Instructor: Nicole Stevens
1 of 9
WInter 2008
Chemistry 100 Exam 2
Part 1: Objective
You may write on this part of the test, but MARK YOUR FINAL ANSWERS on the bubble sheet provided.
1.
Which of the following does NOT generally characterize a base?
a. bitter taste
d. has a pH lower than 7
b. accepts a proton in water
e. yields an OH- in water
c. turns red litmus paper blue f. all of these characterize a base
2.
Which of the following chemicals would act as neither an acid or a base in water?
a. HCl
d. H2SO4
b. NaOH
c. NaCl
e. HNO3
f. all of these would act as an acid or base in water
Consider the pH scale at the end of Part 1 for questions 3-5.
3. Which is the most acidic?
a. milk
d. drinking water
b. bread
e. urine
c. blood
f. potato
4.
Soil is approximately how many times more acidic than seawater?
a. 3.0
d. 100
b. 30
e. 1000
c. 300
f. 10,000
5.
Which item from the pH scale has a hydrogen ion [H +] concentration of 6.3 x 10-5 M?
a. coffee
d. apple juice
b. urine
e. tomato
c. milk
f. none of the above
6.
What statement below is not true of acid rain?
a. acid rain can be very acidic, much lower pH than neutral
b. acid rain is a problem over many highly populated cities
c. adic rain has shown to be a problem that affects the environment
d. acid rain is due mostly to acids being dumped into rivers & the ocean by industrial plants
e. acid rain distribution is affected by wind patterns
f. all of the above are true
g. none of the above are true
7.
We tested several common acids and bases in lab. Which of the following is most likely basic?
a. toilet bowl cleaner
d. cream of tartar
b. vinegar
e. carbonated soda
c. soap
f. all of the above are acidic
8.
Which description below best represents an oxidation?
a. sodium atom becomes a sodium ion
b. any atom gains an electron to become an ion
c. chlorine atom becomes a chlorine ion
d. calcium ion becomes a calcium atom
e. all of these are oxidation reactions
9.
Which of the following represents the oxidation number of sulfur in sodium sulfite?
a. -2
d. +3
b. 0
e. +4
c. +2
f. +6
2 of 9
Instructor: Nicole Stevens
WInter 2008
Chemistry 100 Exam 2
Part 1: Objective
You may write on this part of the test, but MARK YOUR FINAL ANSWERS on the bubble sheet provided.
For each compound on the left (questions 10-16), select the correct oxidation number of nitrogen on the right.
Oxidation numbers may be used more than once!
10
nitrite ion
a. -3
b. -2
11. ammonium ion
c.
d.
e.
f.
g.
h.
i.
j.
12. nitrate ion
13. nitrogen dioxide
14. hyponitrite ion
-1
0
+1
+2
+3
+4
+5
+6
15. nitrogen trichloride
16. nitrogen monoxide
Refer to the list of characteristics below for questions 17-18.
A. Contains only single bonds
D. Contains a nitrogen
B. Contains one or more double bonds
E. Contains one or more oxygens
C. Contains one or more triple bonds
F. Soluble in water
17. Which characteristic(s) is/are true of the simplest amine?
a. A
e. C, D and E
b. B
f. A and E
c. C
g. A and D
d. A, D and F
h. B, D and E
18. Which characteristic(s) is/are true of the simplest amide?
a. A
e. A, D, and F
b. B
f. A, D and E
c. C
g. C, D and E
d. A and D
h. A, E and F
i.
j.
A, E and F
none of these
i.
j.
B, D, E and F
none of these
Refer to the molecules at the end of Part 1 and select the molecule(s) that fit each description (questions 19-21).
19. Molecules that are isomers of each other
a. A and C
e. F and H
i. B and E
b. B and F
f. G and H
j. none are isomers of each other
c. D and E
g. B, E and H
d. G and H
h. A, F and H
20. Unsaturated hydrocarbon(s)s
a. A, C and D
b. A and C
c. A, C, D and F
d. B and E
e.
f.
g.
h.
A, C and F
D and E
B and G
G and H
i.
j.
F, G and H
B, E, G and H
e.
f.
g.
h.
E
F
G
B and E
i.
j.
B and G
B, E, and G
21. Ester
a.
b.
c.
d.
A
B
C
D
3 of 9
Instructor: Nicole Stevens
WInter 2008
Chemistry 100 Exam 2
Part 1: Objective
You may write on this part of the test, but MARK YOUR FINAL ANSWERS on the bubble sheet provided.
22. Which of the following conditions is/are necessary for polymerization to occur?
a. heat
e. A and B
i. all of the above
b. water
f. B and C
j. none of the above
c. pressure
g. A, C and D
d. catalyst
h. A, B, and D
23. Which of the following molecule types is the basis of most synthetic polymers we discussed?
a. alkanes
d. alcohols
g. any of these
b. esters
e. amines
h. none of these
c. alkenes
f. amides
24. Which polymer below is NOT formed by condensation polymerization?
a. polyurethane
e. polyacrylate
b. polyamide
f. all of these are condensation polymers
c. polyester
g. none of these are condensation polymers
25. Which of the following are natural polymers?
a. nylon
b. DNA
c. rubber
d. polyester
e.
f.
g.
h.
A and B
B and C
C and D
A, B, and C
Mark questions 26-30 true or false.
i.
j.
B, C, and D
all of the above
a. TRUE
b. FALSE
26. Addition polymerization requires the removal of a water molecule between 2 carbon chains to be joined.
27. An acid or base is "strong" if it easily come apart (dissociates) in water.
28. Cut fruit turns brown because the iron in the fruit undergoes reduction to form an "organic rust."
29. The general formula for writing an alkyne is C n H2n .
30. In general, hydrocarbonscan be used as solvents, anesthetics, flavorings, perfumes and other products.
Instructor: Nicole Stevens
4 of 9
WInter 2008
Chemistry 100 Exam 2
Part 1: Objective
You may write on this part of the test, but MARK YOUR FINAL ANSWERS on the bubble sheet provided.
Instructor: Nicole Stevens
5 of 9
WInter 2008
Chemistry 100 Exam 2
Part 1: Objective
You may write on this part of the test, but MARK YOUR FINAL ANSWERS on the bubble sheet provided.
6 of 9
Instructor: Nicole Stevens
WInter 2008
Name
Chemistry 100 Exam 2
Part 2: Write-on
Write your answers directly on this part of the test. Please write as clearly as possible and show all work!
I.
Consider an acid-base neutralization reaction between sulfurous acid (H 2SO3) and aluminum hydroxide.
a. Write the balanced equation for this reaction.
3 pts.
3H2SO3 + 2Al(OH)3 → 6H2O + Al2(SO3)3
b. Name both products in this reaction.
water
1/2 pt. each
aluminum sulfite
c.
2 pt.
If sulfurous acid has a pH of 3.8, what is its hydrogen ion [H +] concentration? (2 decimal places)
(-1/2 pt. if wrong decimal places)
[H+] = 10-pH = 10-3.8 = 1.58 x 10-4 M
(-1/2 pt. if no units)
e. What is the oxidation number of sulfur in sulfurous acid?
+4
f.
+3
1/2 pt.
What is the oxidation number of aluminum in aluminum hydroxide?
1/2 pt.
II.
Draw a molecule that contains 3 carbons single-bonded to each other, and a carboxyl group. Hydrogens make
up the rest of the bonds.
Make sure each C only has 4 bonds!
-1/2 each for extra bonds
3 pts.
a. Name this molecule.
propanoic acid
1 pt.
b. Name 2 physical properties of this molecule.
soluble in water (polar), weak acid, sour taste
1 pt. each
donate an H+ in water, neutralize base
c.
2 pt.
If a solution of this molecule has a hydrogen ion concentration [H +] of 9.72 x 10-5 M, what is its pH?
(1 decimal place)
pH = -log(H+) = -log(9.72 x 10-5) = 4.0
III.
(-1/2 pt. if wrong decimal places)
Write the molecular formula, name and a physical property of each of the following molecules:
a. An alkyne containing 10 hydrogens.
Formula:
C6H10
Name:
Hexyne
Physical property:
insoluble, non-polar, flammable, liquid
Formula:
C10H22
Name:
Decane
Physical property:
insoluble, non-polar, liquid, flammable,
1 pt. each
b. An alkane containing 10 carbons.
7 of 9
Instructor: Nicole Stevens
WInter 2008
Name
Chemistry 100 Exam 2
Part 2: Write-on
Write your answers directly on this part of the test. Please write as clearly as possible and show all work!
IV.
Pentene reacts with oxygen during combustion to form carbon dioxide and water.
a. Write the balanced equation.
3 pts.
2C5H10 + 15O2 → 10CO2 + 10H2O
2 pts.
b. Assign oxidation numbers to all elements in the reaction.
Reactants
Products
C = -2
→ C = +4
H = +1
→ H = +1
May be written above the equation
O=0
→ O = -2
c.
2 pts.
Is this a redox reaction? If so, what's being oxidized, being reduced, oxidizing and reducing agents?
YES, this is a redox reaction.
Carbon changes from oxidation number -2 to +4, so it is being oxidized and acts as the
reducing agent
Oxygen changes from oxidation number 0 to -2, so it is being reduced and acts as the
oxidizing agent
d. List 2 physical properties of pentene.
Non-polar, unsaturated, liquid, flammable
2 pts.
Insoluble in water, toxic
V.
Let's discuss rubber!
a. Draw the monomer of rubber, using the bracket structure we discussed in class.
3 pts.
Make sure C's double bonded, joining bonds are
on the upper carbons, correct formulas, brackets and
the n subscript
b. What is the name of the rubber polymer?
polyisoprene
1 pts.
c.
4 pts.
Discuss a process in which rubber is strengthened. Please include things like what this process is
called, who discovered it and when, what the process involves, what the result is, etc.). Draw a
picture if you'd like!
Rubber is strengthened by a process called vulcanization. The process was discovered in 1844 by
Charles Goodyear. The process requires heat and sulfur, and as a result the rubber polymers
are cross-linked or joined by sulfur bridges (disulfide bonds). These sulfur bridges make the rubber
stronger, while still allowing flexibility.
+1 pt. each for any of the underlined information
and the picture, up to 4 pts.
1 pt.
d.
Name a common product, OTHER THAN TIRES, that is made from rubber.
racketballs, shoe soles, rubber cement, erasers
8 of 9
Instructor: Nicole Stevens
WInter 2008
Name
Chemistry 100 Exam 2
Part 2: Write-on
Write your answers directly on this part of the test. Please write as clearly as possible and show all work!
VI.
Using the bracket structure discussed in class, draw the monomer of each of the following polymers:
a. Polyvinyl chloride
Look for brackets, joining bonds,
3 pts.
correct groups on the C's and
the n subscript in the corner
b. Polyvinyl acetate
3 pts.
c.
Polyacrylate
3 pts.
d. Polypropylene
3 pts.
VII. Name one common product made from each of the following polymers:
a. Polyester
clothing, packaging containers, fibers
b. Polyvinylidene chloride
packaging, Saran wrap, seat covers
c.
non-stick coating (Teflon), gaskets, bearings
1 pt. each
Polytetrafluoroethylene
9 of 9
Instructor: Nicole Stevens
WInter 2008
Name
Chemistry 100 Exam 2
Part 2: Write-on
Write your answers directly on this part of the test. Please write as clearly as possible and show all work!
BONUS!!
5 pts.
a. Molecules with what 2 types of functional groups react together to form polyesters?
Carboxylic acids
1 pt. each
3 pts.
Alcohols
b. Draw an example of these two molecule types reacting and show/explain how they'd join to form the
polyester.
If no picture:
+1 if they say it's a condensation polymer, meaning a water molecule leaves
+1 if they say it's joined by ester linkages or draw the ester group