CHEM 116 STUDY GUIDE EXAM EVALUATION QUESTIONS
WITH ANSWERS 2025/2026
Which one of the following processes produces a decrease in the entropy of the
system? - freezing water to form ice
DeltaS is positive for the reaction - 2SO3(g) -> 2SO2(g) + O2(g)
Which reaction produces a decrease in the entropy of the system? - 2H2(g) + O2(g) ->
2H2O (l)
Which reaction produces an increase in the entropy of the system? - CO2(s) -> CO2(g)
Which of the following processes produces a decrease of the entropy of the system? -
dissolving oxygen in water
DeltaS is negative for the reaction - 2SO2(g) + O2(g) -> 2SO3(g)
DeltaS is positive for the reaction - 2H2O(g) -> 2H2(g) + O2(g)
DeltaS is negative for the reaction - Mg(NO3)2(aq) + 2NaOH(aq) -> Mg(OH)2(s) +
2NaNO2(aq)
Which one of the following correctly indicates the relationshop between the entropy of a
system and the number of different arrangement, W, in the system? - S = k lnW
The entropy change accompanying any process is given by the equation - DeltaS = k
ln(Wfinal/Winitial)
Of the following, the entropy of gaseous ___ is the largest at 25 C and 1 atm... - C2H6
Of the following, the entropy of ___ is the largest. - HI(g)
For an isothermal process, the entropy change of the surroundings is given by the
equation - DeltaS = -qsys/T
The standard Gibbs free energy of formation of ___ is zero. a) H2O(l) b) O(g) c)H2(g) -
C only - H2(g)
The standard Gibbs free energy of formation of ___ is zero. a) H2O(l) b) Na(s) c)H2(g) -
B and C - b) Na(s) c)H2(g)
The standard Gibbs free energy of formation of ___ is zero. a) Al(s) b) Br2(l) c) Hg(l) -
All - a) Al(s) b) Br2(l) c) Hg(l)
, DeltaH is +137 kJ/mol and DeltaS is +120 J/Kmol. This reaction is ___. - spontaneous
only at high temperature
A reaction that is NOT spontaneous at low temperature can become spontaneous at
hight temperature if DeltaH is___ and DeltaS is ____. - Positive, Positive
For a reaction to be spontaneous under standard conditions at all temperatures, the
signs of DeltaH and DeltaS must be ___ and ___, respectively. - Negative, Positive
With thermodynamics, one cannot determine ____. - the speed of a reaction.
If DeltaG for a reaction is greater than zero, then ____. - K < 1
If DeltaG for a reacton s less than zero, then - K > 1
T/F The melting of a substance at its melting point is an isothermal process. - True
The vaporization of a substance at its boiling point is an isothermal process. - True
The quantity of energy gained by a system equals the quantity of energy gained by its
surroundings. - False
The entropy of a pure crystalline substance at 0 C is zero. - False
The more negative DeltaG is for a given reaction, the larger the value of the
corresponding equilibrium constant, K. - True
The gain of electrons by an element I called - Reduction
____ is reduced in Cr2O7+6S2O3+14H -> 2Cr +3S4O6+7H2O - Cr 6+
____ is the oxisizing agent in Cr2O7+6S2O3+14H -> 2Cr +3S4O6+7H2O - Cr2O7 2-
Which substance is serving as the reducing agent in the following 14H+Cr2O7+3Ni ->
3Ni+2Cr+7H2O - Ni
Which substance is the reducing agent in the reaction Pb+PbO2+2H2So4 ->
2PbSO4+2H2O - Pb
What is the oxidation number of chromium in Cr2O7 ion? - +6
What is the oxidation number of potassium in KMnO4? - +1
What is the oxidation number of manganese in the MnO4 1- ion? - +7
What is the oxidation number of manganese in MnO2? - +4
WITH ANSWERS 2025/2026
Which one of the following processes produces a decrease in the entropy of the
system? - freezing water to form ice
DeltaS is positive for the reaction - 2SO3(g) -> 2SO2(g) + O2(g)
Which reaction produces a decrease in the entropy of the system? - 2H2(g) + O2(g) ->
2H2O (l)
Which reaction produces an increase in the entropy of the system? - CO2(s) -> CO2(g)
Which of the following processes produces a decrease of the entropy of the system? -
dissolving oxygen in water
DeltaS is negative for the reaction - 2SO2(g) + O2(g) -> 2SO3(g)
DeltaS is positive for the reaction - 2H2O(g) -> 2H2(g) + O2(g)
DeltaS is negative for the reaction - Mg(NO3)2(aq) + 2NaOH(aq) -> Mg(OH)2(s) +
2NaNO2(aq)
Which one of the following correctly indicates the relationshop between the entropy of a
system and the number of different arrangement, W, in the system? - S = k lnW
The entropy change accompanying any process is given by the equation - DeltaS = k
ln(Wfinal/Winitial)
Of the following, the entropy of gaseous ___ is the largest at 25 C and 1 atm... - C2H6
Of the following, the entropy of ___ is the largest. - HI(g)
For an isothermal process, the entropy change of the surroundings is given by the
equation - DeltaS = -qsys/T
The standard Gibbs free energy of formation of ___ is zero. a) H2O(l) b) O(g) c)H2(g) -
C only - H2(g)
The standard Gibbs free energy of formation of ___ is zero. a) H2O(l) b) Na(s) c)H2(g) -
B and C - b) Na(s) c)H2(g)
The standard Gibbs free energy of formation of ___ is zero. a) Al(s) b) Br2(l) c) Hg(l) -
All - a) Al(s) b) Br2(l) c) Hg(l)
, DeltaH is +137 kJ/mol and DeltaS is +120 J/Kmol. This reaction is ___. - spontaneous
only at high temperature
A reaction that is NOT spontaneous at low temperature can become spontaneous at
hight temperature if DeltaH is___ and DeltaS is ____. - Positive, Positive
For a reaction to be spontaneous under standard conditions at all temperatures, the
signs of DeltaH and DeltaS must be ___ and ___, respectively. - Negative, Positive
With thermodynamics, one cannot determine ____. - the speed of a reaction.
If DeltaG for a reaction is greater than zero, then ____. - K < 1
If DeltaG for a reacton s less than zero, then - K > 1
T/F The melting of a substance at its melting point is an isothermal process. - True
The vaporization of a substance at its boiling point is an isothermal process. - True
The quantity of energy gained by a system equals the quantity of energy gained by its
surroundings. - False
The entropy of a pure crystalline substance at 0 C is zero. - False
The more negative DeltaG is for a given reaction, the larger the value of the
corresponding equilibrium constant, K. - True
The gain of electrons by an element I called - Reduction
____ is reduced in Cr2O7+6S2O3+14H -> 2Cr +3S4O6+7H2O - Cr 6+
____ is the oxisizing agent in Cr2O7+6S2O3+14H -> 2Cr +3S4O6+7H2O - Cr2O7 2-
Which substance is serving as the reducing agent in the following 14H+Cr2O7+3Ni ->
3Ni+2Cr+7H2O - Ni
Which substance is the reducing agent in the reaction Pb+PbO2+2H2So4 ->
2PbSO4+2H2O - Pb
What is the oxidation number of chromium in Cr2O7 ion? - +6
What is the oxidation number of potassium in KMnO4? - +1
What is the oxidation number of manganese in the MnO4 1- ion? - +7
What is the oxidation number of manganese in MnO2? - +4
