Dry ice is extremely cold, with a temperature that is approximately -78 degrees Celsius (-109 degrees Fahrenheit).
Understanding Dry Ice Temperature
The unique characteristic of dry ice, which is the solid form of carbon dioxide, lies in its very low temperature. Unlike water ice, dry ice does not melt into a liquid when it warms up; instead, it undergoes a process called sublimation.
Sublimation Explained
- Definition: Sublimation is the direct transition of a substance from a solid state to a gaseous state without passing through a liquid phase.
- Dry Ice Behavior: At standard atmospheric pressure, dry ice will sublime directly into carbon dioxide gas when its temperature rises above -78°C (-109°F). This is why you often see a fog-like vapor (which is actually condensed water vapor from the air, not the CO2 itself) emanating from dry ice as it warms.
Key Temperature Facts
To provide a clearer perspective on how cold dry ice is, here's a comparison:
| Substance | Approximate Temperature |
|---|---|
| Dry Ice | -78°C (-109°F) |
| Water's Freezing Point | 0°C (32°F) |
| Typical Household Freezer | -18°C to -23°C (0°F to -10°F) |
Why Dry Ice Stays Cold
Dry ice maintains its extremely low temperature as long as it is in a solid state and is not in an environment that is significantly colder than -78°C (-109°F). If placed in a warmer environment, it will continue to sublime, absorbing heat from its surroundings and thus keeping things very cold until it has completely turned into gas.
