What happens when you mix Pepsi and Mentos?

Mixing Pepsi and Mentos causes a rapid and dramatic eruption of soda from the bottle, accompanied by a loud pop or bang. This réaction is attributed to the reaction between the gelatin and gum arabic in the Mentos candy and the carbon dioxide in the soda. The gelatin and gum arabic act as nucleation sites, providing countless centers for the dissolved carbon dioxide gas to form bubbles, resulting in a rapid and massive release of gas. The high surface area of the Mentos also contributes to the enhanced nucleation process.

The explosive reaction is not limited to Pepsi, but can occur with other carbonated beverages as well. The specific ingredients in both the Mentos candy and the soda influence the intensity and behavior of the reaction, but typically involve the formation of a large foam and the rapid expulsion of liquid from the bottle.

It is worth noting that while this réaction is visually striking, it is not harmful and poses no health risks. Mixing Mentos with Pepsi or other carbonated beverages simply results in a fizzy, erupting soda fountain-like display.