1.
2.
3.
4.
5.
Determine the pH of a 0.100 M NaCN solution. Kb (CN−) = 2.0 × 10−5
A. 6.85
C.
10.42
B. 8.47
D.
11.15
Which one of the following aqueous solutions has pH < 7.0?
A. CH3NH3Br
C.
KNO3
B. NaC2H3O2
D.
LiClO
Consider the polyprotic acid H2C2O4 (oxalic acid). Which of the following is true?
A.
Ka1 > Ka2
C.
Ka1 = Ka2
B.
Ka1 < Ka2
D.
Not enough information is given to provide an answer.
Which lists the binary compounds in order of increasing acidity?
A.
HI < H2Se < H2S < LiH
C.
LiH < H2S < H2Se < HI
B.
LiH < HI < H2Se < H2S
D.
H2S < H2Se < LiH < HI
Which of the following is the strongest oxyacid?
A.
HClO
C.
HClO3
B.
HClO2
D.
HClO4
6.
7.
Which one of the following is the strongest Lewis acid?
A. Cr6+
C.
CN−
B. Cr3+
D.
AsH3
Which statement is true for the reaction below?
Al3+(aq) + 6 H2O(l) ⇌ Al(H2O)63+(aq)
8.
9.
A.
H2O is a Lewis acid; it is an electron pair donor.
B.
H2O is a Lewis acid; it is an electron pair acceptor.
C.
Al3+ is a Lewis acid; it is an electron pair acceptor.
D.
Al3+ is a Lewis base; it is an electron pair donor.
Which one of the following combinations acts as a buffer?
A.
0.20 M HBr and 0.10 M Ba(OH)2
C.
0.20 M NaCN and 0.20 M HC2H3O2 (acetic acid)
B.
0.25 M NH3 and 0.30 M (CH3)2NH
D.
0.45 M HCHO2 (formic acid) and 0.50 M NaCHO2
Determine the pH of a buffer solution that is 0.050 M acetic acid (HC2H3O2) and 0.150 M sodium acetate
(NaC2H3O2). Ka (HC2H3O2) = 1.8 × 10−5
A.
3.21
C.
4.74
B.
4.33
D.
5.22
10.
Which one of the following titrations has pH > 7.0 at the equivalence point?
A. Na2CO3 titrated with HBr
C. C6H5NH2 (aniline) titrated with HCl
B. HNO3 titrated with NaOH
11.
12.
13.
D. HC4H7O2 (butyric acid) titrated with KOH
What is the pH of a buffer solution containing 0.450 M hydroxylamine (HONH2) and 0.350 M
hydroxylammonium chloride (HONH3Cl)? Kb (HONH2) = 1.1 × 10−8
A. 2.43
C.
6.15
B. 4.18
D.
8.96
The highest pH for an effective buffer is defined as pH = pKa + 1. At this point, which of the following is
true?
A.
The concentration of the conjugate base is 10 × the concentration of the weak acid.
B.
The concentration of the conjugate base is double the concentration of the weak acid.
C.
The concentration of the conjugate base is the same as the concentration of the weak acid.
D.
The concentration of the conjugate base is 0.1 × the concentration of the weak acid.
Which buffer has the greatest capacity for neutralizing added OH−?
A. 0.100 M HF and 0.100 M NaF
C.
0.100 M HF and 0.500 M NaF
B. 0.500 M HF and 0.100 M NaF
D.
0.010 M HF and 0.010 M NaF
14.
15.
16.
The plot shows the titration of a strong acid with a strong
base. At the equivalence point, which of the following is
true?
A.
mol H3O+ = mol OH−
C.
mol H3O+ < mol OH−
B.
mol H3O+ > mol OH−
D.
The resulting solution is a buffer.
A 100-mL buffer solution contains 0.350 M lactic acid (HC3H5O3) and 0.250 M sodium lactate
(NaC3H5O3). What is the pH when 5.00 mL of 3.00 M KOH has been added? pKa (HC3H5O3) = 3.85
A.
2.36
C.
4.15
B.
3.85
D.
8.56
What is the pH after mixing 30.0 mL of 0.100 M HCl with 25.0 mL of 0.100 M NaCN?
Kb (CN−) = 2.0 × 10−5
A.
4.25
C.
2.04
B.
3.22
D.
1.56
17.
18.
19.
20.
21.
One type of indicator is a weak acid that is a different color than its conjugate base. Over which pH range
will the indicator change color?
A. pH = pKa (indicator) ± 1
C.
pH = pKa (indicator) ± 0.1
B. pH = pKa (indicator) ± 10
D.
pH = pKa (indicator)
Which of the following salts is the most soluble in pure water?
A. CdCO3, Ksp = 1.0 × 10−12
C.
BaCO3, Ksp = 2.6 × 10−9
B. FeCO3, Ksp = 3.1 × 10−11
D.
MgCO3, Ksp = 6.8 × 10−6
Determine the molar solubility of BaF2 in pure water. Ksp (BaF2) = 2.45 × 10−5
A.
0.561 M
C.
5.36 × 10−3 M
B.
1.83 × 10−2 M
D.
4.43 × 10−4 M
In which aqueous solution is SrSO4(s) most soluble? Ksp (SrSO4) = 3.4 × 10−7
A. 0.10 M Sr(NO3)2
C.
0.10 M Na2SO4
B. 0.10 M KNO3
D.
0.10 M H2SO4
A. increasing pH.
C.
decreasing pOH.
B. decreasing pH.
D.
increasing concentration of Mg2+(aq).
The solubility of Mg(OH)2 increases with
22.
23.
Will a precipitate of CaC2O4 form when two solutions are mixed such that the final concentrations are
5.0  103 M Ca(NO3)2 and 2.0  102 M K2C2O4? Ksp (CaC2O4)= 2.32 × 10−9
A. Yes, because Q > Ksp
C.
No, because Q < Ksp
B. Yes, because Q < Ksp
D.
No, because Q = Ksp
A solution contains 0.010 M CO32− and 0.010 M S2−. Which compound precipitates first and what
concentration of Fe2+ is required to begin precipitation?
Ksp (FeS) = 3.07 × 10−11
Ksp (FeCO3) = 3.72 × 10−19
A. FeS precipitates first when [Fe2+] = 6.10 × 10−11 M
B. FeS precipitates first when [Fe2+] = 3.07 × 10−9 M
C. FeCO3 precipitates first when [Fe2+] = 3.72 × 10−17 M
D. FeCO3 precipitates first when [Fe2+] = 5.54 × 10−11 M
24.
Which statement is true?
A. Spontaneous reactions only occur with ongoing outside intervention.
B. Nonspontaneous reactions are impossible.
C. Thermodynamically spontaneous reactions must also be kinetically fast.
D. If a process is spontaneous in one direction, it must be nonspontaneous in the opposite direction.
25.
26.
The Second Law of Thermodynamics states that an endothermic process will proceed spontaneously as
long as
A.
ΔSuniverse < 0
C.
ΔSuniverse > 0
B.
ΔSuniverse = 0
D.
Spontaneity cannot be determined from ΔSuniverse.
According to the Second Law of Thermodynamics, heat must flow from the
water to the ice because it results in
A. more dispersal of heat, thereby increasing the entropy of the universe.
B. less dispersal of heat, thereby increasing the entropy of the universe.
C. more dispersal of heat, thereby decreasing the entropy of the universe.
D. less dispersal of heat, thereby decreasing the entropy of the universe.
27.
Predict the signs of ΔS for the following reactions:
1) CO2(g)  CO2(s)
2) 2 N2(g) + O2(g)  2 N2O(g)
A. 1) ΔS is positive; 2) ΔS is positive
C.
1) ΔS is positive; 2) ΔS is negative
B. 1) ΔS is negative; 2) ΔS is negative
D.
1) ΔS is negative; 2) ΔS is positive
28.
29.
Which chart best represents the spontaneous condensation of H2O(g) to H2O(l)?
A.
C.
B.
D.
Determine the entropy change in the surroundings for the following reaction at 25.0 °C:
4 NH3(g) + 5 O2(g)  4 NO(g) + 6 H2O(g)
30.
ΔHrxn = −906 kJ
A. +6.95 kJ/K
C.
–1.14 kJ/K
B. +3.04 kJ/K
D.
−2.82 kJ/K
A 0.1255 g sample of an unknown monoprotic acid was titrated with 0.0450 M KOH. The equivalence
point occurs at 20.20 mL. What is the molar mass of the unknown acid?
A. 122 g/mol
C.
148 g/mol
B. 138 g/mol
D.
180. g/mol
Answer Key:
1. D
2. A
3. A
4. C
5. D
6. A
7. C
8. D
9. D
10. D
11. C
12. A
13. B
14. A
15. C
16. C
17. A
18. D
19. B
20. B
21. B
22. A
23. C
24. D
25. C
26. A
27. B
28. B
29. B
30. B