Effects

• Submerging a raw whole egg in a jar of white vinegar and refrigerating for 72 hours produces a "rubber egg" because the vinegar dissolves the egg shell surrounding the inner membrane of the egg.
  
  

Features

• Egg shells are composed of calcium carbonate, an organic compound also found in limestone, chalk, marble and coral. Vinegar contains acetic acid, the substance that gives vinegar its sour taste.
  
  

Function

• The acetic acid in the vinegar breaks down the calcium carbonate crystals in the egg shell into separate calcium and carbonate parts with the by-product of water. The calcium part takes the form of calcium ions, suspended in the vinegar and water. The carbonate part takes the form of carbon dioxide gas which bubbles off as the egg shell dissolves.
  
  

Significance

• The calcium ions are calcium atoms that are stripped of two electrons. The pair of stripped electrons bind with two hydrogen ions in the acetic acid of the vinegar to form two hydrogen atoms which, in turn, bind with one oxygen atom from the carbonate part of the calcium carbonate to form a molecule of water. The other two oxygen atoms of the carbonate part remain bound to the carbon atom of the carbonate part to form a molecule of carbon dioxide gas.
  
  

Identification

• Acid-base chemical reactions are characterized by the swapping of electron pairs between the electron donor (the base) and the electron acceptor (the acid). The chemical reaction demonstrated by the "rubber egg" experiment is: CaCO³ + 2H+ -> Ca+² + H²O + CO².
  
  

Fun Fact

• You can also make "rubber bones" by soaking thin chicken bones in vinegar because calcium carbonate is also found in bones.