Science Buddies: "Ask an Expert"

I'm doing this Science Buddies experiment: https://www.sciencebuddies.org/science- ... p079.shtml
And I'm having some confusing issues.
--First of all, the prompt didn't mention what the actual *rate of corrosion* was, and since I haven't learned it yet and I'm in 8th grade, I was wondering if it could be explained since I did look it up and didn't really get it....
--Also, I don't understand why exactly I have to measure the temperature in this project, since I don't really see why it's relevant, could this be furthered explained? My understanding is when I'm getting my results, it is mainly significant whether the pH is higher or lower than the control, but what would that generally be? Or do I average it out myself with my own control then compare?
--And someone suggested to me that I use another control other than the distilled water, by also leaving the steel wool exposed to oxygen. How long (years?) would it take the steel wool to corrode?
--And finally, I borrowed test tubes from someone and I got the wrong size, instead of 55 ml i got like ten 10 ml tubes or something, so I know i have to scale down everything, and so far I calculated it to: 1 in. steel wool : 55 ml = 1.2 cm : 10 ml, and 1 cup to 55 ml = 47 ml to 10 ml. Is this correct and will my experiment still work?
Thanks!

Hey,

To answer one of your questions (about the temperature), the rationale can be found in the write-up:

"When iron and oxygen combine to make iron oxide (rust), heat is given off, which means the reaction is exothermic (exo means "out" and therm means "heat," so heat is sent out when the reaction occurs). With a thermometer and a timer, you can measure how fast heat is being given off (the rate), and that will give you an idea of how fast the reaction is occurring."

Basically, rusting is a chemical reaction. More specifically, it is an exothermic one (meaning heat is given off). So the quicker it gets hot, you know the rate of corrosion is higher.