PP Presentation
- ENERGY is the capacity to do work or transfer heat.
- HEAT is the form of energy that flows between
2 samples because of a difference in temperature.
- WORK is the form of energy that results in a
macroscopic displacement of matter such as
gas expansion or motion of an object (force x distance)
In CO2 sublimation & expansion, the same amount
of ENERGY flows from surroundings to system
If expanding gas is enclosed, part of the energy transfer appears in the form of WORK OF EXPANSION
wexp = - PDV (for an ideal gas)
If expanding gas is not enclosed, the energy transfer appears
only as HEAT (CO2 gas gets warm).