I am testing the acidities of vawious drinks, so I put pennies in 7-up, a&w root beer, water, and red bull. I don't know if all the pennies are copper or not but they're all before 1985. I know the acids will atleast burn some particles off so my question is: What causes it to burn? Is it some reaction between the copper and the acid?
2007-06-10 09:21:04 · 2 answers · asked by daviditcher 1 in Science & Mathematics ➔ Chemistry
I hate to tell you but, the pennies changed in 1981.
They were a copper/zinc alloy before 1981.
After 1981 they are copper coated zinc.
The main acids you have are carbonic acid, citric acid. If the original container was aluminum, there may have been phosphoric acid. Each of these reacts with copper but more so with zinc. The copper/zinc alloy pennies, when the zinc reacts will appear redder than before.
2007-06-11 04:21:20 · answer #1 · answered by a simple man 6 · 0⤊ 0⤋
As all the drinks you mention are mostly carbonated,
(read 'fuming carbonic acid`), and thus very similar, and your test is not that sensitive, (copper is pretty stable), you are unlikely to see any difference with this approach.
2007-06-14 14:30:32 · answer #2 · answered by Irv S 7 · 0⤊ 0⤋