Chapter 19
50.0 mL 0.217 M hydrazoic acid, HN3, (Ka = 2.6 × 10‒5) titrated with 0.183 M NaOH. pH before addition of NaOH = ?
A. 2.62
B. 8.79
C. 12.21
D. 4.59
E. 7.00
A process has delta S > 0 at 25°C. Therefore –
A. It is exothermic.
B. It is endothermic.
C. It is spontaneous at 25°C.
D. It will go rapidly to equilibrium
C. It is spontaneous at 25°C.
For the reaction
CO(g) + H2O(g) -> CO2(g) + H2(g)
ΔS will be
A. Positive
B. Close to Zero
C. Negative
I-(aq) + NO3-(aq) NO(g) + I2(s)
(acidic solution)
When balanced, the coefficient on the iodide ion will be
A. 2
B. 3
C. 6
D. 8
Which CAN’T make H2 from acid? (need table)
A. Cr
B. Li
C. Fe
D. Cu
E. Zn
D. Cu
50.0 mL 0.217 M hydrazoic acid, HN3, (Ka = 2.6 × 10‒5) titrated with 0.183 M NaOH. pH after addition of 29.7 mL NaOH = ?
A. 2.61
B. 8.79
C. 12.21
D. 4.59
E. 7.00
Predict ΔS for:
C2H5OH(g)(350 K, 500 torr) -> C2H5OH(g)(350 K, 250 torr)
A. Positive
B. Zero
C. Negative
D. Impossible to predict
2 Cu(s) + ½ O2(g) -> Cu2O(s) ΔS = ?
S in J/(mol K): Cu(s), 33.1;
O2(g), 205.0; Cu2O(s), 93.1
A. -60.0 J/K
B. -75.6 J/K
C. -93.1 J/K
D. -145.0 J/K
E. -205.0 J/K
For the skeleton reaction:
Cl2(g) + Cr(s) 2 Cl-(aq) + Cr3+(aq)
Which is correct?
A. Ecell = 2.10 V, spontaneous
B. Ecell = 0.62 V, spontaneous
C. Ecell = -2.10 V, nonspontaneous
D. Ecell = -0.62 V, nonspontaneous
A. Ecell = 2.10 V, spontaneous
Which CAN get rid of Zn2+ from solution? (need table)
A. Na
B. Fe
C. Cr
D. Cu
E. Ag
A. Na
The solubility of silver chromate, Ag2CrO4, is 8.7x10-5 M. What is the value of Ksp?
A. 8.7x10-5
B. 7.6x10-9
C. 2.6x10-12
D. 6.6x10-13
Predict ΔS for:
Cu(s)(350C, 2.5 atm) -> Cu(s)(450C, 2.5 atm)
A. Positive
B. Zero
C. Negative
D. Impossible to predict
ΔH(sys) = 50 kJ at 25C.
ΔS(surr) = ?
A. 2.0 kJ/K
B. -2.0 kJ/K
C. 168 J/K
D. -168 J/K
Cu2+(aq) + Fe(s) Cu(s) + Fe2+(aq)
Cu/Cu2+ E = 0.34V
Fe/Fe2+ E = -0.44V
Is the reaction spontaneous as written?
A. 1. yes
B. 2. no
C. 3. insufficient information
A. 1. yes
Cell from Ni/Ni2+ (E° = −0.25 V) and
Co/Co2+ (E° = −0.28 V) half-cells.
If [Ni2+] = 0.80 M, [Co2+] = 0.20 M,
what is the cell potential = ?
A. 0.01 V
B. 0.03 V
C. 0.05 V
D. 0.07 V
C. 0.05 V
For PbCl2, Ksp = 1.7x10-5. If 100 mL 0.040 M NaCl and 100 mL 0.040 M Pb(NO3)2 are combined, will a precipitate form?
A. Yes
B. No
C. Insufficient information
For the reaction Pb(s) + Cl2(g) -> PbCl2(s) ΔS will be:
A. Positive
B. Zero
C. Negative
D. Impossible to predict
For a certain reaction, ΔH < 0 and ΔS > 0. The reaction will be spontaneous at
A. high T only
B. low T only
C. any T
D. no T
Reduction Potentials (Cu/Cu2+ reference):
Ag/Ag+ half-cell E = +0.438V
Pb/Pb2+ half-cell E = -0.429 V
Make a voltaic cell from Pb/Pb2+ and Ag/Ag+ half-cells. The positive electrode is _?_, and E°cell = _?_.
A. Ag, 0.867 V
B. Ag, 0.009 V
C. Pb, 0.867 V
D. Pb, 0.009 V
A. Ag, 0.867 V
If current = 0.750 ampere, how long does it take to pass those 215 coulombs through the molten salt?
A. 81 s
B. 144 s
C. 161 s
D. 287 s
D. 287 s
The solution being titrated contains a
A. Monoprotic strong acid
B. Monoprotic weak acid
C. Diprotic weak acid
D. Dibasic weak base
E. Monobasic weak base
F. Monobasic strong base
Which is always true for an exothermic process?
A. qsys > 0, delta Ssurr < 0
B. qsys < 0, delta Ssurr > 0
C. qsys < 0, delta Ssurr < 0
D. qsys > 0, dealt Ssurr > 0
E. w < 0
B. qsys < 0, delta Ssurr > 0
What is the 2nd law of thermodynamics?
A. S = k lnW
B. ΔEsys = 0
C. ΔEuniv = 0
D. ΔSsys > 0
E. ΔSuniv > 0
E. ΔSuniv > 0
Mn(s)|Mn2+(aq)||Cd2+(aq)|Cd(s)
What is the reaction equation?
A. Mn(s) + Mn2+(aq) -> Cd2+(aq) + Cd(s)
B. Cd2+(aq) + Cd(s) -> Mn(s) + Mn2+(aq)
C. Mn(s) + Cd2+(aq) -> Mn2+(aq) + Cd(s)
D. Mn2+(aq) + Cd(s) -> Mn(s) + Cd2+(aq)
C. Mn(s) + Cd2+(aq) -> Mn2+(aq) + Cd(s)
Voltaic cell from two Al/Al3+ half-cells. In one, [Al3+] = 0.050 M. In the other, [Al3+] = 1.25 M. Ecell = ?
A. 0.083 V
B. -0.083 V
C. 0.028 V
D. -0.028 V
E. 0.062 V
C. 0.028 V