Physics Ch 3. Thermodynamics Flashcards
Zeroth law of thermodynamics
States that objects are in thermal equilibrium when they are at the same temperature, objects in thermal equilibrium experience no net exchange of heat energy
Temperature
Qualitative measure of how hot or cold an object is, quantitatively it is related to the average kinetic energy of the particles that make up a substance
Thermal expansion
Describes how a substance change is in length or volume as a function of the change in temperature
Thermodynamic system
The portion of the universe that we are interested in observing
Surroundings
Include everything that is not part of the system
Isolated systems
Do not exchange matter energy with the surroundings
Closed systems
Change energy but not matter with their surroundings
Open systems
Exchange both energy and matter with their surroundings
State functions
Are pathway independent and are not themselves defined by a process, examples include pressure, density, temperature, volume, enthalpy, internal energy, Gibbs free energy, and entropy
Process functions
Find the pathway from one equilibrium state to another, examples include work and heat
First law of thermodynamics
Statement of the conservation of energy, the total energy in the universe can never decrease or increase
Closed system energy
The total internal energy is equal to the heat flow into the system minus the work done by the system
Heat
The process of energy transferred between two objects at different temperatures that occurs until the two objects come in to thermal equilibrium or reach the same temperature
Specific heat
Is the amount of energy needed to raise 1 g of a substance by 1°C or one Calvin, the specific heat of water is 1 cal/g/K
Phase change energy change
Heat energy causes changes in the particles potential energy and energy distribution (entropy) but not kinetic energy, therefore no change in temperature, this is the heat of formation
