Re: Why does Coca-Cola eat away at metal, but is still drinkable?

"There is obvious erosion on the pennies after a week of sitting in a cup of 
Coke." Look at the time scale in your question. How long does Coke sit in your 
mouth? If you held Coke in your mouth for a week, your teeth would erode, too. 
As a matter of fact many dentists think the high use of sugary soft drinks among
children is to blame for the increase in tooth decay in that age group.

The pH of the stomach is about 1, which is lower than that of Coca-Cola. I 
suggest you measure its pH and find out!

Dan Berger
MadSci Administrator