When white powder fizzes when added to vinegar, it undergoes a chemical reaction known as an acid-base reaction. Vinegar is a weak acid, while baking soda is a weak base. When the two substances come into contact, they react to form carbon dioxide gas, water, and salt. The carbon dioxide gas produces the fizzing effect.

The chemical equation for this reaction is:

NaHCO3 + CH3COOH → CO2 + H2O + CH3COONa

The products of this reaction are carbon dioxide gas, water, and sodium acetate, which is a salt.