Chapter 19

Question 1

Spontaneous process

Answer 1

one that occurs without ongoing outside intervention; performance of work by some external force

Question 2

Entropy (S) + units

Answer 2

a thermodynamic function that increases with the number of energetically equivalent ways to arrange the compounds of a system to achieve a particular state
units: J/K

Question 3

equation for entropy

Answer 3

S = k lnW
- k = 1.38 x 10^-23
- W - number of energetically equivalent ways to arrange the components of the system

Question 4

Seconds law of thermodynamics

Answer 4

for any spontaneous process, the entropy of the universe increases

Question 5

the direction of chemical systems is determined by entropy

Answer 5

a direction that increases the entropy of the universe,
the direction that has the largest number of energetically equivalent ways to arrange its components

Question 6

delta S, q (rev), and T formula

Answer 6

delta S = q rev/ T
- q rev - heat exchanged with the surroundings in a reversible process
- T - Temperature in Kelvins

Question 7

Delta S (surr) formula

Answer 7

Delta S (surr) = delta H (sys)/ T

Question 8

A process that emits heat into the surroundings (delta H sys negative)

Answer 8

increases the entropy of the surroundings (positive delta S surr)

Question 9

A process that absorbs heat from the surroundings (delta H sys positive)

Answer 9

decreases the entropy of the surroundings (negative delta S surr)

Question 10

Gibbs free energy formula

Answer 10

G = H - TS
H - enthalpy
T - temperature
S - Entropy

Question 11

At Low temperature, H is negative, S is positive

Answer 11

spontaneous

Question 12

At High temperature, H is negative, S is positive

Answer 12

spontaneous

Question 13

At low temperatures, H is positive, S is negative

Answer 13

nonspontaneous

Question 14

At high temperatures, H is positive, S is negative

Answer 14

nonspontaneous

Question 15

At low temperature, H is negative, S is negative

Answer 15

spontaneous

Question 16

At high temperatures, H is negative, S is negative

Answer 16

nonspontaneous

Question 17

At low temperatures, H is positive, S is positive

Answer 17

nonspontaneous

Question 18

At high temperatures, H is positive, S is positive

Answer 18

spontaneous

Question 19

Standard entropy change for a reaction

Answer 19

S(products) - S (reactant)

Question 20

gibbs free energy under nonstandard conditions formula

Answer 20

delta standard G run + RTlnQ

Question 21

When K < 1, ln k is negatie, delta G rxn standard

Answer 21

spontaneous in reverse

Question 22

When K > 1, ln K is positive, delta G rxn standard

Answer 22

spontaneous in foward

Question 23

When K = 1, ln K is zero, delta G rxn standard

Answer 23

equilibrium