Exam 2 ch 18

Question 1

Gibs free energy

Answer 1

^G = ^H - T^S

^H: Enthalpy
T: Temp
^S: Entropy

-Measures spontaneity
-Kj/mol

Question 2

Delta G sign meaning

Answer 2

Negative = Spontaneous, reaction proceeds towards products

0 = system is at equilibrium

Positive = non spontaneous, favors reactants but some product may be found

Question 3

Hess law with G or S

Answer 3

-Works the same way, you can reverse/multiply/divide these values

Question 4

Entropy

Answer 4

-Measure of randomness
-Solid > liquid > gas increasing entropy
-moles increase = entropy increase

Question 5

Second law of thermodynamics

Answer 5

-Entropy of the universe increases for all processes

-If system decreases, surroundings increase etc

Question 6

Delta S and Delta H signs

Answer 6

s to l +S, +H
l to s -S, -H

l to g +S, +H
g to l -S, -H

Question 7

Finding boiling/freezing point at equillibrium

Answer 7

delta H/delta S = T

Solve for T

-Fusion for freezing
-Vap for boiling

Question 8

K and C conversion

Answer 8

C = K - 273
K = C + 273

Question 9

S universe

Answer 9

S surr + S sys

Question 10

How to check when a reaction will go from being spontaneous to non

Answer 10

Delta H/ Delta S = T

Replug in and see if its negative higher or lower temp