Sidewalk chalk is made from calcium and sulfate, which makes calcium sulfate. One of the most common chemicals connected to calcium is called “carbonate”, and together they make calcium carbonate.

The eggshell is made of calcium carbonate. When it reacts with vinegar (acetic acid), it breaks down into water, carbon dioxide (the bubbles you see), and calcium acetate. The egg is held together by ...

Vinegar is also great at removing limescale. “Acetic acid in vinegar can be used at home to remove limescale – the calcium carbonate is converted into calcium acetate which is water-soluble ...