ORGANIC CHEMISTRY, STRUCTURE and
BONDING
Note: For all questions referring to solutions,
assume that the solvent is water unless otherwise
stated.
9. Which of the following compounds is ionic and
contains both sigma and pi covalent bonds?
(A) Fe(OH)3
(C) H2S
(E) NaCN
(B) HClO
(D) NO2
1. Which of the following molecules has a dipole
moment of zero?
(A) H2S
(B) NO
(C) SO2
(D) NH3
(E) C6H6 (benzene)
10.
CCl4, CO2, PCl3, PCl5, SF6
Which of the following does not describe any of the
molecules above?
(A) Linear
(D) Tetrahedral
(B) Octahedral
(E) Trigonal pyramidal
(C) Square planar
2. The electron–dot structure (Lewis structure) for
which of the following molecules would have two
unshared pairs of electrons on the central atom?
(A) H2S
(B) NH3
(C) CH4
(D) HCN
(E) CO2
11. The SbCl5 molecule has trigonal bipyramid
structure. Therefore, the hybridization of Sb orbitals
should be
(A) sp2
(C) dsp2
(E) d2sp3
3
3
(B) sp
(D) dsp
3. Molecules that have planar configurations
include which of the following?
I. BCl3
II. CHCl3
III. NCl3
(A) I only
(B) III only
(C) I and II only
(D) II and III only
(E) I, II, and III
12. For which of the following molecules are
resonance structures necessary to describe the
bonding satisfactorily?
(A) H2S
(C) CO2
(E) PF3
(B) SO2
(D) OF2
4. In a molecule in which the central atom exhibits
sp3d2 hybrid orbitals, the electron pairs are directed
toward the corners of
(A) a tetrahedron
(B) a square-based pyramid
(C) a trigonal bipyramid
(D) a square
(E) an octahedron
Questions 5-7 refer to the following diatomic species.
(A) Li2
(B) B2
(C) N2
(D) O2
(E) F2
_C_5. Has the largest bond–dissociation energy
_D_6. Has a bond order of 2
_C_7. Contains 1 sigma () and 2 pi () bonds
8.
The Lewis dot structure of which of the
following molecules shows only one unshared pair
of valence electrons?
(A) Cl2
(C) NH3
(E) H2O2
(B) N2
(D) CCl4
13. Which one of the following pairs of compounds
is isomeric?
CH3 CH CH3
(A)
CH3 CH2
CH2
CH3
CH3 C CH2
CH3 CH CH3
CH3
(B)
CH3
and
CH3
and
O
(C)
CH3
O CH3
(D)
CH3 OH
and
and CH3 C CH3
CH3 CH2 OH
(E) CH4 and CH2 CH2
Questions 14-17 ask you to classify a molecule into
one of the following categories.
(A) aldehyde
(B) ketone
(C) alcohol
(D) ether
(E) carboxylic acid
_C_14. CH3CH2OH
_E_15. CH3CH2CH2COOH
25. Which of the following formulas can represent
more than one compound?
I
CH4O
II
C2H2Cl2
III
H2CO2
IV
C2H6O
(A) I, II and III
(B) I and II
(C) II and IV
(D) III
(E) IV
(F) II
_A_16. CH3CH2CHO
26. Which one of these things is not like the others?
_D_17. CH3CH2OCH3
18. Which of the following has a zero dipole
moment?
(A) HCN
(C) SO2
(E) PF5
(B) NH3
(D) NO2
19. The geometry of the SO3 molecule is best
described as
(A) trigonal planar
(D) bent
(B) trigonal pyramidal (E) tetrahedral
(C) square pyramidal
CH3
CH3 CH2 CH CH2 CH CH2
H3C CH CH3
(A)
CH3
21. Which of the following molecules has the
shortest bond length?
(A) N2
(C) Cl2
(E) I2
(B) O2
(D) Br2
22. The approximate OSO angle in the SO2
molecule is:
(A) 60
(B) 90
(C)109
(D) 120
(E)180
23. The hybridization of the central atom, S, in SF4
is:
(A) sp
(B) sp2
(C) sp3
3
3
2
(D) sp d
(E) sp d
24. Which species is most likely to be planar?
(A) NH4+
(B) CO32—
(C) SO32—
(D) ClO3
(E) none of the above
CH3
CH3 CH CH CH2 CH CH2 CH3
CH2CH3
(B)
H3C CH2
CH2 CH3
CH3 CH CH CH2
CH CH3
CH3
(C)
20. Pi () bonding occurs in each of the following
species EXCEPT
(A) CO2
(C) CN–
(E) CH4
(B) C2H4
(D) C6H6
CH3
CH3
CH2 CH3
CH CH2 CH CH CH3
(D) CH2 CH3
CH3
CH2 CH3
CH3 CH2 CH CH CH2 CH CH3
CH3
(E)
CH3
27.
I2(g) + 3 Cl2(g)  2 ICl3(g)
According to the data in the table below, what is the
value of ° for the reaction above?
Bond
I–I
Cl–Cl
I–Cl
Average Bond Energy
(kilojoules/mole)
150
240
210
(A) –870 kJ (B) –390 kJ (C) +180kJ
(D) +390 kJ (E) +1,260 kJ
28. Which one of the following compounds
exhibits cis/trans isomerism?
(A) CH3CH=CH2
(B) CH2=CHCH=CH2
(C) (CH3)2C=CHCH3
(D) (CH3)2C=C(CH3)2
(E) CH3CH=CHCH3
Questions 29 – 31 ask you to classify a molecule
into one of the following categories.
(A) aldehyde (B) ketone
(C) alcohol
(D) ether (E) carboxylic acid (F) ester
_F_29. CH3COOCH3
37. Which list is arranged in order of increasing
O-N-O bond angle?
(A) NO2– < NO2 < NO2+
(B) NO2 < NO2– < NO2+
(C) NO2+ < NO2 < NO2–
(D) NO2 < NO2+ < NO2–
(E) NO2– < NO2+ < NO2
38. Which species is a free radical?
(A) N2O
(B) NO2–
(D) NO
(E) N2O4
(C) NO2+
Questions 39 - 42 refer to the following answers:
(A) Sigma bonding
(B) Pi bonding
(C) d orbitals
(D) Resonance
(E) Hybridization
_B_30. CH3COCH2CH3
_C_31. CH3CH(OH)CH2CH3
BH3, CH4, PCl5, H2O, HF, H2
32. How many of the above possess dipole
moments?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
33. What is the molecular structure for NI3?
(A) linear
(B) tetrahedral (C) square
(D) octahedral (E) none of the above
34. Which of the following groups contains no
ionic compounds?
(A) HCN, NO2, Ca(NO3)2
(B) PCl5, LiBr, Zn(OH)2
(C) KOH, CCl4, SF4
(D) NaH, CaF2, NaNH2
(E) CH2O, H2S, NH3
35. Which bond is most likely to be nonionic?
(A) Ti-O
(B) Cs-F
(C) Li-I
(D) Ge-S
(E) Sr-N
36. Which of the following is the most covalent?
(A) CsF (B) KCl (C) LiI (D) CsI (E) LiF
_B_39. Lies off the internuclear axis.
_D_40. Used to explain why all 6 C–C bonds in
benzene are equal in length.
_E_41. Used to explain why all four C–H bonds in
methane are equivalent.
_C_42. Involved in expanding the bonding
electrons beyond an octet.