Thread: How did my blade rust?

I did an experiment for school (8th grade) with iron nails in differnet liquids. The jars sat for 6 weeks. I thought the tap water, which is our well water run through a Culligan water softener and a cholination set up, would rust the iron nail more than the isopropyl alcohol, but I was wrong.

Why would the alcohol create more rust than tap water?

Answer
Water is what I would describe as a stable compound in terms of its physical properties. Over a pretty wide temperature range (0-100C) there really isn't a lot going on and it stays almost exclusiviely in the liquid phase. Isopropyl alcohol on the other hand is a lot less stable. Even at temperature in the range of the liquid phase, you have quite a bit of evaporation, as I'm sure you could smell. Both compound contain oxygen, so both will cause the nails to rust (oxidize). But due to increased kinetic energy in the alcohol (what is causing this evaporation to happen), chemical reactions are going to happen at an increased rate. Therefore, the alcohol will increase the rate of oxidation, leading to more rust.