Supplemental Instruction
Iowa State University / Leader: / Lindsey
Course: / CHEM 178
Instructor: / Vela-Becerra
Date: / 3/10/14
1. TRUE/FALSE The Hendserson-Hasslebach equation shows for a buffer solution that changing the total volume of the solution does not change the pH.
2. Which o the following solutions is a buffer?
a. 0.1 M HCl and 0.1 M NaCl
b. 0.1 M NH4Cl and 0.1 M NaCl
c. 0.1 M NH4Cl and 0.1M CH3COOH
d. 0.1 M NH3 and 0.1 M NH4Cl
3. What is the solubility of AgCl in mol/L in a 0.2 M MgCl2 solution?
Ksp= 1.8x10-10 for AgCl
a. 1.3x10-5
b. 1.8x10-10
c. 4.5x10-9
d. 3.8x10-7
4. What is the equivalence point pH of the solution formed by the titration of 50 mL of 0.15 M CH3COOH using 25 mL of 0.3 M NaOH?
a. 3.22
b. 4.53
c. 7.00
d. 8.26
e. 8.88
5. If x equals the solubility of Ag2CO3, then how is the value of Ksp for Ag2CO3 related to the value of x?
a. 4x3
b. x3
c. 2x3
d. x2
e. 2x2
6. The net ionic equation describing the reaction of added NaOH to a buffer solution containing HCO3- and CO32- is
a. OH- + CO32-HCO43-
b. OH- + HCO3-H2O + CO32-
c. CO32-+ 2Na+ Na2CO3
d. Na+ + HCO3- NaHCO3
e. Na+ + H2O H+ + NaOH
7. Which one of the following will increase the ionization/dissociation of a weak acid H2SO3?
a. Adding water
b. Evaporating water
c. All of the above
d. None of the above
8. Which of these conjugate acid-base pairs will NOT function as a buffer?
a. CH3COOH and CH3COO-
b. HCl and Cl-
c. HCO3- and CO32-
d. All of the above will function as a buffer
9. What is the equivalence point pH of the solution formed by the titration of 50 mL 0f 0.15 M HCl using 50 mL 0.15 M NaOH?
a. 1
b. 4
c. 7
d. 9
e. 10
10. Over what approximate pH range would a buffer be useful if the pKa of the acid is 2.7?
a. 0-14
b. 2.7-3.7
c. 2.0 – 3.0
d. 1.7-3.7
11. Which of the following is a Lewis acid, but not a bronsted acid?
a. HCl
b. BBr3
c. NH3
d. KOH
e. CH4
12. Which one of the following binary compounds would you expect to be the most acidic?
a. NaH
b. CH4
c. SnH4
d. H2O
e. H2S
13. What is the pH of a 0.03 M solution of Ba(OH)2?
a. 1.52
b. 12.48
c. 1.22
d. 12.78
e. 0.03
14. TRUE/FALSE NH4OH is an oxyacid.
15. The aqueous solution of KClO4 is
a. Acidic
b. Basic
c. Neutral
16. Which of the following 0.1 M solutions has the smallest pH?
a. NH4Cl
b. NaNO3
c. BaI2
d. NH3
e. Na2CO3
17. The pH of a 0.15 M weak base B is 9.25. What is Kb for B?
a. 1.3x10-10
b. 2.11x10-9
c. 6.25x10-8
d. 2.39x10-7
e. 6.92x10-3
18. Ag+ is carefully and slowly added to a solution containing Cl–, Br–, and I–. Which compound would precipitate out of solution first?
a. AgCl (Ksp=1.8x10-10)
b. AgBr (Ksp=5x10-13)
c. AgI (Ksp=8.3x10-17)
d. All simultaneously precipitate
19. A Lewis acid is a
a. Electron pair receptor
b. Electron pair donor
c. All of the above
d. None of the above
20. What is the pH of a 0.15 M HCl solution at the start of its titration with 0.15 M NaOH?
a. 0.15
b. -0.15
c. 0.82
d. -0.82
e. 13.2
21. Which occur(s) when HCl is added to an aqueous buffer solution containing ammonia and ammonium chloride?
a. pH of the solution decreases
b. More NH4+ forms
c. Less NH3 exists
d. Less OH- exists
e. All of the above
22. Term given to the effect when NaCl is added to a saturated solution of AgCl
a. Complex ion
b. Common ion
c. Buffer solution
d. Solubility product
23. What is the formation constant expression for Fe(CN)64-?
a. Kf= [Fe2+][CN-]
b. Kf= [Fe2+][CN-]6
c. Kf=[Fe2+][CN-]6/[Fe(CN)64-]
d. Kf=[Fe(CN)64-]/[Fe2+][CN-]6
e. Kf= [Fe(CN)64-]/[Fe2+][CN-]
24. The solubility of BaCO3 in water is increased by which of the following?
a. Addition of NaOH
b. Addition of HNO3
c. Increasing pH of solution
d. Both a & c
25. Which of the following ions will act as a weak base in water?
a. OH-
b. Cl-
c. NO3-
d. ClO-