How does calcium carbonate react with vinegar?

Calcium carbonate produces a weak chemical reaction with vinegar, which is an acetic acid, by releasing carbon dioxide. A simple experiment that demonstrates the reaction is to soak an egg, which has a calcium carbonate shell, in vinegar, which completely dissolves the shell in a matter of days.

This experiment also works with chicken bones because calcium carbonate is what makes bones hard. Taking the egg or chicken bones out of the vinegar for approximately one day makes them hard again because they absorb the carbon dioxide that is naturally in the air. A small hole must be poked in the lid of the jar that the egg or chicken bones are in.