Entropy

Question 1

entropy

Answer 1

measure of disorder, randomness or uncertainty

Question 2

Helmholtz free energy

Answer 2

F = E - TS, used for constant vol

Question 3

Gibbs free energy

Answer 3

G = H = Ts, used for constant pressure

Question 4

G at equilibrium

Answer 4

minimum

Question 5

2nd law of thermodynamics

Answer 5

isolated system left at fixed energy moves to state with highest entropy

Question 6

3rd law of thermodynamics

Answer 6

dS for physical/chemical processes approaches 0 as T goes to 0 provided all substances are perfectly crystalline

Question 7

Boltzmann and entropy

Answer 7

S = kblnW

Question 8

residual entropy

Answer 8

due to disorder in lattice as T moves to 0

Question 9

cause of residual entropy in CO

Answer 9

CO has small dipole moment, small orientation dependent d-d interaction, means intermolecular interactions are dominated by valence repulsion/dispersion, these are weak giving no preference for orientation meaning even at low temps there’s still some disorder giving residual entropy

Question 10

why is calculated residual entropy generally < recorded

Answer 10

all orientations aren’t exactly equivalent, this is just an approximation