1412 Lab Final study guide
Dr. Delgado
I am going to select 25 questions out of these 50.
1. What is the first thing you should do when an accident occurs in the lab?
a. Call the police
b. Call 911
c. Inform your instructor
2. If K>>1 where does the equilibrium lie?
a. left b. right
c. in the middle
d. None of the above
3. If K<<1 where does the equilibrium lie?
a. left
b. right
c. in the middle
d. None of the above
d. All of the above
In the weak acid-strong base titration above (Use it to answer questions 4,5,6,7and 8
CH3COOH (aq) +
NaOH(aq)
CH3COO-(aq) + H2O(l)
4. When does the equivalence point take place (use the chart above to estimate the pH).
a. 12
b. 6
c.9
d. 4
5. How many mL have you used (approximately) in the equivalence point?
a. 16mL b.22mL
c. 5mL
d. None of the above
6. When does pH equal to the pKa?
a. At the equivalence point b. at half the equivalence point
c. Never d. None of the above
7. If the half equivalence point is at pH 4.75 what would be the Ka of the reaction?
a. 6.0 X10 23
b. 1.35 X10 -5
c. 6.022 X10 -23
d. 1.35 X10 5
8. How many mL (approximately) have you used at half the equivalence point?
a. 11mL
b. 8mL
c. 10mL
d. 4mL
9) Which one of the following pairs cannot be mixed together to form a buffer solution?
A) HONH2, HONH3Cl
B) NaCl, HCl
C) RbOH, HF
D) KOH, HNO2
E) H2SO3, KHSO3
10) Which one of the following pairs cannot be mixed together to form a buffer solution?
A) NH3, NH4Cl B) NaC2H3O2, HCl (C2H3O2- = acetate)
C) RbOH, HBr D) KOH, HF E) H3PO4, KH2PO4
11)The Henderson-Hasselbalch equation is __________.
 base 
A) [H+] = Ka +
 acid 
 base 
 acid 
 base 
C) pH = pKa + log
 acid 
 acid 
D) pH = pKa + log
 base 
 acid 
E) pH = log
 base 
B) pH = pKa - log
12) A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration
curve above was obtained. The unknown compound is __________.
A) a strong acid
B) a strong base
C) a weak acid
D) a weak base
E) neither an acid nor a base
13)) What substance is oxidized in the following reaction? Cr2O7 2– + 3 SO3 2– + 8 H+  2 Cr3+ + 3 SO4 2– + 4 H2O
a) Cr2O7 2–
b) SO3 2–
c) H+
d) SO4 2–
14) The gain of electrons in a reaction is called
e) none of the above
a) reduction b) oxidation c) reducing agent
15) What is the oxidation state of P in the phosphate ion, PO43– ?
a) +2
b) +3
c) +5
d) emf
e)SHE
d) +6
16) What is the strongest type of intermolecular force present in CH3Cl?
a.
ion-dipole
b. London-dispersion
c. hydrogen bonding
d. dipole-dipole e. none of the above
17) Choose the molecule or compound that exhibits London dispersion forces as its strongest intermolecular
force. a. Cl2
b. C2H6
c. HF
d. HCl
e.CCl4
18) Which of the following compounds will be most soluble in pentane (C5H12)?
a. CH3CH2CH2CH2CH2
b. C6H6
c. KBr
d. HCl
e. none of these compounds should be soluble in pentane
19) Which one is not a colligative property?
a. vapor pressure lowering
b. osmotic pressure
c. freezing point depression
20) Commercial grade HCl solution are typically 39.0% (by mass) HCl in water. Determine the molality of the
HCl, if the solution has a density of 1.20 g/mL
a. 39.0m
b. 17.5m
c. 6.39m
d. 10.7m
e. 9.44m
21) Determine the freezing point depression of a solution that contains 30.7 g of glycerin (C3H8O3) in 376 g
water. For water Kf=1.86 C/m
a. 0.887 C
b. 1.65C
c. 3.33 C
d. 3.85 C
e. 0.654 C
22) A lab assistant needs to prepare 2000 mL of 0.15 M NaCl. How many grams of NaCl are
required to prepare this solution? a. 18 g
b. 17g
c. 15g
d. 19g e. 20g
23 The type of compound that is most likely to contain an ionic bond is
a)
b)
c)
d)
one that is composed of a metal and a nonmetal
a solid metal
one that is composed of only nonmetals
one that is nonpolar
24. What type of intermolecular force occurs between water molecules?
a) ion-dipole b) dipole-dipole c) London dispersion d) covalent
25. In the gas phase reaction below, if the rate of formation of NO2 is 8.24 X 10–4 M s–1, what is the rate of
disappearance of O2?
4 NH3 + 7 O2 –––> 4 NO2 + 6 H2O
a. 1.44 X 10 +3
b. 8.24 x 10 -4
c. 1.44 X 10 -3
d.8.24 x 10 +4
26.Use the table of data shown below to calculate the value of the rate constant k. The reaction is first order.
time (s) [A] (M)
0
0.124
10.0
0.102
20.0
0.0831
30.0
0.0681
40.0
0.0557
a. 0.0244
b. 0.0200
c. 0.200
d.0.0300
27. The correct units for the rate constant k in the rate law Rate = k[A]2[B] are
a) M s–1
b) M–1 s–1
c) M–2 s–1
d) M–1 s–2
28. The rate law for the aqueous reaction H2SeO3 + 6 I– + 4 H+ –––> Se + 2 I3+ 3 H2O is
Rate = k[H2SeO3][I–]3[H+]2. By what factor will the rate increase if we double the concentrations ofall three reactants?
a) 8
b) 32
c) 64
d) 128
29. Given the rate data below for the reaction 2A + 3B–––> Products, what is the rate law for this reaction?
Exp. [A],
1 0.100
2 0.200
3 0.100
M [B],
0.100
0.100
0.200
a) Rate = k[A][B]
M Rate, M sec–1
4.0 X 10–5
1.6 X 10–4
8.0 X 10–5
b) Rate = k[A]2[B]
c) Rate = k[A]2[B]2
d) Rate = k[A][B]2
30. The equilibrium constant Kp for reaction (1) has a value of 0.112. What is the value of the equilibrium constant for
reaction (2) ?
(1) SO2 (g) + 1/2 O2(g)
SO3 (g) Kp = 0.112
(2) 2 SO3 (g)
2 SO2 (g) + O2 (g) Kp = ?
a) 0.512
b) 2.24
c) 44.2
d) 79.7
31. Write the equilibrium constant expression for the reaction 3 Fe (s) + 4 H2O (g)
a) Keq = [CO (g)] / [CO2 (g)][H2 (g)]
c) Keq = [O2 (g)]6 / [CO2 (g)]6
Fe3O4 (s) + 4 H2 (g)
b) Keq = [CO2 (g)]2 / [CO (g)]2
d) Keq = [H2 (g)]4 / [H2O (g)]4
32. Assuming that the following apply to elementary reactions, what is the molecularity of ?
A + B –––> C
a. Uni-molecular
b. bimolecular
c. termolecular
d. multi-molecular
33. Assuming that the following apply to elementary reactions, what is the molecularity of ? Rate = k[A][B]2
a. Uni-molecular
b. bimolecular
c. termolecular
d. multi-molecular
34. Knowing that Ka for acetic acid = 1.8 X 10-5, calculate Go for the dissociation of this substance in
aqueous solution at 25oC. a) 27.1 J/mole b) -27.1 kJ/mol c)27.1 kJ/mole d) -27.1 J/mole e) none of the
above
35. Ammonia is a __________.
A) weak acid
B) strong base
C) weak base
D) strong acid
E) salt
36. What is the conjugate acid of NH3?
A) NH3
B) NH2+
C) NH3+
D) NH4+
E) NH4OH
37. What is the conjugate acid of CO3-2?
A) CO2-2
B) HCO2-2
C) H2CO3
D) HCO3E) none of the above
38) The conjugate base of HSO4- is __________.
A) OHB) H2SO4
C) SO42D) HSO4+
E) H3SO4+
39)Which is a conjugate pair?
a) LiF and NaF
b) HF and HCl
c) HF and KF
40)Which of the following is a strong base?
a) KOH
b) KF
c) KC2H3O2
d) HNO3
d) HNO2 and HNO3
41)Which of the following is a strong acid?
a) HClO2
c) HNO2
c) HClO4
d) H2SO3
42) Which of the following is a strong base?
a) KOH
b) KF
c) KC2H3O2
d) HNO3
43) An unknown solution of H3PO4 was titrated with 0.100 M NaOH. If 50.0 mL of the acid
solution required 27.5 mL of the NaOH solution to reach the end point, what is the
molarity of the H3PO4 solution?
a) 0.0183 M b) 0.0183 moles
c) 1.0183 M.
d) 1.0183 moles
44) A solution of 0.15 M in NH3 and 0.25 M in ammonium chloride, NH4Cl. What is the pH of
the solution? Ka for ammonium ion is 5.6 X 10–10.
a) 8.03
b) 9.03
c) 7.03
d) 11.03
45)Calculate the hydrogen concentration in a rainwater sample with a pH of 6.3.
a) 5.01 X 10+7 M
b) 5.01 X 10–7 M
c) 6.01 X 10–7 M
d) 6.01 X 10+7 M
46) Calculate the hydrogen concentration in an ammonia solution with a pH of 13.4
a) 3.98 X 10-4 M
b) 3.98 X 10-14 M
c) 3.98 X 10+14 M
d) 3.98 X 10+4 M
47) Calculate the hydrogen ion concentration a solution of NaOH with pOH = 1.5
a)3.16 X 10–13 M
b) 3.16 X 10–3 M c) 3.16 X 10+13 M
d) 3.16 X 10+3 M
48) What is the pH of a 0.100 M solution of the weak acid phenol, C6H5OH? Ka for phenol is 1.3 X 10–10.
a) 5.44
b) 3.44
c) 2.44
d)
6.44
49) Which one of the following is the weakest acid?
A) HF (Ka = 6.8 × 10-4)
B) HClO (Ka = 3.0 × 10-8)
C) HNO2 (Ka = 4.5 × 10-4)
D) HCN (Ka = 4.9 × 10-10)
E) Acetic acid (Ka = 1.8 × 10-5)
50) The solubility of slightly soluble salts containing basic anions is proportional to the pH of the solution.
A) FALSE
B) TRUE