It is all about surface tension!

Ever try to drop a mint Mentos into a bottle of diet coke? It is an explosive experience. An unopened diet coke is filled with carbon dioxide that gives the sensation of a carbonated beverage. The sugar coat of a mint Mentos actually breaks down the surface tension of the liquid, enabling the carbon dioxide to escape. Each Mentos consists of thousand of pores, a perfect site for carbon dioxide bubbles to form. Thus, when a few Mentos are dropped into a bottle of diet coke, a “Mentos Eruption” will happen. Check this cool video from eepybird.com.