Can an Isolated System exchange energy or matter with the surroundings
no exchange of energy (heat or work) with surroundings
ex: insulated bomb calorimeter
Can a Closed System exchange energy or matter with the surroundings
exchange of energy (heat or work) but not matter with surroundings
ex: steam radiator
Can an Open System exchange energy or matter with the surroundings
exchange of energy (heat or work) and matter with surroundings
ex: pot of boiling water
what is a process
changing in one of the properties of a system
equation for delta U
delta U = Q - W
change in internal energy of a system = heat added - work done by system
FIRST LAW OF THERMO
what occurs in an isothermal process
- temperature is constant
- U (total internal energy) is constant, delta U = 0
- Q = W
what occurs in an adiabatic process
- no heat is exchanged between system and environment (temperature can change)
- Q = 0
- delta U = - W (change in internal energy = work done on the system)
what occurs in an isobaric process
- pressure is constant
- delta U = Q - W
what occurs in an isovolumetric (isochoric) process
- volume is constant
- no change in volume = W = 0
- delta U = Q
how is a spontaneous process driven
occurs internally WITHOUT drive by outside energy source
what is accomplished by coupling
energy for nonspontaneous rxns is supplied by linking them with spontaneous rxns
state functions
properties of a system at equilibrium
- pressure (P)
- density (p)
- temperature (T)
- volume (V)
- enthalpy (H)
- internal energy (U)
- Gibbs free energy (G)
- entropy (S)
process functions
properties of a system in flux
- work (W)
- heat (Q)
standard condition
- 25 degrees C (298K)
- 1 atm
- 1 M con’c
used for kinetics, e’q, and thermo, measuring H, G, S
standard temperature and pressure
- 0 degrees C (273K)
- 1 atm
used for ideal gas calculations
what is the standard state of a substance
the most stable state of the substance under standard conditions
evaporation/vaporization
liquid to gas phase change
molecules near the surface of liquid have enough kinetic energy to escape into the gas phase
condensation
gas to liquid phase change
molecules are forced by a lower temperature or higher pressure back into the liquid phase
fusion/melting
solid to liquid phase change
molecules in the solid absorb enough energy to break into liquid phase
solidification/crystallization/freezing
liquid to solid phase change
sublimation
solid to gas phase change
deposition
gas to solid phase change
triple point
point at which three boundaries meet on a phase diagram
critical point
point at which the phase boundary for liquid and gas terminate
(no distinction between the phases at this point)
