Thermodynamics and Energy

Question 1

Thermodynamics

Answer 1

Predicts concentrations/activities of various species and phases if a reaction reaches equilibrium.

Question 2

System

Answer 2

Portion of universe we wish to study.
open - exchanges matter/energy with surroundings.
closed - does not exchange matter with surroundings.
isolated - exchanges neither matter nor energy with surroundings.

Question 3

First Law Thermodynamics

Answer 3

Energy neither created or destroyed.

Change in Enthalpy (E):
🔺E =q-w

Question 4

Exothermic

Answer 4

Releases heat energy

H<0

Question 5

Endothermic

Answer 5

Uses heat energy

H>0

Question 6

Second Law Thermodynamics

Answer 6

For spontaneous process, proceeds in the direction of increasing order.

Change in Entropy(S):
🔺S=q/t

Question 7

Energy State

Answer 7

Unstable: High potential energy
Stable: Low/no potential energy
Metastable: can remain in this position if activation energy is not met.

Question 8

Gibbs Free Energy

Answer 8

🔺G=🔺H -T 🔺S

Question 9

Spontaneous Process

Answer 9

🔺G<0

Question 10

Reverse Process is Spontaneous

Answer 10

🔺G>0

Question 11

Equilibrium

Answer 11

🔺G=0

Question 12

IF 🔺G <0
AND
🔺H<0 and 🔺S>0

Answer 12

Spontaneous at any T

Question 13

IF 🔺G <0
AND
🔺H>0 and 🔺S<0

Answer 13

Not spontaneous at any T

Question 14

IF 🔺G <0
AND
🔺H<0 and 🔺S<0

Answer 14

Spontaneous at Low T

Question 15

IF 🔺G <0
AND
🔺H>0 and 🔺S>0

Answer 15

Spontaneous at High T

Question 16

Total Gibbs Free Energy (molar)

Answer 16

🔺G = n🔺G products - n🔺G reactants

Question 17

Clasius Clapeyron Equation

Answer 17

dP/dT = 🔺S/🔺V

Question 18

S-V-T-P relationships

Answer 18

V and S of neutral substance always positive.

V usually increases with T and always decreases with P.

S always increases with T and usually decreases with P.

If V decreases with T, the S increases with P.