Download CHEMISTRY 101 Name Mock Final Exam Spring 2014 Signature Dr

CHEMISTRY 101
Mock Final Exam
Spring 2014
Dr. D. DeCoste
Name ______________________________
Signature ___________________________
T.A. _______________________________
This exam contains 50 questions on 9 numbered pages. Check now to make sure you
have a complete exam. You have three hours to complete the exam. Determine the best
answer to the 50 questions and enter these on the special answer sheet.
1-50
(50 pts.)
_________
Useful Information:
Always assume ideal behavior for gases (unless explicitly told otherwise).
PV = nRT
R = 0.08206 Latm/molK
K = °C + 273
Avogadro’s number = 6.022 x 1023
STP = standard temperature and pressure = 0°C and 1.00 atm
Solubility Rules:
1. Most nitrate salts are soluble.
2. Most salts of sodium, potassium, and ammonium cations are soluble.
3. Most chloride salts are soluble. Exceptions: silver(I), lead(II), and mercury(I)
chloride.
4. Most sulfate salts are soluble. Exceptions: calcium, barium, and lead (II) sulfate.
5. Most hydroxide salts can be considered insoluble. Soluble ones: sodium, potassium,
and calcium hydroxide.
6. Consider sulfide, carbonate, and phosphate salts to be insoluble. Soluble ones:
sodium and potassium.
CHEMISTRY 101
Mock Final Exam
Spring 2014
Page No. 1
1. In lab one day, you measure 4.21 g of a substance. Your lab partner measures 97.46 g
of the same substance. You put your samples together in one beaker and record the
mass. How many significant figures should you report?
a) 1
b) 2
c) 3
d) 4
e) 5
2. Which of the following has the greatest molar mass?
a)
b)
c)
d)
e)
cobalt(II) oxide
cobalt(II) fluoride
cobalt(II) sulfate
cobalt(III) fluoride
cobalt(II) chloride
3. How many of the following statements are true?
I.
All molecules are compounds.
II. The terms “atom” and “element” always have the same meaning.
III. Ions are formed by adding or removing protons or electrons.
IV. Empirical formulas and molecular formulas are always different.
a) 4
b) 3
c) 2
d) 1
e) 0
4. Which of the following solutions has the greatest number of nitrate ions in solution?
a)
b)
c)
d)
e)
5.0 mol potassium nitrate dissolved in water
4.0 mol magnesium nitrate dissolved in water
6.0 mol sodium nitrate dissolved in water
2.0 mol iron(III) nitrate dissolved in water
At least two of the above (a-d) have an equally great number of nitrate ions in
solution.
5. Which of the following atoms has two more electrons than protons as a stable ion in a
compound?
a) S
b) Ar
c) Na
d) Ca
e) Cl
6. A single molecule of a particular compound has a mass of 4.65 x 10-23 g. Which of
the following could be this compound?
a)
b)
c)
d)
e)
carbon monoxide
water
nitrogen dioxide
ammonia (NH3)
sulfur trioxide
CHEMISTRY 101
Mock Final Exam
Spring 2014
Page No. 2
7. Given equal masses of each of the following, which contains the greatest mass of
phosphorus?
a)
b)
c)
d)
e)
sodium phosphate
magnesium phosphide
phosphorus pentachloride
phosphorus tribromide
barium phosphate
8. The percent by mass of nitrogen is 46.7% for a species containing only nitrogen and
oxygen. Which of the following could be this species?
a)
b)
c)
d)
e)
the nitrate ion
nitrogen dioxide
nitrogen monoxide
dinitrogen oxide
None of the above are 46.7% nitrogen by mass.
9. A compound mislabeled “phosphorus oxide” is known to be 43.6% phosphorus by
mass. You also know that the molecular formula has a molar mass twice that of the
empirical formula. What is the molecular formula for this compound?
a) PO3
10.
d) P4O10
e) None of these
b) 17.5%
c) 29.6%
d) 35.0%
e) None of these
You have a sample of gas at 25°C. At what temperature does the sample have
twice the average kinetic energy?
a) 50°C
12.
c) PO4
What is the percent by mass nitrogen in ammonium nitrate?
a) 9.86%
11.
b) P2O6
b) 298°C
c) 323°C
d) 596°C
e) none of these
Consider 2 steel containers with the same volume, at the same temperature. You
add helium gas (He) to one container and the same mass of argon gas (Ar) to the
other. How do the pressures inside the containers compare?
a) The pressures are the same.
b) The pressure inside the tank filled with helium is ten times greater than the
pressure inside the tank filled with argon.
c) The pressure inside the tank filled with argon is ten times greater than the
pressure inside the tank filled with helium.
d) The pressures inside the tanks are different but we need to know the masses of
each gas to answer this question.
e) None of the above.
CHEMISTRY 101
Mock Final Exam
13.
Consider 2 steel containers with the same volume, at the same temperature. You
have 25.0 g of argon gas (Ar) in one of the tanks, and note the pressure to be 1.00 atm.
You add 20.0 g of a different gas to the other tank, and note the pressure to be 2.00 atm.
Which of the following could be the other gas?
a) CH4
14.
b) N2
c) He
d) Cl2
e) CO2
A 20.0-g sample of a gaseous hydrocarbon (a compound consisting of only carbon
and hydrogen) is placed in a balloon at 1.00 atm and 25°C. The volume of the
balloon is 16.3 L. The 20.0-g sample of this compound contains 16.0 g carbon.
Determine the molecular formula for this compound.
a) CH3
15.
Spring 2014
Page No. 3
b) CH4
c) C3H8
d) C3H9
e) C2H6
Under which of the following conditions does a real gas act most ideally?
a)
b)
c)
d)
e)
P = 1.00 atm, T = 400.0°C
P = 2.00 atm, T = 400.0°C
P = 1.00 atm, T = 200.0°C
P = 1.00 atm, T = 25K
STP
16. The molar mass of iron(II) oxide (units of g/mol) is
a) 71.85
b) 87.85
c) 127.7
d) 159.7
e) none of these
17. Consider equal mass samples of carbon dioxide, water, and sodium oxide. Rank
these from most to least number of oxygen atoms in each sample.
a) carbon dioxide, water, sodium oxide
b) water, sodium oxide, carbon dioxide
c) carbon dioxide, sodium oxide, water
d) sodium oxide, water, carbon dioxide
e) water, carbon dioxide, sodium oxide
18. Consider the chemical equation H2(g) + O2(g) → H2O(l). Can we balance this
equation so that the coefficient for H2(g) is “1”?
a) No. We never have a coefficient of “1” in the standard form of a balanced
equation.
b) Yes. With a “1” for the coefficient of H2(g), the equation is balanced in standard
form.
c) No. This would require one of the other coefficients to be a fraction, and this is
never allowed.
d) Yes. By having a coefficient of “1” for H2(g), the equation can still be balanced,
although not in standard form.
e) No. There is no way to balance this equation with H2(g) having a coefficient of
“1”.
CHEMISTRY 101
Mock Final Exam
Spring 2014
Page No. 4
Questions 19 and 20 deal with an aqueous solution of calcium nitrate added to an
aqueous solution of sodium phosphate. Write and balance the equation for this reaction
to answer questions 2 and 3.
19. What is the sum of the coefficients when the molecular equation is balanced in
standard form?
a) 4
20.
b) 5
c) 7
d) 11
e) 12
What is the formula of the solid formed in the reaction?
a) Ca(PO4)2
b) CaPO4
c) Ca3(PO4)2
d) Ca3(PO3)2
e) None of
these
----------------------------------------------------------------------------------------------------------21.
Sulfuric acid (which is an aqueous solution of hydrogen sulfate) reacts with the base
sodium hydroxide. What is the coefficient of water in the equation when it is
balanced in standard form?
a) 1
22.
d) 4
e) Water is not in the equation.
Mix 100.0 mL of 0.800 M NaOH with 600.0 mL of 0.100 M NaOH.
Take 10.0 mL of 2.00 M NaOH and add 100.0 mL water.
Take 8.00 g of NaOH and dissolve it in 250.0 mL solution.
Mixing the solution made in part a above with the solution made in part c.
None of the above.
You have 245 mL of a sugar solution at 1.20 M. The next day the sugar solution
has a concentration of 1.30 M. How much water evaporated from the solution?
a)
b)
c)
d)
e)
24.
c) 3
Which of the following makes a 0.200 M NaOH solution?
a)
b)
c)
d)
e)
23.
b) 2
18.8 mL
26.4 mL
226 mL
265 mL
This is an impossible problem. The concentration of the solution will never go up.
Which of the following aqueous solutions has the greatest number of chloride ions
in solution?
a) 2.0 L of a 5.0 M sodium chloride solution
b) 1.0 L of a 3.0 M potassium chloride solution
c) 1.0 L of a 4.0 M aluminum chloride solution
d) 1.0 L of a 4.0 M iron(II) chloride solution
e) 2.0 L of a 4.0 M calcium chloride solution
CHEMISTRY 101
Mock Final Exam
25.
Hydrochloric acid is made by dissolving HCl in water. HCl is a gas that is very
soluble in water. You have 2.50 L of HCl gas at 1.00 atm and 25°C. You dissolve
this HCl in 225.0 mL of solution. What is concentration of hydrochloric acid?
a) 5.42 M
26.
Spring 2014
Page No. 5
b) 1.22 M
c) 0.454 M
d) 0.102 M
e) None of these
Consider the reaction represented by the following unbalanced chemical equation
MnO2(s) + Al(s) → Mn(s) + Al2O3(s)
How many moles of Al2O3 can be produced from 1.25 mol MnO2 and an excess of
Al?
a) 0.833 mol
these
b) 1.00 mol
c) 2.00 mol
d) 2.50 mol
e) None of
27. Consider the reaction represented by the following unbalanced chemical equation
NH3(g) + Cl2(g) → NH4Cl(s) + NCl3(g)
What mass of NH4Cl can be produced from 10.0 g of NH3 and an excess of Cl2?
a) 160.5 g
b) 53.5 g
c) 35.3 g
d) 23.6 g
e) None of
these
----------------------------------------------------------------------------------------------------------Questions 28 and 29 deal with adding a metal to HCl(aq). For metals that form a 2+
charge in an ionic compound, the general equation is
M(s) + 2HCl (aq) → MCl2(aq) + H2(g)
10.0 g of a metal is added to 500.0 mL of 1.00 M HCl and the hydrogen gas is collected at
25°C and 1.00 atm.
28. Which of the following metals will give rise to the smallest balloon?
a) Ca
b) Zn
c) Mg
d) The balloons will be the same size because HCl(aq) is the limiting reactant.
e) The balloons will be the same size although HCl(aq) is not the limiting reactant.
29. What is the volume of the balloon made by using the metal that gives rise to the
smallest balloon?
a) 1.47 L
b) 3.74 L
c) 5.21 L
d) 6.11 L
e) 10.1 L
-----------------------------------------------------------------------------------------------------------
CHEMISTRY 101
Mock Final Exam
30.
2.00 L of a 4.00 M solution of lead(II) nitrate is added to 3.00 L of a 5.00 M
solution of sodium iodide and a solid is formed. Which of the following correctly
labels the ion with the highest concentration after the reaction is complete, and the
ion that is not in solution after the reaction (concentration is 0 M)?
a)
b)
c)
d)
e)
31.
Spring 2014
Page No. 6
ion with highest concentration
Na+
NO3Pb2+
Na+
NO3-
0M
IPb2+
NO3Pb2+
I-
Consider the reaction as represented by the following unbalanced chemical
equation
N2 + H2 → NH3
In which of the following cases is nitrogen the limiting reactant?
a)
b)
c)
d)
e)
32.
Reacting 60.0 g of N2 with 10.0 g of H2.
Reacting 2.0 moles of N2 with 5.0 moles of H2.
Reacting 250.0 g of N2 with 60.0 g of H2.
Reacting 3.0 moles of N2 with 3.0 moles of H2.
Nitrogen is not limiting in any of the cases above.
Consider 2 reactants, A and B. The molar mass of A is greater than the molar mass
of B. You add equal masses of A and B together and let them react. Which of the
following statements must be true?
a) Reactant A must be limiting.
b) Reactant B must be limiting.
c) If the coefficient for B is greater than the coefficient of A in the balanced
equation, then reactant B must be limiting.
d) If the coefficient for A is greater than the coefficient of B in the balanced
equation, then reactant A must be limiting.
e) None of the above choices (a-d) must be true.
33.
You make two separate solutions by dissolving different solutes in equal volumes of
solution. One solute is lithium oxide. You have four times the mass of the other solute
in the other solution. The concentrations of both solutions (in molarity) are equal.
Which of the following is most likely the other solute?
a)
b)
c)
d)
e)
sodium chloride
iron(III) chloride
potassium nitrate
potassium bromide
sodium fluoride
CHEMISTRY 101
Mock Final Exam
Spring 2014
Page No. 7
34. You have 2 solutions of sodium chloride. One is a 2.00 M solution, the other is a 4.00
M solution. You have much more of the 4.00 M solution and you add the solutions
together. Which of the following could be the concentration of the final solution?
a) 2.60 M
b) 3.00 M
c) 3.80 M
d) 6.00 M
e) 7.20 M
35. Which of the following statements is false?
a)
b)
c)
d)
e)
Ionization energies are generally endothermic.
“Lower in energy” also means “more stable”.
The ground state is the lowest energy state.
In an exothermic chemical reaction, the products are more stable than the reactants.
All of the above statements (a-d) are true.
36. By considering electrons to have wave properties, we can better explain
a)
b)
c)
d)
e)
the existence of ionic bonds.
the idea of orbitals as probability distributions.
why water is a bent molecule.
the need for resonance structures when drawing some Lewis structures.
the relationship between boiling points and intermolecular forces.
37. Which of the following is the expected ground state electron configuration for antimony
(Sb)?
a)
b)
c)
d)
e)
[Kr] 5s24d104p2
[Kr] 5s25d105p3
[Kr] 5s24d105p3
[Xe] 5s24d105p3
none of these
38. Which of the following does not correctly match the species with the expected electron
configuration?
a)
b)
c)
d)
e)
A ground state calcium atom
[Ar] 4s2
The most stable ion for bromine
[Ar] 4s23d104p6
An excited state of sulfur
[Ne] 3s23p34s1
At least two of the above (a-c) are incorrectly matched.
All of the above (a-c) are correctly matched.
39. Which of the following species has the largest ionization energy?
a) Rb
b) Na
c) O
d) S
e) Be
CHEMISTRY 101
Mock Final Exam
Spring 2014
Page No. 8
40. Which of the following is true concerning trends on the periodic table?
a) In general, smaller atoms have larger ionization energies, and smaller
electronegativity values.
b) In general, smaller atoms have smaller ionization energies, and smaller
electronegativity values.
c) In general, smaller atoms have smaller ionization energies, and larger
electronegativity values.
d) In general, smaller atoms have larger ionization energies, and larger
electronegativity values.
e) There are no general trends among atomic radius, ionization energy, and
electronegativity.
41. Which of the following is true about an isoelectronic series?
a) The most positively charged species has the largest atomic radius, and the most
negatively charged species has the smallest atomic radius.
b) The noble gas has the largest atomic radius, and the most negatively charged
species has the smallest atomic radius.
c) The noble gas has the largest atomic radius, and the most positively charged
species has the smallest atomic radius.
d) The most negatively charged species has the largest atomic radius, and the most
positively charged species has the smallest atomic radius.
e) All of the species in an isoelectronic series have the same atomic radius.
42. Which of the following species have only single bonds in the Lewis structure?
a) C2H4
43.
b) CO32-
c) HCN
d) O3
e) None
How many lone pairs of electrons are around the central atom in ClF2+?
a) 0
b) 1
c) 2
d) 3
e) 4
44.
Which of the following species exhibits resonance?
a) NO2
+
b) NH4
c) CH4
d) OF2
e) At least two of the above species (a-d) exhibit resonance.
45.
Which of the following correctly pairs the molecule with the strongest
intermolecular attraction?
a) Li2O: dipole-dipole; F2: London dispersion; SO2: dipole-dipole
b) Li2O: dipole-dipole; F2: dipole-dipole; SO2: dipole-dipole
c) Li2O: ion-ion; F2: London dispersion; SO2: dipole-dipole
d) Li2O: dipole-dipole; F2: London dispersion; SO2: ion-ion
e) Li2O: ion-ion; F2: dipole-dipole; SO2: London-dispersion
CHEMISTRY 101
Mock Final Exam
Spring 2014
Page No. 9
----------------------------------------------------------------------------------------------------46-50. For each of the following molecules, choose the correct molecular geometry,
shape, and polarity.
GEOMETRY
46.
polar
polar
non-polar
non-polar
non-polar
trigonal planar
trigonal planar
linear
tetrahedral
linear
bent
bent
linear
bent
linear
non-polar
polar
non-polar
polar
polar
trigonal planar
tetrahedral
tetrahedral
tetrahedral
trigonal planar
trigonal planar
trigonal planar
tetrahedral
trigonal pyramid
bent
non-polar
non-polar
non-polar
polar
polar
trigonal bipyramid
octahedral
trigonal bipyramid
octahedral
trigonal bipyramid
trigonal bipyramid
square pyramid
trigonal bipyramid
square planar
T-shape
non-polar
polar
polar
non-polar
polar
trigonal bipyramid
trigonal bipyramid
trigonal planar
trigonal planar
linear
linear
trigonal planar
bent
bent
linear
non-polar
non-polar
non-polar
polar
non-polar
XeCl5+ (Xe is the central atom)
a)
b)
c)
d)
e)
50.
see-saw
tetrahedral
tetrahedral
square planar
square planar
Nitrogen triiodide (nitrogen is the central atom)
a)
b)
c)
d)
e)
49.
trigonal bipyramid
tetrahedral
tetrahedral
octahedral
trigonal bipyramid
Sulfur dioxide (sulfur is the central atom)
a)
b)
c)
d)
e)
48.
POLARITY
Sulfur tetrafluoride (sulfur is the central atom)
a)
b)
c)
d)
e)
47.
SHAPE
I3a)
b)
c)
d)
e)
[Answer on next page – don’t peek until you have finished!]
CHEMISTRY 101
Mock Final Exam
1. e
2. c
3. e
4. b
5. a
6. a
7. b
8. c
9. d
10. d
11. c
12. b
13. a
14. e
15. a
16. a
17. e
18. d
19. e
20. c
21. b
22. a
23. a
24. e
25. c
Spring 2014
Page No. 10
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
a
d
b
b
e
c
d
d
c
e
b
c
e
c
d
d
e
c
a
c
a
b
d
b
a