Why might Ketchup stored in a tin can lead to chemical contamination?
The acetic acid in the ketchup will react with the metal tin, forming a metal acetate that will pass into the ketchup.
Ketchup is acidic, having a pH of 3.9. The acidic component, acetic acid, will react with the metal tin. This reaction will result in a metal acetate that will contaminate the ketchup.
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