Chem 175 - Chapter 18 Chemical Thermodynamics (Exam 4)
ACTUAL EXAM 2026/2027 AND HIGH YIELD PRACTICE
QUESTIONS COMPLETE ACCURATE EXAM APPROVED
QUESTIONS AND CORRECT VERIFIED SOLUTIONS (100%
CORRECT VERIFIED ANSWERS) CURRENTLY UPDATED
VERSION 2026 EDITION |GUARANTEED PASS
1st Law of Thermodynamics
- total energy of the universe is constant; energy is neither created
not destroyed, but it can be transferred
2nd Law of Thermodynamics
- spontaneous processes always result in an overall increase of
enthalpy
S = k*ln(w)
w = microstates
k = 1.38 x 10⁻²³ J/K
Entropy (S)
- measure of degree of disorder or randomness in a system
- describes how spread out a systems energy is
An increase in temperature increases the KE, which _________ the entropy.
increases
the particles move faster and energy is dispersed faster and
throughout the system
,Microstates
- number of energetically equivalent arrangements possible for the
system
Macrostate
- set of energetically equivalent microstates
3rd Law of Thermodynamics
- entropy of a pure, perfectly ordered, crystalline substance at
absolute zero is zero
- at ab. zero there is no thermal energy to cause particles in solid
to move
S = k*ln(l)
Equation for ∆S° rxn =
∆S° rxn = Σm[S°(products)] - Σn[S°(reactants)]
Equation for ∆S univ =
∆S univ = ∆S sys + ∆S surr
, Isothermal Processes
(no temp change in surroundings)
- entropy change of the surr is related to the thermal energy
change of the sys
∆S surr = -q sys / T = -∆H sys / T
The effect of entropy change of sys on entropy of surr is smaller at
_________ temps than ______ temps.
higher
lower
At __________ temps surr have higher KE and the release of heat energy by
the sys will increase that KE by a lower % than at ____ temps.
higher
lower
In an exothermic rxn, the
q sys ___ 0.
< or >
>
Gibb's Free Energy, G
- state function defined in terms of the enthalpy, entropy, and temp
of the system, and used to determine if a process is spontaneous
T∆S univ = ∆H sys + T∆S sys
G = H - TS
∆G° = ∆H° - T∆S°
ACTUAL EXAM 2026/2027 AND HIGH YIELD PRACTICE
QUESTIONS COMPLETE ACCURATE EXAM APPROVED
QUESTIONS AND CORRECT VERIFIED SOLUTIONS (100%
CORRECT VERIFIED ANSWERS) CURRENTLY UPDATED
VERSION 2026 EDITION |GUARANTEED PASS
1st Law of Thermodynamics
- total energy of the universe is constant; energy is neither created
not destroyed, but it can be transferred
2nd Law of Thermodynamics
- spontaneous processes always result in an overall increase of
enthalpy
S = k*ln(w)
w = microstates
k = 1.38 x 10⁻²³ J/K
Entropy (S)
- measure of degree of disorder or randomness in a system
- describes how spread out a systems energy is
An increase in temperature increases the KE, which _________ the entropy.
increases
the particles move faster and energy is dispersed faster and
throughout the system
,Microstates
- number of energetically equivalent arrangements possible for the
system
Macrostate
- set of energetically equivalent microstates
3rd Law of Thermodynamics
- entropy of a pure, perfectly ordered, crystalline substance at
absolute zero is zero
- at ab. zero there is no thermal energy to cause particles in solid
to move
S = k*ln(l)
Equation for ∆S° rxn =
∆S° rxn = Σm[S°(products)] - Σn[S°(reactants)]
Equation for ∆S univ =
∆S univ = ∆S sys + ∆S surr
, Isothermal Processes
(no temp change in surroundings)
- entropy change of the surr is related to the thermal energy
change of the sys
∆S surr = -q sys / T = -∆H sys / T
The effect of entropy change of sys on entropy of surr is smaller at
_________ temps than ______ temps.
higher
lower
At __________ temps surr have higher KE and the release of heat energy by
the sys will increase that KE by a lower % than at ____ temps.
higher
lower
In an exothermic rxn, the
q sys ___ 0.
< or >
>
Gibb's Free Energy, G
- state function defined in terms of the enthalpy, entropy, and temp
of the system, and used to determine if a process is spontaneous
T∆S univ = ∆H sys + T∆S sys
G = H - TS
∆G° = ∆H° - T∆S°
