Nothing really explodes. Together, baking soda and vinegar just produce a lot of gas. The two things together give off carbon dioxide, the gas. This makes the bubbles. The stuff in vinegar that makes it smell sharp is called acetic acid. The chemical name for baking soda is sodium bicarbonate. These two things, when mixed, make carbonic acid. Carbonic acid doesn’t like to stick around, and quickly converts itself into carbon dioxide plus water. Then the carbon dioxide escapes into the air (the bubbles), because gases are so light, and you are left with water. A true explosion would give off heat. This reaction just releases gas.
Answer provided by Dr. Universe