108-3rd Chem Exam (C)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) The basis of the VSEPR model of molecular bonding is __________.
A) regions of electron density in the valence shell of an atom will arrange themselves so as to maximize overlap
B) electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions C) hybrid orbitals will form as necessary to, as closely as possible, achieve spherical symmetry
D) regions of electron density on an atom will organize themselves so as to maximize s-character E) atomic orbitals of the bonding atoms must overlap for a bond to form
Answer: B
2)ClF3 has "T-shaped" geometry. There are __________ non-bonding domains in this molecule.
A) 2 B) 1 C) 3 D) 4 E) 0
Answer: A
3) The hybridization of the oxygen atom labeled y in the structure below is __________. The C-O-H bond angle is __________.
A) sp, 180° B) sp2, 109.5° C) sp, 90° D) sp3d2, 90° E) sp3, 109.5°
Answer: E
4)There are __________ bonds and __________ bonds in H3C-CH2-CH CH-CH2-C CH.
A) 14, 2 B) 16, 3 C) 10, 3 D) 12, 2 E) 13, 2
Answer: B
5) Based on molecular orbital theory, there are __________ unpaired electrons in the OF+ ion.
A) 1/2 B) 0 C) 1 D) 2 E) 3
Answer: D
6) Based on molecular orbital theory, the bond orders of the H H bonds in H2, H2+, and H2- are __________, respectively
A) 1, 0, and 1/2 B) 1, 1/2, and 1/2 C) 1, 0, and 0 D) 1, 2, and 0 E) 1, 1/2, and 0 Answer: B
7)Based on molecular orbital theory, the bond order of the N N bond in the N2 molecule is __________.
A) 0 B) 1 C) 2 D) 3 E) 5
Answer: D
8) The electron domain and molecular geometry of BrO2- is __________.
A) trigonal pyramidal, seesaw B) tetrahedral, trigonal planar C) tetrahedral, bent
D) trigonal pyramidal, linear E) trigonal planar, trigonal planar Answer: C
9) The molecular geometry of the right-most carbon in the molecule below is __________.
A) trigonal planar B) trigonal bipyramidal C) tetrahedral
D) T-shaped E) octahedral Answer: A
10) The bond angles marked a, b, and c in the molecule below are about __________, __________, and __________, respectively.
A) 109.5°, 120°, 109.5°
B) 109.5°, 90°, 120°
C) 120°, 120°, 109.5°
D) 120°, 120°, 90°
E) 90°, 90°, 90°
Answer: A
11)The molecular geometry of the SF6 molecule is __________, and this molecule is __________.
A) octahedral, nonpolar B) trigonal planar, nonpolar C) trigonal planar, polar D) trigonal bipyramidal, polar
E) trigonal pyramidal, polar Answer: A
12) Based on molecular orbital theory, the bond order of the N N bond in the N22+ ion is __________.
A) 2 B) 3 C) 0 D) 1/2 E) 1
Answer: A
13) Of the following, __________ appear(s) to gain mass in a magnetic field.
B2 N2 O2
A)N2 and O2 B)B2 and N2 C)B2 and O2 D)N2 only E)O2 only
Answer: C
14) In which of the following molecules is hydrogen bonding likely to be the most significant component of the total intermolecular forces?
A)CH4 B)C6H13NH2 C)C5H11OH D)CO2 E)CH3OH
Answer: E
15)What types of intermolecular forces exist between HI and H2S?
A) dispersion forces and dipole-dipole B) dipole-dipole and ion-dipole
C) dispersion forces, dipole-dipole, and ion-dipole D) dispersion forces, dipole-dipole, and ion-dipole
E) dispersion forces, hydrogen bonding, dipole-dipole, and ion-dipole Answer: A
16) Which statements about viscosity are true?
(i) Viscosity increases as temperature decreases.
(ii) Viscosity increases as molecular weight increases.
(iii) Viscosity increases as intermolecular forces increase.
A) (i) only B) (ii) and (iii) C) (i) and (iii) D) none E) all Answer: E
17) Based on the following information, which compound has the strongest intermolecular forces?
Substance Hvap (kJ/mol)
Argon (Ar) 6.3
Benzene (C6H6) 31.0
Ethanol (C2H5OH) 39.3
Water (H2O) 40.8
Methane (CH4) 9.2
A) Benzene B) Water C) Methane D) Ethanol E) Argon
Answer: B
18) The slope of a plot of the natural log of the vapor pressure of a substance versus 1/T is __________.
A) - Hvap B) - Hvap
R C) -1
Hvap D) 1
Hvap E) Hvap
Answer: B
19) The strongest interparticle attractions exist between particles of a __________ and the weakest interparticle attractions exist between particles of a __________.
A) solid, liquid B) liquid, gas C) solid, gas D) gas, solid E) liquid, solid Answer: C
20) Which one of the following exhibits dipole-dipole attraction between molecules?
21) Of the following, __________ has the highest boiling point.
A)O2 B)N2 C)Br2 D)H2 E)Cl2
Answer: C
22) Which of the following is most likely to exhibit liquid-crystalline behavior?
A) CH3CH2CH2CH2CH2- Na+
B)
C)CH3CH2CH2CH2CH2CH2CH2CH3 D)
E)CH3CH2-C(CH3)2-CH2CH3
Answer: D
23) The reaction of 50 mL of Cl2 gas with 50 mL of C2H4 gas via the equation:
Cl2 (g) + C2H4 (g) C2H4Cl2 (g)
will produce a total of __________ mL of products if pressure and temperature are kept constant.
A) 100 B) 125 C) 50 D) 150 E) 25
Answer: C
24) The volume of a sample of gas (2.49 g) was 752 mL at 1.98 atm and 62 °C. The gas is __________.
A)NH3 B) Ne C)SO3 D)NO2 E)SO2
Answer: D
25)The density of NO2 in a 4.50 L tank at 760.0 torr and 25.0 °C is __________ g/L.
A) 1.68 B) 1.88 C) 3.27 D) 1.64 E) 9.30
Answer: B
26) Of the following gases, __________ will have the greatest rate of effusion at a given temperature.
A)NH3 B) Ar C)CH4 D) HBr E) HCl
Answer: C
27) The pressure exerted by a column of liquid is equal to the product of the height of the column times the gravitational constant times the density of the liquid, P = ghd. How high a column of water (d = 1.0 g/mL) would be supported by a pressure that supports a 713 mm column of mercury (d = 13.6 g/mL)?
A) 1.2 × 104 mm B) 9.7 × 103 mm C) 713 mm D) 52 mm
E) 14 mm Answer: B
28) The volume of an ideal gas is zero at __________.
A) -45 °F B) -273 °C C) -363 K D) 0 °C E) -273 K
Answer: B
29) Standard temperature and pressure (STP), in the context of gases, refers to __________.
A) 273.15 K and 1 atm B) 298.15 K and 1 atm C) 298.15 K and 1 torr D) 273.15 K and 1 pascal
E) 273.15 K and 1 torr Answer: A
30) Which one of the following gases would deviate the least from ideal gas behavior?
A)CH3Cl B) Ne C) Kr D)CO2 E)F2
Answer: B
31) Which noble gas is expected to show the largest deviations from the ideal gas behavior?
A) argon B) neon C) xenon D) krypton E) helium
Answer: C
32) The process of doping can produce a __________ which can greatly __________ intrinsic conductivity.
A) allotrope, diminish B) non-metal, increase C) non-metal, decrease
D) p-type semiconductor, decrease E) n-type semiconductor, increase Answer: E
33) The formation of a condensation polymer generally involves __________.
A) the mixing of sulfur with an addition polymer B) the elimination of a small molecule
C) the addition of a plasticizer
D) the formation of significant crosslinking E) the vaporization of a plasticizer
Answer: B
34) Which of the following is not classified as a nanomaterial?
A) buckminsterfullerene B) isoprene
C) carbon nanotubes D) graphene
E) All of the above are classified as nanomaterials Answer: B
35) Which of the following is not a type of solid?
A) supercritical B) molecular C) metallic D) ionic
E) covalent-network Answer: A
36) The scattering of light waves upon passing through a narrow slit is called __________.
A) diffusion B) adhesion C) incidence D) grating E) diffraction
Answer: E
37) If the electronic structure of a solid substance consists of a valence band that is completely filled with electrons and there is a large energy gap to the next set of orbitals, then this substance will be a(n) __________.
A) conductor B) nonmetal C) semiconductor D) insulator
E) alloy Answer: D
38) What fraction of the volume of each corner atom is actually within the volume of a face-centered cubic unit cell?
A) 1 B) 1/2 C) 1/4 D) 1/8 E) 1/16
Answer: D
39) NaCl crystallizes in a face-centered cubic cell. What is the total number of ions (Na+ ions and Cl- ions) that lie within a unit cell of NaCl?
A) 4 B) 5 C) 8 D) 2 E) 6
Answer: C
40) Inorganic compounds that are semiconductors have an average of __________ valence electrons.
A) 5 B) 4 C) 2 D) 3 E) 1
Answer: B
