Dry ice and its properties
The environmental conditions of pressure and temperature determine the physical state of the carbon dioxide: gas, liquid or solid. Under atmospheric conditions, the dry ice sublimates. Carbon dioxide is one of the few substances which, under the temperature and pressure conditions on earth, exist either in a solid or gaseous state.
When warming it from -78.5°C (194.65 K) to 0°C (273.15 K), the refrigerating capacity of dry ice is approx. 640 kJ/kg, which corresponds to approx. 3 times the refrigerating capacity of conventional ice. However, the possibly more important advantage is that after evaporation there is «nothing» left over, which is not the case with normal ice made from water. When heat is applied, the dry ice immediately changes into its gaseous state.
