Topic 4- Lecure 17

Question 1

Non- thermodynamically favored processes

Answer 1

Assistance from outside of system is necessary in order to induce the desired change
Non spontaneous

Question 2

Exothermic reactions are often thermodynamically favored

Answer 2

-

Nature tends to favor processes that cause a reduction in energy

Question 3

Endothermic reactions CAN be thermodynamically favored

Answer 3

Not usually

+

Question 4

Entropy

Answer 4

Measure of disorder in a reaction
Disorder is favorable
+ is favorable

Question 5

Entropy equation

Answer 5

ΔS= S (products) - S (reactants)
ΔS= ΣnS° (products) - ΣnS° (reactants)
Sum of 
Stoichiometric coefficients
Look up in table

Question 6

ΔS is positive

Answer 6

Products contain more miles than reactants
Adding heat
Increasing volume

Question 7

ΔH that is - equals

Answer 7

ΔS that is positive

Greater degree of disorder

Question 8

Heat flow links…

Answer 8

System to surroundings

Question 9

Exothermic

Answer 9

S increases

System loses heat S>0

Question 10

Endothermic

Answer 10

S decreases
System gains heat
S

Question 11

Gibbs free energy

Answer 11

ΔG= ΔH- TΔS
ΔG°rxn= ΣnΔG°f (products) - ΣnΔG°f (reactants)
Free energy kJ
Enthalpy change
Temp of system K
Entropy change kJ/K
Find values on table for 2nd equation

Question 12

T=

Answer 12

ΔH over

ΔS

Question 13

-ΔH

+ΔS

Answer 13

TFP at all temps

Question 14

+ΔH

-ΔS

Answer 14

Non TFP at all temps

Question 15

• ΔH

- ΔS

Answer 15

TFP at low temps

Non TFP at high temps

Question 16

+ΔH

+ΔS

Answer 16

TFP at high temps

Non TFP at low temps

Question 17

Thermodynamically favored process

Answer 17

TFP
Proceeds without any assistance from outside the system
Happens at standard conditions
Spontaneous

Question 18

G is wanted to be

Answer 18

Negative

Question 19

H is wanted to be

Answer 19

Negative

Question 20

S is wanted to be

Answer 20

Positive