CHEMISTRY 101
Hour Exam I
September 23, 2008
Adams/Denofrio
Name ______________________________
Signature ___________________________
Section _____________________________
This exam contains 17 questions on 7 numbered pages. Check now to make sure you have a complete exam. You have one hour and fifteen minutes to complete the exam.
Determine the best answer to the first 15 questions and enter these on the special answer sheet. Also, circle your responses in this exam booklet. Show all of your work and provide complete answers to questions 16 and 17.
1-15 (30 pts.) _________
16 (12 pts.) _________
17 (18 pts.) _________
Total (60 pts) _________
Useful Information:
Always assume ideal behavior for gases (unless explicitly told otherwise).
PV = nRT
R = 0.08206 L•atm/mol•K
K =

C + 273
Avogadro’s number = 6.022 x 10 23
STP = standard temperature and pressure = 0

C and 1.00 atm

CHEMISTRY 101
Hour Exam I
1. How many centimeters long is this arrow? (1 inch = 2.54 centimeters)
Fall 2008
Page No. 1
1 2 3 4 5 6 7 inches a) 11.68 cm b) 11.9 cm c) 12.446 cm d) 12 cm
2. How many of the following statements are true ? e) 6.008 cm
I. An observation is something that is witnessed and can be recorded.
II. A theory is an interpretation – a possible explanation of why nature behaves in a particular way.
III. Even though scientific models are simplifications of reality, they are based on observations and experiments so they eventually become natural laws.
IV. The kinetic molecular theory of gases helps explain why the volume of a gas increases when temperature is increased at constant pressure and moles.
V. If a theory is disproven, then all of the observations that support that theory are also disproven. a) 1 b) 2 c) 3
3. Which of the following is a homogeneous mixture? d) 4 a) potting soil b) sodium chloride c) pure water d) oil and vinegar dressing e) carbonated beverage (like Pepsi or Coke) e) 5
4. Which of the following best describes the substance XeF
4
?
I. Element
II. Molecule
III. Compound
IV. Heterogeneous mixture
V. Homogeneous mixture a) I, II b) III only c) II, III, IV d) II, III, V e) II, III

CHEMISTRY 101
Hour Exam I
Fall 2008
Page No. 2
5. Which of the following is the best microscopic representation of a molecule of BF
3
? a) b) c) d) e)
6. How many fluorine atoms are in 7.86 grams of BF
3
? a) 2.09 × 10 23 F atoms b) 6.02 × 10
23
F atoms c) 6.98 × 10
22
F atoms d) 3.46 × 10
22
F atoms e) 2.33 × 10
22
F atoms
7. What mass of hydrogen gas is needed to fill a 40.9-L container to a pressure of 1.09 atm at 27°C? a) 1.82 g b) 3.65 g c) 10.14 g d) 20.28 g e) 40.56 g
8. An 11.7-L sample of gas is determined to contain 0.60 mol of nitrogen gas. At the same temperature and pressure, how many moles of gas would there be in a 25.0-L sample? a) 0.28 mol b) 0.78 mol c) 1.3 mol d) 2.6 mol e) 22 mol

CHEMISTRY 101
Hour Exam I
Fall 2008
Page No. 3
9. During lecture one day, we made a “cannon” by pouring liquid nitrogen into a large test tube and putting a cork into the top of the test tube. After some time, the cork
“popped” out of the test tube. What caused this to happen? a) As the liquid nitrogen boiled to a gas, the test tube warmed up, so it contracted, forcing the cork to shoot off the top. b) The nitrogen turned from a gas to a liquid, creating a vacuum inside the test tube so that atmospheric pressure could pop the cork off the top. c) The friction of shaking the liquid in the tube caused the cork to get looser until it just popped off. d) The liquid nitrogen turned into a gas, and the gas molecules hit the insides of the container and the bottom of the cork, causing a greater pressure inside the tube versus outside the tube. e) Because the moles of gas stayed constant inside the test tube, the increase in temperature caused an increase in pressure inside the tube, which popped the cork off the top.
10. Examine the following table of formulas and names. Which of the compounds are named correctly ?
Formula Name
I
II
P
2
O
5
ClO
2
PbI
4
CuSO
4
Diphosphorus pentoxide
Chlorine oxide
Lead iodide a) I, II
III
IV Copper(I) sulfate b) I, III, IV c) I, IV d) I only e) IV only
11. A compound has a formula of C x
O y
. The compound is 33.4% carbon by mass and has a molar mass of about 144 g/mol. What is the molecular formula for this compound? e) C
4
O
6 a) CO
2 b) C
8
O
12 c) C
8
O
16 d) C
2
O
12. Which of the following most accurately describes a mole?
3 a) The number of molecules present in 44.01 grams of carbon dioxide. b) The number of atoms present in 12.01 atomic mass units of carbon. c) 6.022 × 10
23
grams present in 16.00 atoms of oxygen. d) The equivalent of 1 amu = 1.66 × 10
–24
grams. e) The number of atoms present in any sample of a compound because it is always equal to 6.022 × 10 23
.

CHEMISTRY 101
Hour Exam I
Fall 2008
Page No. 4
13. What is the molar mass of nickel(II) carbonate? a) 74.02 g/mol b) 118.7 g/mol c) 134.7 g/mol d) 178.71 g/mol e) 296.09 g/mol
14. Recall Station I from your lab in which a plastic bottle was filled with water and a
“diver” made of a test tube. Which of the following is the best explanation as to why the “diver” sinks when the bottle is squeezed on the sides from the outside? a) The air inside the test tube is compressed allowing more water to flow into the tube, increasing the mass of the “diver” and thus increasing its density. b) More moles of gas are forced into the test tube, therefore increasing the pressure inside the “diver” and forcing it to sink. c) The volume of the air inside the test tube decreases, therefore increasing the pressure on the “diver” and forcing it to sink. d) The volume of gas inside the test tube decreases while the mass of the “diver” stays constant, thus increasing its density. e) Squeezing the bottle causes gravity to increase on the “diver” so that it sinks.
15. 88.02 g of carbon dioxide and 92.02 g of dinitrogen tetroxide are mixed in a rigid steel container. Which of the following is true regarding the partial pressures of the two gases? a) The partial pressure of carbon dioxide is half that of dinitrogen tetroxide. b) The partial pressure of the gases is the same. c) The partial pressure of carbon dioxide is twice that of dinitrogen tetroxide. d) The partial pressure of carbon dioxide is four times that of dinitrogen tetroxide. e) Without knowing either the temperature or the volume of the gases, it is impossible to draw any conclusions about the partial pressures of the two gases.

CHEMISTRY 101
Hour Exam I
Fall 2008
Page No. 5
16. Answer the questions below. Only complete and coherent explanations will receive full credit. Please limit your answers to the space provided.
A metal ion with a +2 charge forms a compound with a member of the halogen group. The metal ion contains 34 neutrons and 27 electrons. a) Identify the metal ion and determine its mass number. Justify your answer. b) Write the general formula for your compound representing X as your halogen ion.
Explain how you determined your formula. c) The compound is 71.55% X by mass. What is the identity of the halogen in this compound? Write the correct name for this compound. Show all work.

CHEMISTRY 101
Hour Exam I
17. Consider the following gas container equipped with a movable piston.
Fall 2008
Page No. 6 a) If you increased the number of moles of gas in the container by a factor of two, by what factors would the pressure and the volume change (assuming constant temperature)? Be sure to support your answer using the kinetic molecular theory.
(Hint: Think about how a moveable piston works. It is a lot like a balloon.) b) By what factor (twice as much, half as much, etc.) would the pressure of the gas change if the volume changed from A to B and the piston was locked in place
(also assume constant temperature and moles)? Be sure to support your answer using the kinetic molecular theory.

CHEMISTRY 101
Hour Exam I
Fall 2008
Page No. 7 c) After the piston is locked in place, the temperature of the gas is doubled from
30.°C to 60.°C. Will the pressure increase by a factor of two? Be sure to support your answer using the kinetic molecular theory. d) If the container contains 4.00 g of oxygen gas at 45°C at 1.03 atm, what volume does it occupy?