Portage Learning Chem 219 Principles of
Organic Chemistry Module 3 Exam
1. Characterize each of the following objects as being chiral or achiral
A. Drill bit
B. Screw
C. Screwdriver
, D. Boot
Carrot:
Answer
A. Chiral
B. Chiral
C. Achiral
D. Chiral
E. Achiral
Expert Rationale:
- A drill bit and a screw are classic examples of objects that display handedness (i.e., chirality) because
their helical threads can exist in two non-superimposable mirror image forms (right- or left-handed).
- A screwdriver (with a simple cylindrical shaft and symmetric handle) displays bilateral symmetry and
is achiral.
- A standard boot (not a symmetric galosh) fits only one foot, so it is chiral—left and right boots are
non-superimposable.
- A carrot, if symmetric and not twisted, is typically achiral, though some biological carrots may exhibit
subtle twists (rarely relevant in general chemistry context).
2. Characterize each of the following objects as being chiral or achiral:
a. Pencil
b. Wine Glass
c. Baseball Glove
d. Orchestra Conductors' Baton
Scissors:
Answer
a. achiral
, b. achiral
c. chiral
d. achiral
e. chiral
Expert Rationale:
- A pencil, lacking features like a grip or label, is a uniform cylinder and thus achiral—its
mirror image is superimposable.
- A wine glass (without decorations or asymmetry), due to its radial symmetry about the
stem, is achiral.
- A baseball glove is purposely designed to fit either the left or right hand only, making it
chiral.
- An orchestra conductor's baton (symmetrical stick) is achiral as it has no distinguishing
asymmetry.
- Scissors (not ambidextrous) are chiral; a right-handed pair cannot be superimposed on a
left-handed pair.
3. Draw each of the following structures on a piece of paper. Identify any stereo
centers in each by indicating the carbon number corresponding to a stereo
center. If there are no stereo centers in a compound, state "none".
A. 2,3-dimethylpentane
B. 3-methylcyclohexene
C. 1-bromo-2,2-dichloropropane
d. 2,2 dichloropropane
E. 1,2 dichlorobutane
2 methylhexane:
Organic Chemistry Module 3 Exam
1. Characterize each of the following objects as being chiral or achiral
A. Drill bit
B. Screw
C. Screwdriver
, D. Boot
Carrot:
Answer
A. Chiral
B. Chiral
C. Achiral
D. Chiral
E. Achiral
Expert Rationale:
- A drill bit and a screw are classic examples of objects that display handedness (i.e., chirality) because
their helical threads can exist in two non-superimposable mirror image forms (right- or left-handed).
- A screwdriver (with a simple cylindrical shaft and symmetric handle) displays bilateral symmetry and
is achiral.
- A standard boot (not a symmetric galosh) fits only one foot, so it is chiral—left and right boots are
non-superimposable.
- A carrot, if symmetric and not twisted, is typically achiral, though some biological carrots may exhibit
subtle twists (rarely relevant in general chemistry context).
2. Characterize each of the following objects as being chiral or achiral:
a. Pencil
b. Wine Glass
c. Baseball Glove
d. Orchestra Conductors' Baton
Scissors:
Answer
a. achiral
, b. achiral
c. chiral
d. achiral
e. chiral
Expert Rationale:
- A pencil, lacking features like a grip or label, is a uniform cylinder and thus achiral—its
mirror image is superimposable.
- A wine glass (without decorations or asymmetry), due to its radial symmetry about the
stem, is achiral.
- A baseball glove is purposely designed to fit either the left or right hand only, making it
chiral.
- An orchestra conductor's baton (symmetrical stick) is achiral as it has no distinguishing
asymmetry.
- Scissors (not ambidextrous) are chiral; a right-handed pair cannot be superimposed on a
left-handed pair.
3. Draw each of the following structures on a piece of paper. Identify any stereo
centers in each by indicating the carbon number corresponding to a stereo
center. If there are no stereo centers in a compound, state "none".
A. 2,3-dimethylpentane
B. 3-methylcyclohexene
C. 1-bromo-2,2-dichloropropane
d. 2,2 dichloropropane
E. 1,2 dichlorobutane
2 methylhexane:
