Vinegar

• Vinegar is a diluted form of acetic acid. According to the Science Encyclopedia, "an acid is a substance that dissolves and forms ions of hydrogen." As vinegar dissolves, hydrogen atoms separate from the rest of the acid molecule and float freely in the solution.
  
  

Baking Soda

• Baking soda, also known as sodium bicarbonate, is a base. A base reacts opposite from the way an acid reacts. Instead of releasing hydrogen ions, baking soda accepts hydrogen ions.
  
  

When Acid Meets Base

• When vinegar and baking soda combine, the vinegar releases hydrogen atoms into the solution that are taken up by the baking soda. The chemical reaction changes the vinegar and baking soda into sodium acetate and carbonic acid. However, carbonic acid is unstable and quickly decomposes into water and carbon dioxide, which is the second reaction in the experiment. The fizzing during the reaction is the carbon dioxide escaping.
  
  

Results

• When an acid and a base react, the typical results are a salt and water. When vinegar and baking soda react, the result is sodium acetate, a salt, water and the release of carbon dioxide.
  
  

Precautions

• While the vinegar/baking soda experiment is one of the safest experiments to carry out, a few precautions should be observed. Vinegar, although mild, is an acid and will pit some surfaces like marble. Baking soda is an abrasive and care should be taken not to scratch sensitive surfaces.