Chapter 18: Thermodynamics Flashcards
(65 cards)
The science of thermodynamics was developed in
The early 19th century
Early thermodynamics invoked macroscopic ideas such as
Mechanical work, pressure, and temperature
The foundation stones of thermodynamics are
1) The conservation of energy
2) The fact that heat flows spontaneously from hot to cold and not the other way around
Absolute zero
There is no upper limit to temperature
Absolute zero was the molecules have
Lost all available KE
When the temperature of a gas change, the volume of the gas also
Changes
At zero degrees with pressure constant volume changes by
1/273 for each degree Celcius
Absolute temperature scale is
Kelvin Scale
No negative number on
Kelvin Scale
Absolute zero was
0 K
First Law: When heat flows to or from a system, the system gains or loses an amount of energy equal to
The amount of heat transferred
System:
Group of atoms, molecules, particles, or objects
Three types of systems
1) Open system
2) Closed system
3) Isolated system
1) Open system
System can exchange both matter and energy with surroundings
2) Closed system
System which can exchange only energy with surroundings
3) Isolated system
System in which neither energy nor matter can be exchanged with surroundings
If we add heat, Q, to a sytem, two things can happen:
1) It increases the internal energy, U, of the system (if it remains in the system)
2) It does work on things external to the system (if it leaves the systems)
Heat added equal to
Increase in internal energy plus with external work done by the system
Q equal to (theta U) plus with
W
First Law of Thermodynamic is a restatement of
The law of conservation of energy
Energy can neither be
Created nor destroyed
Positive heat in, the positive work
Out of the convention
When work is done on a system, for example, compressing air in a tire pump, the temperature of the system
Increases
Adiabatic processes
One of the thermodynamic processes which occur without any heat transfer between the system and the surroundings
