DC Chem Practice Final
1. How many significant figures are in the number 2.030 x 10 3 cm?
a. One
b. Two
c. Three
d. Four
2. How many valence electrons (total) are there in one ion of carbonate?
a. 22
b. 18
c. 24
d. 12
e. 26
3. If the total pressure of a mixture of 0.35 mol Ar (g) and 0.22 mol Ne (g) is 1.77 atm, calculate the partial
pressure of Ar (g) in the mixture.
a. 0.61 atm
b. 0.39 atm
c. 1.1 atm
d. 0.68 atm
e. not enough information is provided
4. Consider the following balanced chemical equation:
S(s) + O2(g) ----> SO2(g)
If 2 mol S(s) and 8 mol O2(g) are provided, which is the limiting reagent?
a. S(s)
b. O2(g)
c. SO2(g)
d. Neither S(s) nor O2(g) is limiting
e. not enough information is provided
5. Ammonia can be prepared according to the following equation: N2(g) + 3H2(g) ----> 2NH3(g). If you
begin with 4.70 L of nitrogen gas, what volume of hydrogen gas must be provided to completely consume
all of the nitrogen gas that has been provided?
a. 1.57 L
b. 4.70 L
c. 14.1 L
d. 2.35 L
e. 9.40 L
6. Choose the substance below that is the best example of a strong acid:
a. ammonia
b. hydrofluoric acid
c. sodium hydroxide
d. nitric acid
e. hypobromous acid
7. According to the phase diagram for water on page 495 (Figure 12.33) of your text, at which of the
following temperature and pressure measurements is water likely to be a vapor?
a. 1.5 atm; 1 oC
b. 0.005 atm; 1 oC
c. 0.007 atm; 0.01 oC
d. Two of the other choices are correct
e. None of the other choices are correct
8. Which of the following particles or rays has no mass?
a. electron
b. gamma
c. alpha
d. beta
e. neutron
9. What is the oxidation number for sulfur in HSO4-?
a. -2
b. +8
c. +1
d. +4
e. +6
10. The correct IUPAC name for CuCO3 is:
a. copper(II) carbonic acid
b. copper(II) carbonate
c. cuprous carbonate
d. copper(I) carbonate
e. cupric carbonite
11. Which of the following molecules is polar?
a. HBr
b. SiH4
c. CH4
d. BH3
e. None of the choices are examples of polar molecules
12. Selenium is best classified as a(n):
a. chalcogen
b. alkali metal
c. gas
d. metalloid
e. more than one of the other choices are correct
13. How much heat is required to raise the temperature of a 27.2 g sample of liquid water from an initial
temperature of 29.5 oC to a final temperature of 83.4 oC?
a. -6.13 kJ
b. +6.13 kJ
c. +81.3 J
d. -6.13 J
e. +6.13 J
14. A photon with which of the following frequencies is expected to have the highest energy?
a. 1.2 x 109 Hz
b. 1.2 x 1012 Hz
c. 3.8 x 104 Hz
d. 1.2 Hz
e. 1.2 x 1020 Hz
15. The molecular geometry for XeBr2 is predicted to be:
a. T-shaped
b. Linear
c. Trigonal pyramidal
d. Trigonal bipyramidal
e. See-saw
16. Which of the following substances is predicted to exhibit hydrogen bonding?
a. H2Se
b. CH2Cl2
c. CH3OH
d. HI
e. O2
17. Which of the following ions is predicted to be paramagnetic?
a. Cr3+
b. Na+
c. Cu2+
d. Zn2+
e. two of the other choices are correct
18. The total volume of 0.150 mol of N2(g) and 0.100 mol of O2(g) at 0.00 oC at 1.00 atm pressure is:
a. 0.00 L
b. 5.60 L
c. 0.250 L
d. 22.4 L
e. 11.2 L
19. What is the predicted typical charge on an aluminum ion?
a. 0
b. +1
c. -1
d. +3
e. -3
20. What is the bond order for the Li-Li bond in the Li22- ion?
a. 0
b. 0.5
c. 1
d. 1.5
e. 2
21. Which of the following statements is incorrect?
a. A bonding molecular orbital is lower in energy than the atomic orbitals from which it was formed.
b. A set of sp2 hybrid orbitals has an angle of 120o between each orbital.
c. The Heisenberg Uncertainty Principle says that you cannot simultaneously know both the position
and momentum of an electron.
d. In a hydrogen atom, the transition n = 5 ----> n = 4 results in the absorption of a photon with a
longer wavelength than the transition n = 2 ----> n = 1.
e. Delocalized electrons are well-described by Molecular Orbital Theory.
22. At 25.0 oC, which of the following collections of gases is predicted to contain particles with the highest
average velocity?
a. 1.0 L of argon as a pressure of 1.0 atm
b. 1.0 L of He at a pressure of 0.5 atm
c. 16.0 g of CH4 at a pressure of 1.0 atm
d. 25 neon atoms at a pressure of 1.50 mmHg
e. All of the gases mentioned in the other choices have the same velocity under the given conditions.
23. What is the pressure of a 32.0 g sample of O2(g) at at temperature of 29.0 oC in a 30.0 L flask?
a. 0.826 atm
b. 0.0826 atm
c. 0.0793 atm
d. 0.0821 atm
e. 0.821 atm
24. The set of quantum numbers n = 4, l = 1 best describes a:
a. 2s orbital
b. 4d orbital
c. 4p orbital
d. 3p orbital
e. 5p orbital
25. The maximum total number of electrons that may occupy one 5d orbital is:
a. 0
b. 1
c. 2
d. 6
e. 10
26. Calculate the enthalpy change for the transformation: S(rhombic) ----> S(monoclinic) from the
following information:
S(rhombic) + O2(g) ----> SO2(g) ΔH = -296.06 kJ
S(monoclinic) + O2(g) ----> SO2(g) ΔH = -296.36 kJ
a. -0.30 kJ
b. +0.30 kJ
c. -592.42 kJ
d. +592.42 kJ
e. none of the other choices are correct
27. Which of the following is a physical change?
a. Iron melting
b. Alcohol burning
c. Steam condensing
d. two of the other choices are correct
e. none of the other choices are correct
28. Which of the following compounds is predicted to be soluble in water?
:
a. NH4I
b. MgI2
c. KI
d. CsI
e. All of the compounds represented in the other choices are expected to be soluble in water
29. As the temperature of a gas goes down when the volume and amount of the gas are held constant, what
would you expect to happen to the pressure of the gas?
a. The pressure of the gas should increase
b. The pressure of the gas should not change
c. The pressure of the gas should decrease
d. Not enough information is provided to draw a conclusion
30. What is the concentration of a potassium nitrate solution prepared by diluting 50.0 mL of a 0.750 M
solution of potassium nitrate to a final volume of 0.500 L?
a. 0.0750 M
b. 0.500 M
c. 0.750 M
d. 7.50 M
e. 0.00750 M
31. The electron configuration for an oxygen atom is best described as:
a. 1s22s22p2
b. [He]2s22p2
c. 1s22s23p4
d. 1s22s22p4
e. 1s22s23p2
32. Which of the following best describes the correct Lewis electron dot structure for BF 3?
a. 10 valence electrons, three bonds, zero lone pair electrons on central B atom
b. 22 valence electrons, four bonds, zero lone pair electrons on central B atom
c. 24 valence electrons, 3 bonds, zero lone pair electrons on central B atom
d. 24 valence electrons, 3 bonds, zero lone pair electrons on central F atom
e. 26 valence electrons, 3 bonds, one lone pair of electrons on central B atom
33. Consider the reaction Fe2O3(s) + 3CO(g) ----> 2Fe(s) + 3CO2(g)
If 1.5 moles of iron(III) oxide and 3 moles of carbon monoxide are combined, what is the theoretical yield
of iron in moles?
a. 1 mol
b. 3 mol
c. 1.5 mol
d. 0.5 mol
e. 2 mol
34. The intermolecular force that governs the dissolution of oxygen in water is:
a. ion-dipole
b. dipole-dipole
c. dipole-induced dipole
d. hydrogen bonding
e. dispersion forces only
35.
Which of the following substances is predicted to exhibit dipole-dipole forces, but not hydrogen bonding?
a. CH3OH
b. HBCl2
c. CH2Br2
d. none of the other choices are correct
e. two of the other choices are correct
36. Which of the following statements is incorrect?
a. Homogeneous matter could be either a pure substance or a mixture.
b. Elements can be combined chemically make compounds.
c. A heterogeneous mixture could be composed of both elements and compounds.
d. A pure substance is not heterogeneous.
e. Homogeneous mixtures must contain elements
37. Which of the following substances would you expect to have the lowest vapor pressure at room
temperature?
a. diethyl ether, CH3CH2OCH2CH3(l)
b. Liquid mercury, Hg(l)
c. Liquid water, H2O(l)
d. Ethanol (l)
e. Not enough information is provided
38. Under constant-temperature conditions, a sample of argon gas initially at 1.20 atm and 0.95 L is
allowed to expand to a volume of 1.50 L. What is its final pressure?
a. 2.1 atm
b. 1.9 atm
c. 4.2 atm
d. 1.1 atm
e. 0.76 atm
39. Which of the following cations is predicted to have the smallest atomic radius?
a. Rb+
b. Sr2+
c. Cs+
d. Ba2+
e. They all have the same atomic radius
40. Which of the following is NOT a state function?
a. heat
b. change in elevation
c. work
d. two of the other choices are correct
e. change in volume
41. One mole of a certain compound is found to contain 1.204 x 10 24 O atoms, 4.032 g H atoms, and 2 mol
C atoms. Propose the molecular formula and the empirical formula for this compound.
42. An unknown compound (0.6825 g) containing Ag+ ions is dissolved in water. After the addition of
sufficient CaCl2(aq) to the solution containing Ag+ ions, all of the Ag+ ions are precipitated as 0.6295 g of
AgCl(s). Calculate the percent by mass of Ag+ in the unknown compound.
43. Calculate the amount of heat in kJ needed to convert 336 g ice at -10.0 oC to steam at 108.5 oC.
44. A certain person runs a mile in 9.00 minutes. Calculate the person’s speed in centimeters/second.
45. A steel cylinder is filled with N2(g) to a pressure of 4,589 mmHg. Calculate the density of the N2(g) in
the cylinder at 29.82 oC.
46. Balance the following equation and calculate the volume of air needed (in L) to completely combust
0.0576 mol C2H5OH(l). The process is occurring at 34.4 oC and 1.004 atm. Assume that the air is 21.0%
oxygen gas by volume.