PHYS 112 Ch 2 (Second Law of Thermodynamics)

multiplicity

number of microstates for a given macrostate

multiplicity of macrostate / total multiplicity

probability of macrostate

total multiplicity

total number of microstates accessible to the system

paramagnet

particles of this material tend to align parallel to any externally applied magnetic field

weakly coupled

two systems are ___ when the exchange of energy between them is more gradual than the exchange of energy among atoms in each solid.

product

the total multiplicity of a combined system is the — of the multiplicities of the systems within the combined system

fundamental assumption of statistical mechanics

in an isolated system in thermal equilibrium, all accessible microstates are equally probable

irreversible behavior

when energy can flow spontaneously from one system to another, but cannot flow back (e.g. heat is released from the system

stops; macrostate; multiplicity

second law of thermodynamics: the spontaneous flow of energy —- when a system is at or very near the —- with the greatest __

thermal equilibrium; macrostate

once the system has had time to come to ——, such that all microstates are equally probable, it is in its most likely —-.

thermodynamic limit

the limit where a system becomes infinitely large, such that fluctuations away from the most likely macrostate never occur.

increase; increase

second law of thermodynamics: multiplicity tends to __, entropy tends to ——

volume; energy; number of particles

the entropy of an ideal gas depends on its —, —, and —

free expansion

when a gas expands spontaneously into a vacuum, doing no work and releasing/absorbing no heat, creating entropy due to the number of particles in the vacuum increasing

entropy of mixing

total increase in entropy due to expansion of volume as two different gases mix with each other

doesn’t

if you start with the same gas on both sides of a partition and allow them to expand, the entropy of the gas does not increase at all

irreversible

processes that create new entropy are —-

reversible

a process that leaves the total entropy of the universe unchanged is —-

wavefunction; energies; quasistatic

compression of a gas squeezes each ——, increasing the —-of all levels and therefore all particles in the gas; unless compression is sufficiently —-

reversible process

a process that can be reversed by changing the conditions of the system only infinitesimally