Dry Ice Sublimation

**Dry ice** is the solid form of **carbon dioxide**. It is used in a cooling process. We can use it for preserving frozen foods or materials, where cooling by refrigerator is not available. Dry ice sublimates at **−78.5 °C** at normal atmospheric pressure. It is called dry ice because it changes directly from a **solid to a gas (sublimation)** in normal atmospheric conditions without going through a wet liquid stage. Dry ice gives more than twice the cooling energy per weight and three times the cooling energy per volume than regular water ice.