Energy Dispersal Flashcards
Entropy
a measure of how spread out the energy is; how are the increments of energy being distributed
qrev
the heat transfer of energy for a reversible process
Entropy change (∆S)
qrev/T
State
particle identities, quantities, and phases present; volume; temp
Microstate
a specific configuration of the energies of a system; one way of distributing the energy in a system
Modes of motion for a microstate (for each particle in a system)
translation, rotation, vibration
Distributions
microstates with equivalent particle arrangements that are grouped together
What is the most probable distribution?
the one of the greatest entropy
When does entropy increase?
increase in temp, more atoms in a system, more complex molecules, going from solid to liquid or liquid to gas, heavier molecules, gas expanding, particles mixing
3rd law of thermodynamics
the entropy of a pure, perfect crystalline substance at 0K is zero; saying there is only 1 microstate possible
Standard entropy (Sº)
the absolute entropies per mole of substance at a pressure of 1 bar
Standard entropy change (∆rSº)
∑Sºproducts - ∑Sºreactants; make sure to pay attention to coefficients
2nd law of thermodynamics
all changes that take place of their own accord (spontaneous) involve an increase in entropy of the universe (∆Suniv>0)
What does ∆Suniv = 0 mean?
the system is at equilibrium