rust, the iron oxidizes, which is why rust is also called iron oxide. What the carbonic acid does is drive the reaction the other way, which is called "reduction." If you read the ingredients of both Coke and Sprite, now that you know it's an acid doing the work, you can see why Coke works better - it also has phosphoric acid as an ingredient. Phosphoric acid is what does most of the work in Naval Jelly, a commercial product used for rust removal. This is also why the rust that isn't dissolved off turns black. It's because it's turning back into metallic iron.
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