Chapter 10 Practice: Organic
AP Chem
1984 Multiple Choice
77. Which of the following compounds exhibits optical isomerism?
1989
31. The structural isomers C2H5OH and CH3OCH3 would be expected to have the same values for
which of the following? (Assume ideal behavior.)
(A) Gaseous densities at the same temperature and pressure
(B) Vapor pressures at the same temperature
(C) Boiling points
(D) Melting points
(E) Heats of vaporization
1994
43. Which of the following pairs of compounds are isomers?
(A)
(B)
CH3−CH2−CH2−CH3
CH3−CH−CH3
CH3
and
CH3−CH−CH3
and
CH2−CH=CH2
CH3
CH3
O
(C)
CH3−O−CH3
and
CH3−C−CH3
(D)
CH3−OH
and
CH3−CH2−OH
(E)
CH4
and
CH2=CH2
1999
29. The organic compound represented to the right is an example of
(A) an organic acid
(B) an alcohol
(C) an ether
(D) an aldehyde
(E) a ketone
O
||
CH3 – C – CH2 – CH3
32. Types of hybridization exhibited by the C atoms in propene, CH3CHCH2, include which of the following?
I. sp
II. sp2
III. sp3
(A) I only
(B) III only
(C) I and II only
(D) II and III only
(E) I, II, and III
1
2002
1. Which of the following structural formulas represents an isomer of the compound that has the structural
formula represented above?
Free Response Questions
1981 D
Assume that you have two different gases that you know are not cyclic (i.e. not ring) compounds, each with the
following elementary analysis: C = 85.7%, H = 14.3%. Each gas has a molecular weight of 56.1.
(a) What is the molecular formula for the compounds?
(b) Draw the structural formulas for the four possible noncyclic isomers with this molecular formula.
(c) In the presence of an appropriate catalyst, both gases add hydrogen. The hydrogenated products are
identical, their molecular weight is 58. Which of the structures you drew to answer (b) can definitely be
eliminated on the basis of this additional information?
1998 D
Answer each of the following using appropriate chemical principles.
(c) Dimethyl ether, H3C-O-CH3, is not very soluble in water. Draw a structural isomer of dimethyl ether that is
much more soluble in water and explain the basis of its increased water solubility.
In each case, justify your choice.
2003 D
Using the information in the table above, answer the following
questions about organic compounds.
(a) For propanone,
(i) draw the complete structural formula (showing all
atoms and bonds);
(ii) predict the approximate carbon-to-carbon-to-carbon
bond angle.
Compound
Name
Compound
Formula
∆H˚vap
(kJ mol-1)
Propane
CH3CH2CH3
19.0
Propanone
CH3COCH3
32.0
1-propanol
CH3CH2CH2OH
47.3
(b) For each pair of compounds below, explain why they do not have the same value for their standard heat of
vaporization, ∆H˚vap. (You must include specific information about both compounds in each pair.)
(i) Propane and propanone
(ii) Propanone and 1-propanol
H

H⎯C⎯C≡C⎯H
(c) Draw the complete structural formula for an isomer of the molecule you drew in, part (a) (i).
H
(d) Given the structural formula for propyne to the right,
(i) indicate the hybridization of the carbon atom indicated by the arrow in the structure
above;
(ii) indicate the total number of sigma (σ) bands and the total number of pi (π) bonds in the molecule
2
2005 Form B
8. Use principles of atomic structure, bonding, and intermolecular forces to answer the following questions.
Your responses must include specific information about all substances referred to in each part.
a) Draw a complete Lewis electron-dot structure for the CS2 molecule. Include all valence electrons in
your structure.
b) The carbon-to-sulfur bond length in CS2 is 160 picometers. Is the carbon-to-selenium bond length in
CSe2 expected to be greater than, less than, or equal to this value? Justify your answer.
c) The bond energy of the carbon-to-sulfur bond in CS2 is 577 kJ mol-1. Is the bond energy of the carbonto-selenium bond in CSe2 expected to be greater than, less than, or equal to this value? Justify your
answer.
d) The complete structural formulas of propane, C3H8, and methanoic acid, HCOOH, are shown above. In
the table below, write the type(s) of intermolecular attractive force(s) that occur in each substance.
e) Use principles of intermolecular attractive forces to explain why methanoic acid has a higher boiling
point than propane.
3
Chapter 10: Additional Organic Chemistry Practice Problems
(A)
R−C=O
⏐
H
(B)
(C)
R−C=O
⏐
O−R’
R−O−H
(D)
(E)
R−C=O
⏐
O−H
R−C=O
⏐
R’
Use the above choices for the next five questions. Identify the functional group indicated.
1. alcohol
2. carboxylic acid
3. ketone
4. ester
5. aldehyde
6. Each of the following illustrates a pair of isomers EXCEPT
H H H
(A)
(B)
(C)
H−C−C−C−Cl
H H H
and
H−C−C−C−Br
(D)
H
Br
H H H
H H H
C=C
Br
H
H H H
H H
H
H−C−C−C−OH
and
H
H−C−C⎯C−H
H H H
H OH H
H H H
H
H−C−C−C−OH
H H H
and
(E)
H
H
C=C
Br
Br
and
H H H H
H
H−C−C=C−H
and
H−C−C=C−C−H
H CH3
H
H
H H
H−C−O−C−C−H
H
H H
7. Which organic compound is a weak electrolyte?
(A) C2H6
(B) CH3Cl
(C) HCOOH
(D) CH3OH
(E) C6H12O6
8. In the fermentation of plant materials, which kind of compound is converted to alcohol?
(A) acid
(D) carbohydrate
(B) enzyme
(E) hydrocarbon
(C) carbonate
9. Which of the five compounds listed below has a molar mass that is different from the other four?
(A) 2-butanol
(D) 2-methyl-2-propanol
(B) 2-propanol
(E) 2-methyl-1-propanol
(C) diethyl ether
10. Which of the following compounds represents the greatest degree of oxidation?
(A) carboxylic acid
(D) aldehyde
(B) ketone
(E) hydrocarbon
(C) alcohol
4