I used lemon juice, vinegar and distilled water exposed to air as models for rainwater (acidic and normal rainwater) and used finest quality steel wool.
There was a rise in temperature, it occurred faster in acid rainwater models compared to normal rainwater model and was maximal at 2 min. for each acid. Both the rate of rise of temperature and the steady state temperature was highest for vinegar, an unexpected finding as it is less acidic than lemon juice (pH 3.09 vs. 2.60 respectively). The greatest temperature difference between ending and starting temperatures was also highest in Vinegar rainwater model. The mass of steel wool changed when measured 15 min after it was exposed to more acidic rainwater models (vinegar and lemon juice), but did not change with distilled water. Rust formation on steel wool was also greatest for vinegar model.
The results showed that the model of acid rainwater did cause rust formation, while model of normal rainwater did not. I observed a rapid rate of rise in temperature, a higher steady state temperature, a heavier mass and most rust formation with acid rainwater model (vinegar). The normal rainwater model (distilled water exposed to air) did not cause change in mass or rust formation. The more acidic liquid (lemon) did not cause more rapid rate of rise in temperature, so my 3rd hypothesis proved to be not true.
The project studied the effect of different acids on the rate of rusting.
Science Fair Project done By Kamran M. Jamil