What happens is more a kinetic phenomenon than a thermodynamic one, and more a physical reaction than a chemical one. The carbon dioxide is first introduced into the drink under several atmospheres'atmospheres pressure, soitso it becomes a supersaturated solution. When the water is cooled and forms ice crystals,the the ice crystals act as nuclei for the carbon dioxide gas to "boil". This converts its latent potential (fugacity) to actual pressure, which explodes the can.