Part 4. Bonding
26. A compound consisting of an element having a
low ionization potential and a second element
having a high electron affinity is likely to have
(A) covalent bonds.
(B) metallic bonds.
(C) coordinate covalent bonds,
(D) ionic bonds.
(A)
(B)
(C)
(D)
O
(A)
27. An acceptable Lewis dot structure for N2O is
•• ••
•• ••
O N N••
•• ••
••
••••
O N N••
31. Which best represents hydrogen bonding in
liquid methanol (CH3OH)?
•• ••
O N N••
•• ••
O N N••
28. Solid potassium fluoride consists of potassium
ions and fluoride ions. What is the best
experimental evidence for this statement?
(B)
H
O
C H
H
C
H
H
O
O
H
C
H
H
H
H
H
C H
H
H
(C)
H
H H
H
C
C
H
O
O
H
H
H H
(B) A water solution of potassium fluoride can
be electrolyzed.
(D) Potassium fluoride is classified as a regular
or cubic crystal.
H
H
(A) Molten potassium fluoride conducts an
electric current.
(C) Potassium and fluorine have electron
configurations best suited to form ions that in
turn form a more stable solid than atoms of
each.
H
(D)
H
C
H
O
H
H
H
C O
H
32. Consider the boiling point of a series of
hydrogen compounds.
(E) When the solid is heated the kinetic energy
becomes large enough to overcome the
directive forces that hold the components
together.
29. In which pair of compounds should the first
member be more covalent than the second
member?
(A) TlCl, TlCl3
(C) LiF, BF3
(B) SnI4, SnF4
(D) SnF4, CF4
30. The compound of which two elements is most
likely to involve covalent bonding?
Electronegativities of
Unknown Elements
Q 0.9
X 3.0
R 1.0
Z 4.0
T 2.8
(A) Q and Z
(B) R and T
(C) T and X
(D) R and X
(E) R and Z
The abnormally high boiling point for
water is due to
(A) extensive hydrogen bonding.
(B) its low dipole moment.
(C) the extreme stability of the compound.
(D) the high electronegativity of hydrogen.
33. Which contains both covalent and ionic bonds?
(A) NH4NO3
(B) NF3
(C) BaCl2
(D) CH2O
34. According to modern bonding theory the
number of sigma (σ) and pi (π) bonds in the
ethylene molecule H2C=CH2 is
(A) 1 σ and 4 π
(B) 1 σ and 5 π
(C) 1 π and 4 σ
(D) 1 π and 5 σ
(E) 2 π and 4 σ
(A) At STP the weight of 22.4 L of hydrogen
sulfide gas is 34 g, of which 32 g is sulfur.
(B) Sulfur and hydrogen atoms combine in a
ratio of two to one.
(C) Free hydrogen gas consists of H2 molecules,
but sulfur is solid.
(D) When hydrogen sulfide is burned in air or
oxygen, H2O and SO2 are formed.
(E) The sulfur atom has six electrons in its outer
level, and obtains the two electrons needed for
a stable arrangement by combining with two
hydrogen atoms.
36. Which is the best Lewis structure for NOCl?
(B)
•• ••
•••• •• •
O N Cl
•••••• •• •
••••
•• •••••• •• ••
O N Cl
••
(C)
•• ••
••••• •• •
O N Cl
••• •• •
(D)
37. Which is the least significant contributing
structure to the resonance hybrid of the nitrate
ion?
–
•• ••
O ••
(A)
(C)
N
N
••
O ••
••
••
O••
••
42. Which is planar?
(A) NH3
(B) SO32–
(C) CO32–
(D) H3O+
43. Which concept describes the formation of four
equivalent, single, covalent bonds by carbon in
compounds like methane, CH4?
(A) hydrogen bonding
(B) hybridization
(C) sigma bonding
(D) coordinate covalent bonding
44. Sulfur dioxide can be described by two
resonance structures. This implies that
(A) the two bonds in SO2 are of equal length, and
the electronic distribution in the two SO bonds
is identical.
(B) the single bond is longer than the double
bond and the electronic distribution in the two
SO bonds is different.
(C) an electron pair in the SO2 molecule
alternates back and forth between the two
sulfur–oxygen electron pairs so that the two
different bonds seem to exchange positions.
(D) the SO2 molecule revolves so that the two
different bonds seem to exchange positions.
(D)
Part 5. Structure
38. The fact that H2O has a dipole moment
suggests that the water molecule is
(A) dimeric.
(B) bent.
(C) square planar.
(D) rectangular planar.
(C) symmetrical.
(D) nonpolar.
39. Which pair is geometrically similar?
(A) SO2 and CO2
(C) CO2 and OF2
(B) PH3 and BF3
(D) SO2 and O3
:
•• ••
O
••
(C) trigonal pyramidal.
(D) tetrahedral.
(A) trigonal pyramidal.
(B) tetrahedral.
:
(B)
•• O
••
–
•• O ••
(A) octahedral.
(B) trigonal planar.
41. The geometry for SeF3+ is
35. The best theoretical explanation for the
assertion that the formula of hydrogen sulfide gas
is H2S is that
(A)
40. The shape that most closely describes the NF3
molecule is
45. The molecule : O C N H has been detected
in gas clouds between stars. The predicted C—N—H
bond angle is about
(A) 60°
(C) 109°
(B) 90°
(D) 120°
46. Which bond angle, (θ), would result in the
greatest dipole moment for a triatomic molecule?
(A) θ = 90°
(C) θ = 150°
(B) θ = 120°
(D) θ = 180°
Part 6. Periodic Properties
47. The elements X, Y, and Ζ form these
compounds: XCl4, X Z2, and YO. What formula
would you predict for the compound formed
between Y and Z? (Assume normal oxidation states
of Cl and O.)
(A) YZ
(B) YZ 2
(C) Y 2Z
(D) YZ3
51. The sizes of metal atoms
(A) generally increase progressively from bottom
to top in a group in the periodic table.
(B) generally increase progressively from top to
bottom in a group in the periodic table.
(C) generally increase progressively from left to
right in a period.
(D) are smaller than those of the corresponding
ions.
(E) do not change upon losing electrons.
52. Predict which element would have the largest
difference between its first and second ionization
energies.
(A) sodium
(B) silicon
(C) phosphorus
(D) magnesium
53. Which element has the highest first ionization
energy?
(A) Na
(C) Cs
48. Which element in this periodic table will form
an oxide Y2O3?
(B) F
(D) I
54. A neutral atom will have the lowest ionization
potential when its electron configuration is
(A) 1sl
(B) ls22s22p2
(D) ls22s22p6
(E) 1s22s22p63s1
(C) ls22s22p5
(A) E
(D) L
(B) G
(E) R
(C) J
49. In which pair of particles is the first member
larger than the second member?
(A) Li+ ; Be2+
(B) Li+ ; Li
(C) Li+ ; Na+
(D) Be ; Mg
50. Which ion has the largest radius?
(A) Te2–
(C) Rb+
(B) F–
(D) Mg2+
55. Five elements, X, Y, Z, J, and Q, have the
indicated electron configurations, starting with the
innermost shell. Which is the most metallic?
(A) X — 2, 8, 2
(B) Y — 2, 8, 8
(C) Z — 2, 8, 8, 2
(D) J — 2, 8, 8, 4
(E) Q — 2, 8, 8, 7
Answers
26.
27.
28.
29.
30.
D
B
A
B
C
36.
37.
38.
39.
40.
B
A
B
D
C
46.
47.
48.
49.
50.
A
A
C
A
A
31.
32.
33.
34.
35.
C
A
A
D
E
41.
42.
43.
44.
45.
A
C
B
A
D
51.
52.
53.
54.
55.
B
A
B
E
C