R = 8.314 × 10–3 kJ·mol–1·K–1
F = 96485 C·mol–1
 
ΔSsurr = -qsys/T
(at const. T)
qsys = ΔHsys
(at const. P)
ΔGr° = ΔHr° - TΔSr°          
ΔSr° = Σ n Sm°(prod) – Σ n Sm°(react)
ΔHr° = Σ n ΔHf°(prod) – Σ n ΔHf°(react)
ΔGr° = – RT lnK
ΔGr = ΔGr° + RT lnQ
E° = (0.0257/n) lnK
(at 298 K)
E = E° – (0.0257/n) lnQ
(at 298 K)
ΔGr° = – nFEcell°
n = (I t)/F
 



1.
Which of the following should have the greatest molar entropy at 298 K?
A.
Cl2(g)
B.
Cl2(aq)
C.
F2(g)
D.
F2(aq)
E.
All should have the same molar entropy since the temperature is constant.


2.
Predict the sign of ΔSo for the following reaction.
     
A.
ΔSo ≈ 0
B.
ΔSo < 0
C.
ΔSo > 0
D.
ΔSo could be positive or negative depending on the sign of ΔΗo.
E.
More information is needed to make a reasonable prediction.


3.
Which of the following relationships best describes ΔSo for the following reaction.
     
A.
ΔSo > 0
B.
ΔSo ≈ 0
C.
ΔSo < 0
D.
ΔSo = TΔΗo
E.
More information is needed to make a reasonable prediction.


4.
Calculate ΔSo for the reaction 4A(l) + B(g) → 3C(s) + D(g).
Substance
A(l)
B(g)
C(s)
D(g)
S° (J/K⋅mol)
142.1
213.6
94.6
265.4
 
A.
232.8 J/K
B.
4.3 J/K
C.
–4.3 J/K
D.
715.7 J/K
E.
–232.8 J/K


5.
For a given chemical reaction, ΔΗ < 0 and ΔS > 0. Therefore,
A.
The reaction is spontaneous only at high temperatures.
B.
The reaction is spontaneous only at low temperatures.
C.
The reaction is non-spontaneous at all temperatures.
D.
The reaction is spontaneous at all temperatures.


6.
Calculate ΔGo at 298 K for the reaction 2A(s) + B(g) → C(s) + 2D(g).
Substance
A(s)
B(g)
C(s)
D(g)
ΔG°f (kJ/mol at 298 K)
–197.9
38.8
–169.7
73.4
 
A.
–334.1 kJ
B.
62.8 kJ
C.
–62.8 kJ
D.
–255.4 kJ
E.
334.1 kJ


7.
Consider the following thermodynamic data which refer to 298 K.
Substance
SO2(g)
Cl2(g)
SOCl2(g)
Cl2O(g)
ΔH°f (kJ/mol at 298 K)
-296.8
 
–212.5
80.3
ΔG°f (kJ/mol at 298 K)
-300.2
 
–198.3
97.9
S° (J/K⋅mol at 298 K)
248.1
223.0
309.8
266.1
What is the value of ΔG° for the reaction below at 601 K?  
       SO2(g)   +   2Cl2(g)   →   SOCl2(g)   +   Cl2O(g)
A.
199.8 kJ
B.
–199.8 kJ
C.
–235.6 kJ
D.
235.6 kJ
E.
164.6 kJ


8.
Use the following thermodynamic data which refer to 298 K to calculate the normal boiling point of the substance A.         (Note: The normal boiling point is the temperature at which the process   A(l) → A(g)   reaches equilibrium at 1.0 atm.)
Substance
A(l)
A(g)
ΔΗ°f (kJ/mol)
–186.6
–126.3
S° (J/K⋅mol)
77.0
225.7
 
A.
360.2 K
B.
490.8 K
C.
405.5 K
D.
256.3 K
E.
532.4 K


9.
The solubility product of the ionic compound MA(s) is Ksp = 3.1×10–12 at 25oC. What is ΔGo for the following reaction at this temperature?
        MA(s) ↔ M+(aq) + A–(aq)
A.
72.5 kJ
B.
65.7 kJ
C.
82.1 kJ
D.
88.6 kJ
E.
40.0 kJ


10.
Consider the following redox equation
        I2(s)   +   NO3–(aq)   →   IO3–(aq)   +   NO2(g)           (acidic solution)
When the equation is balanced with smallest whole number coefficients, what is the coefficient of nitrogen dioxide?
A.
10
B.
4
C.
6
D.
8
E.
12


11.
Which one of the following statements about electrochemical cells is correct?
A.
In the external wire electrons travel from cathode to anode.
B.
Oxidation occurs at the anode of both galvanic and electrolytic cells.
C.
The free energy change is positive for a voltaic cell.
D.
The anode is labeled as positive (+) in a voltaic cell but negative (-) in an electrolytic cell.
E.
None of the above statements is correct.


12.
A galvanic cell has the following notation:
        Fe(s) | Fe2+(aq) || Co3+(aq), Co2+(aq) | Pt(s)
Which of the following equations correctly represents the overall cell reaction?
A.
Fe(s)   +   Co2+(aq)   →   Fe2+(aq)   +   Co3+(aq)
B.
Fe2+(aq)   +   2Co3+(aq)   →   Fe(s)   +   2Co2+(aq)
C.
Fe(s)   +   2Co3+(aq)   →   Fe2+(aq)   +   2Co2+(aq)
D.
Fe2+(aq)   +   Co2+(aq)   →   Fe(s)   +   Co3+(aq)
E.
Fe(s)   +   Co3+(aq)   →   Fe2+(aq)   +   Co2+(aq)


13.
What is the Eocell for the spontaneous reaction resulting from the combination of half-reactions (4) and (1) below?
   (1)     HgO(s)   +   H2O(l)   +   2e–   ↔   Hg(l)   +   2OH–(aq)                    E° = 0.098 V
   (2)     Zn(OH)2(s)   +   2e–   ↔   Zn(s)   +   2OH–(aq)                                 E° = -1.250 V
   (3)     Ag2O(s)   +   H2O(l)   +   2e–   ↔   Ag(s)   +   2OH–(aq)                  E° = 0.342 V
   (4)     B(OH)3(aq)   +   7H+(aq)   +   8e– ↔   BH4–(aq)   +   3H2O(l)        E° = -0.481 V
A.
–0.579 V
B.
–0.383 V
C.
0.383 V
D.
0.192 V
E.
0.579 V


14.
Examine the table of standard reduction potentials attached to your test and determine which of the following species is the strongest oxidizing agent?
A.
NO3–(aq)
B.
I2(s)
C.
Ni(s)
D.
Ce4+(aq)
E.
Cu+(aq)


15.
Use the table of standard reduction potentials attached to your test to calculate Eocell for the following reaction and determine if it is spontaneous at standard conditions.
        Mn2+(aq)   +   Mg(s)   →   Mg2+(aq)   +   Mn(s)
A.
Eocell = 1.19 V, spontaneous
B.
Eocell = –1.19 V, non-spontaneous
C.
Eocell = 1.19 V, non-spontaneous
D.
Eocell = –1.19 V, spontaneous
E.
Eocell = –3.55 V, non-spontaneous


16.
If Eocell = –0.74 V for the reaction below at 25oC, what is the value of the equilibrium constant at this temperature.
        Mn2+(aq)   +   Fe(s)   ↔   Fe2+(aq)   +   Mn(s)
A.
9.8e–1
B.
9.8e–26
C.
3.1e–13
D.
1.9e0
E.
1.0e25


17.
A galvanic cell consists of an Au/Au3+ electrode (Eo = +1.50 V) and a Cu/Cu2+ electrode (Eo = +0.34 V). Calculate the cell potential, Ecell, at 25oC if [Au3+] = 3.6×10–4 M and [Cu2+] = 6.3×10–2 M.
A.
1.16 V
B.
1.08 V
C.
1.13 V
D.
1.05 V
E.
1.02 V


18.
Which, if any, of the following three metals could be used as sacrificial anodes for protection of a metal with E° = 0.18 V? (All E° values refer to the M3+/M half-cell reactions.)
        (1)   gold, Au, E° = +1.50 V
        (2)   chromium, Cr, E° = -0.74 V
        (3)   aluminum, Al, E° = -1.66 V
A.
Only (3) could be used.
B.
None of them could be used.
C.
All three of them could be used.
D.
Only (2) and (3) could be used.
E.
Only (1) and (2) can be used.


19.
Which, if any, of the following two elements can be isolated by electrolysis of the the aqueous salt shown?
        (1)   Ni from NiSO4(aq)
        (2)   F2 from NaF(aq)
A.
Both (1) and (2) can be isolated.
B.
Neither (1) nor (2) can be isolated.
C.
(1) can be isolated but (2) can not be isolated.
D.
(1) can not be isolated but (2) can be isolated.


20.
What mass of copper (molar mass 63.55 g/mol) will be deposited at the cathode when 23.8 A are passed through a CuSO4 solution for 60.0 minutes?
A.
28.2 g
B.
25.6 g
C.
35.1 g
D.
21.7 g
E.
43.2 g


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