CH 223 SPRING 2011 - FINAL EXAM
June 6, 2011
This exam has 33 questions worth 5 pts each, plus one question worth 3 pts.
The total possible score is 168 pts.
DO NOT OPEN THIS EXAM UNTIL TOLD TO DO SO
Before the exam begins you can do the following on the Scantron answer sheet. Use a #2 pencil.
1.
Fill in your name (LAST NAME, FIRST NAME) in the large box on the left. Don't forget
to bubble in the circles below your name.
2.
Fill in your student ID number in the box labeled "IDENTIFICATION NUMBER". Do not
use dashes or blank spaces. Fill in the circles as well.
3.
In the box labeled "CLASS SECTION NUMBER", enter the appropriate number
8 am class = section 001 (Nafshun)
12pm class = section 003 (Watson)
4.
9 am class = section 002 (Nafshun)
3pm class = section 004 (Ferguson)
There is no "TEST FORM NUMBER"
ONLY ONE APPROVED NOTECARD IS ALLOWED
ALL PHONES AND OTHER ELECTRONIC DEVICES
OTHER THAN CALCULATORS MUST BE OFF
You may keep this exam packet and your notecard when the exam period is
complete.
Show your ID and hand in the Scantron answer sheet to a TA at the end of the
exam.
PTE
Ka[CH3COOH (aq)] = 1.80 x 10-5
(acetic acid)
Ka[CH2ClCOOH (aq)] = 1.40 x 10-3
(chloroacetic acid)
Ka[HCOOH (aq)] = 1.80 x 10-4
(formic acid)
Ksp [PbF2] = 3.6 x 10-8
Ksp [Cd(OH)2] = 7.2 x 10-15
Ka[HF (aq)] = 1.80 x 10-5
(acetic acid)
Ka[C6H5COOH (aq)] = 6.30 x 10-5
(benzoic acid)
Kb[NH3 (aq)] = 1.80 x 10-5
(ammonia)
Kb [CH3CH2NH2] = 5.37 x 10-4
(ethylamine)
Ksp [MgF2] = 3.7 x 10-8
Ksp [PbI2] = 1.4 x 10-8
Ka[niacin (aq)] = 1.5 x 10-5
Spectrochemical series: CN- > NO2- > en > NH3 > NCS- > |||division||| > H2O > OH- > F- > ClF = 96,485 C/mole eS = k ln W
R = 8.314 J/mol∙K
NA = 6.02 x 1023
h = 6.626 x 10-34 J∙s/photon ∆Gºrxn = -RT ln K
∆Grxn = ∆Gºrxn + RT ln Q
c = 3.00 x 108 m/s
Ecell = E°cell -
∆Gº = -nF E°cell
ln Q
∆G = ∆H - T∆S
∆E =
1 Amp =
ΔG°f (kJ/mol)
HNO3(g)
-73.5
N2H4(l)
149.3
H2O(l)
-237.1
Reduction Half-Reaction
Acidic Solution
F2 (g) + 2 e- → 2F- (aq)
O3(g) + 2 H+(aq) + 2 e- → O2 (g) + H2O(l)
S2O82- (aq) + 2 e- → 2 SO42- (aq)
H2O2 (aq) + 2H+ (aq) + 2 e- → 2 H2O(l)
MnO4-(aq) + 8H+ (aq) + 5 e- → Mn2+(aq) + 4 H2O(l)
PbO2 (s)+ 4H+ (aq) + 2 e- → Pb2+(aq) + 2 H2O(l)
Cl2 (g) + 2 e- → 2 Cl- (aq)
Cr2O72- (aq) + 14 H+ (aq) + 6 e- → 2 Cr3+(aq) + 7 H2O(l)
MnO2(s) + 4H+ (aq) + 2 e- → Mn2+(aq) + 2 H2O(l)
O2(g) + 4H+ (aq) + 4 e- → 2 H2O(l)
2 IO3- (aq) +12H+ (aq) + 10 e- → I2(s) + 6 H2O(l)
Br2(l) + 2 e- → 2 Br- (aq)
NO3- (aq) + 4H+ (aq) + 3 e- → NO(g) + 2 H2O(l)
Ag+ (aq) + e- → Ag(s)
Fe3+(aq) + e- → Fe2+(aq)
O2(g) + 2H+ (aq) + 2 e- → H2O2(aq)
I2(s) + 2 e- → 2 I- (aq)
I3-(aq) + 2 e- → 3 I- (aq)
Cu2+(aq) + 2 e- → Cu(s)
SO42- (aq) + 4H+ (aq) + 2 e- → 2 H2O(l) + SO2(g)
Sn4+ (aq) + 2 e- → Sn2+ (aq)
S(s) + 2H+ (aq) + 2 e- → H2S(g)
2H+(aq) + 2 e- → H2(g)
Pb 2+(aq) + 2 e- → Pb(s)
Sn2+(aq) + 2 e- → Sn(s)
Co2+(aq) + 2 e- → Co(s)
Cr3+(aq) + e- → Cr2+(aq)
Fe2+(aq) + 2 e- → Fe(s)
Zn2+(aq) + 2 e- → Zn(s)
Al3+(aq) + 3 e- → Al(s)
Mg2+(aq) + 2 e- → Mg(s)
Na+(aq) + e- → Na (s)
Ca2+(aq) + 2 e- → Ca(s)
K+(aq) + e- → K(s)
Li+(aq) + e- → Li(s)
Basic Solution
O3(g) + H2O(l) + 2 e- → O2(g) + 2 OH-(aq)
OCl-(g) + H2O(l) + 2 e- →Cl-(aq) + 2 OH-(aq)
O2(g) + 2 H2O(l) + 4 e- →4 OH-(aq)
2 H2O(l) + 2 e- → H2(g) + 2 OH-(aq)
E º, volt
+2.866
+2.075
+2.01
+1.763
+1.51
+1.455
+1.358
+1.33
+1.23
+1.229
+1.20
+1.065
+0.956
+0.800
+0.771
+0.695
+0.535
+0.530
+0.340
+0.17
+0.154
+0.14
0
-0.125
-0.137
-0.277
-0.410
-0.440
-0.763
-1.676
-2.356
-2.713
-2.84
-2.924
-3.040
+1.246
+0.890
+0.401
-0.828
1.
Niacin, one of the B vitamins, has the following molecular structure:
O
O-H
N
What is the [H3O+] of a 0.020M aqueous solution?
2.
(A)
5.5 x 10-4 M
(B)
3.0 x 10-7 M
(C)
0.020 M
(D)
4.0 x 10-4 M
(E)
2.8 x 10-4 M
Which statement about the pH curve is TRUE.
The titration used 0.100 M NaOH and 15.00 mL of an acid.
A) The acid could be 0.100 M HCl.
B) The acid could be 0.100 M HCN.
C) The acid could be 0.100 M H3PO4.
D) The acid could be 0.200 M HCN.
E) The acid could be 0.200 M HCl.
3.
4.
5.
What would the pH of an aqueous solution made from calcium acetate, Ca(CH3COO)2 be?
(A)
Neutral, pH=7
(B)
Acidic, pH<7
(C)
Basic, pH>7
(D)
Need more information to determine
The pH of a buffer system which is 0.700 M CH3COOH (aq) and 1.40 M CH3COONa (aq) is:
(A)
0.700
(B)
2.00
(C)
2.85
(D)
4.44
(E)
5.05
A student titrates 0.452 grams of KHP (potassium hydrogen phthalate; MW=204.2 g/mol) to the
equivalence point with 34.08 mL of NaOH (aq). The concentration of the NaOH solution is:
(A)
15.4 M
(B)
13.6 M
(C)
0.0913 M
(D)
0.0650 M
(E)
0.0136 M
6.
7.
8.
Consider the reaction of ammonia (NH3), and water. The conjugate acid is:
(A)
H2O
(B)
NH3
(C)
HCOO-
(D)
H+
(E)
NH4+
The concentration of NaOH in water is gradually increased without changing the volume
significantly. Which of the following describes what happens to the concentrations of H3O+ and
OH-, the pH and the pOH?
Concentration of H3O+
Concentration of OH-
pH
pOH
(A)
increases
increases
increases
decreases
(B)
increases
decreases
increases
decreases
(C)
decreases
increases
decreases
increases
(D)
decreases
decreases
decreases
increases
(E)
decreases
increases
increases
decreases
The molar solubility of Ag2SO4 in water is 1.2×10-5 M. What is the value of Ksp?
(A)
3.5×10-5
(B)
6.9×10-15
(C)
5.6×10-10
(D)
1.4×10-10
(E)
1.7×10-15
9.
Which isomer is shown below?
H2N
Cl
Pt
2-
H2N
(A)
(B)
(C)
(D)
(E)
10.
Cis
Trans
Fac
Mer
Not an isomer
Which of the following Ti3+ complexes exhibits the shortest wavelength absorption in the visible
spectrum? [Ti(H2O)6]3+ [Ti(en)3]3+ [TiCl6]3(A)
(B)
(C)
(D)
(E)
11.
Cl
[Ti(H2O)6]3+
[Ti(en)3]3+
[TiCl6]3Cannot Determine
All have the same wavelength absorption
3+
How many unpaired electrons would you expect for the complex ion: [Mn(NH3)6] ?
(A)
(B)
(C)
(D)
(E)
1
2
3
4
5
12.
The Haber process for the production of ammonia is exothermic and involves the following
equilibrium reaction: N2 (g) + 3H2 (g) ↔ 2NH3(g). Assuming ΔHᵒ and ΔSᵒ do not change with
temperature predict the direction in which ΔGᵒ for this reaction changes with increasing temperatures.
A.
B.
C.
D.
Moves towards the reactants
Moves towards the products
The reaction is not temperature dependent and ΔGᵒ will not change
Values for ΔHᵒ and ΔSᵒ are needed to calculate ΔGᵒ
13.
14.
Which of the following statements involving the 3rd law of thermodynamics is FALSE?
(A)
It allows us to assign entropy values for substances at different temperatures
(B)
Perfect crystalline solids have zero entropy at 0K.
(C)
The standard molar entropy of elements is zero
(D)
The standard molar entropy of a gas is greater than a solid
(E)
The standard molar entropy increases with the number of atoms in a formula.
Which of the following processes have a ΔS > 0?
(A)
(B)
(C)
(D)
(E)
15.
CH3OH(l) → CH3OH(s)
N2 (g) + 3 H2 (g) → 2 NH3 (g)
CH4(g) + H2O (g) → CO(g) + 3 H2(g)
Na2CO3(s) + H2O(g) + CO2(g) → 2 NaHCO3(s)
All of the above processes have a ΔS > 0.
Calculate the ΔG°rxn for the following reaction (thermodynamic data at front of exam).
4 HNO3(g) + 5 N2H4(l) → 7 N2(g) + 12 H2O(l)
(A)
(B)
(C)
(D)
(E)
16.
6
- 3.298×10 J
- 3.298 kJ
3
- 3.886×10 kJ
3
- 2.393×10 kJ
3
+ 3.298×10 kJ
When the following redox reaction is balanced correctly in acidic solution you will
have ____H+ and ____H2O.
Mn2+ (aq) + BiO3- (s)  Bi3+ (aq) + MnO4- (aq)
(A)
(B)
(C)
(D)
(E)
14 H+ and 7 H2O
7 H+ and 7 H2O
7 H+ and 14 H2O
8 H+ and 4 H2O
2 H+ and 1 H2O
17.
An electrochemical cell consists of one beaker containing 1.0 M AgNO3(aq) into which dips a
piece of metallic silver and a second beaker containing 1.0 M Zn(NO3)2(aq) into which dips a
piece of metallic zinc. The beakers are connected by a salt bridge containing 1.0 M KNO 3(aq).
Which of the following statements will be TRUE when a wire is connected between the two
pieces of metal?
(A)
(B)
(C)
(D)
(E)
18.
19.
Electrons will flow from the silver to the zinc.
The cell voltage will be +0.04 V.
There will be no cell voltage as the overall reaction is non-spontaneous.
The silver will plate out on the zinc.
The value of n used to find ΔG° for this cell has the value 2.
A student provides a current of 8.0 amps through a solution of Co2+ (aq) for 6.00 hours. The
voltage is such that cobalt metal is deposited at the cathode. The mass of cobalt deposited is:
(A)
12.2 g
(B)
24.4 g
(C)
62.1 g
(D)
52.8 g
(E)
105 g
What is the name of the following structure?
(A)
(B)
(C)
(D)
(E)
2,4-diethylheptane
4,6-diethylheptane
2,4-dimethylheptane
4,6-dimethylheptane
5-ethyl-3-methyloctane
20.
The molecular formula of Vitamin C (shown below) is:
(A)
(B)
(C)
(D)
(E)
21.
is C7H8O6
is C7H6O6
is C7H4O6
is C6H4O6
is C6H8O6
Which of the following is NOT an isomer of 2-methyl-3-ethylheptane?
(A)
(B)
(C)
(D)
(E)
5-methylnonane
2-methyl-4-ethylheptane
2,2,3,4,4-pentamethylpentane
2,4-diethyl-3-isopropylpentane
decane
22.
Complete the following reaction:
23.
Complete the following condensation reaction:
24.
In a single step, CH2O is oxidized to:
(A)
(B)
(C)
(D)
(E)
25.
CH3CH3
CH3OH
benzene
an amide
HCOOH
Complete the following addition reaction:
26.
Which of the following functional groups is not present in Amoxicillin?
Amoxicillin
(A)
(B)
(C)
(D)
27.
amine
aldehyde
carboxylic acid
alcohol
A β-sheet is an example of
(A)
(B)
(C)
(D)
(E)
primary structure
secondary structure
tertiary structure
quaternary structure
an aldohexose
28.
The following is the structure of galactose. Which of the following statements is false:
(A)
(B)
(C)
(D)
(E)
29.
Galactose is a monosaccharide
Galactose is an aldohexose
Galactose has 5 chiral carbons
Galactose is a carbohydrate
Galactose is an aldehyde
Consider the fat molecule below. Which of the following is false?
O
H
O
H
O
C
O
H
C
O
H
C
H
(A)
(B)
(C)
(D)
(E)
O
It is a triglyceride
it is saturated
it contains cis bonds
it contains trans bonds
could undergo hydrogenation
30.
What monomer was reacted to create the following addition polymer?
31.
The organic product of benzene and
in the presence of AlCl3 is:
32.
Carnosine is highly concentrated in muscle and brain tissues. Carnosine is the dipeptide:
(A)
(B)
(C)
(D)
(E)
33.
Pro-Glu
Ala-Gly
Gly-Ala
Gln-His
His-Gln
DNA forms a double helix structure. Which of the following statements explains how this helix
forms?
(A)
The sugar groups form hydrogen bonds between two complementary strands to form a
helix.
(B)
The phosphate groups from two strands wrap around one another to form a helix.
(C)
The base groups form hydrogen bonds between two complementary strands to form a
helix.
(D)
The sugar and phosphate form a phosphoester linkage that bonds two complementary
strands to form a helix.
(E)
The sugar groups form hydrogen bonds between two complementary strands to form a
helix.
34.
Well, well, well... CH 223 is over. Time to...
(A)
head home, work a summer job, and try to forget about chiral carbons.
(B)
cry; possibly for hours.
(C)
two words: Twitter and Skittles.
(D)
refurnish my room to resemble Gilbert 124. I plan on reliving general chemistry every
day of my life; for it has been a breathtaking experience I cannot live without.
(E)
recover from the full-body discomfort brought on by the study of entropy.
[Any response will receive full credit; even no response.]
Questions 1 through 33 have five points attached (165 total). Any response to Question 34 will receive full
credit (3 Points total); even no response. The point total for this exam is 168 points. See the grade sheet for
grade computation details. Final exam keys, scores, and course grades will be posted on the CH 223 website
as they become available. Have a great life. Go out there and do some really cool stuff :)