Lecture 1 Gibbs Energy

Question 1

define gibbs free energy

Answer 1

the maximum amount of non-expansive work done during a thermodynamic process

Question 2

equation for gibbs free energy

Answer 2

G = H - TS

Question 3

what values of gibbs free energy are non-spontaneous processes

Answer 3

larger than 0

Question 4

what value of gibbs free energy are spontaneous processes

Answer 4

smaller than 0

Question 5

what values of gibbs free energy are at equilibrium

Answer 5

0

Question 6

process of molecular self-assembly in solid/vacuum interface

Answer 6

adsorption
diffusion
no desorption

Question 7

process of molecular self-assembly at solid/liquid interface

Answer 7

adsorption
diffusion
desorption

Question 8

is molecular self assembly at a solid vacuum interface spontaneous

Answer 8

yes it has delta G smaller than 0
delta H much smaller than 0
irreversible

Question 9

how to find gibbs free energy with products and reactants free energy

Answer 9

products - reactants

Question 10

what conditions is gibbs energy defined at

Answer 10

constant temperature and pressure

Question 11

what do we get at conditions of constant temperature and volume

Answer 11

Helmholtz energy A

Question 12

conditions for standard gibbs energy

Answer 12

pressure 1 bar

concentration 1 moldm^-3

Question 13

how does temperature affect gibbs free energy

Answer 13

the higher the temperature the lower the free energy
gradient of -S
steep for gas less steep for solid and liquid

Question 14

what does a stand for

Answer 14

thermodynamic activity

Question 15

definition of thermodynamic activity

Answer 15

the effective concentration of the component

Question 16

equation for thermodynamic activity of an ideal gas

Answer 16

a = p/p standard conditions

Question 17

equation for thermodynamic activity for an ideal solution

Answer 17

a = [A]/[A] standard conditions

Question 18

equation for thermodynamic activity of a pure liquid or solid

Answer 18

a (pure solid) = a (pure liquid) = 1

Question 19

why define an equation using activity for gibbs free energy

Answer 19

can have dependence on pressure or concentration

Question 20

equation for gibbs free energy referring to activity

Answer 20

G = Gstandard conditions + RT ln a

Question 21

what conditions are ideal

Answer 21

dilute solutions

non-interacting gases at low temperatures

Question 22

what is a in real systems

Answer 22

effective concentrations

Question 23

equation for effective concentrations

Answer 23

aA = upsilonA [A]

Question 24

when does upsilonA stand for

Answer 24

activity coefficient

Question 25

what values can activity coefficient be

Answer 25

less than 1

Question 26

other name for molar gibbs energy

Answer 26

chemical potential

Question 27

equation for molar gibbs energy

Answer 27

mu i = (backwards deltaG/backwards delta ni)
ni = number of mols of compound
i and nj are the number of mols of other compounds

Question 28

what is chemical potential independent of

Answer 28

number of mols of the system