Answer;
-During sublimation
Explanation;
-Carbon dioxide in its solid form is known as “dry ice,” because under common conditions it sublimates, turning directly into gas, rather than melting into liquid.
-The enthalpy of sublimation, or heat of sublimation, is the heat required to change one mole of a substance from solid state to gaseous state at a given combination of temperature and pressure,
-The low temperature and direct sublimation to a gas makes dry ice an effective coolant, since it is colder than water ice and leaves no residue as it changes state. Its enthalpy of sublimation is 571 kJ/kg
