How much phosphoric acid is in pepsi?

I can't tell you exactly the percentage that's in a tin, but i can tell you two simple expiraments to do with Coca-Cola and a Pepsi. Take two chalks put them into two different empty wine bottles the one with Pepsi and the other with coca-cola. Weight the two chalks with a precision scale before you put them in the bottles with the drinks. after 2-3 days remove them, let them dry and weight them again. See which chalk has lost more "weight". and compare. Just because i have never tried this expirament so i really don't know the tolerance of a chalk how much can last into a liquid with out melting, i don't want you to find at the bottom of the bottle dust of calcium carbonate i suggest you to do the second expirament first.The other is to find a test stripe which changes color if contacts acid. The strips contain a diazonium salt and as a stabilizer at least one phosphoric acid triamide that will react with the acid.