Organic Chemistry -- Chapter 5 Exam
Questions With Correct Solutions 100%
What are *stereoisomers*? - ANSWER-Compounds that differ from each other only in
the three-dimensional, spatial arrangement of their atoms, but not in the connectivity of
their atoms
Isomers - ANSWER-"made of the same parts"
Compounds that are constructed from the same atoms (same molecular formula) but
that differ from each other
What are the two types of isomers? - ANSWER-1. Constitutional isomers
2. Stereoisomers
What are constitutional isomers? - ANSWER-Same molecular formula but different
constitution (order of connectivity of atoms)
What are stereoisomers? - ANSWER-Same molecular formula and constitution but
different spatial arrangement of atoms
Example of constitutional isomers - ANSWER-Notice that constitution affects BP
Example of stereoisomers on a ring (cis vs. trans) - ANSWER-
Example of stereoisomers on a double bond - ANSWER-
Do double bonds (pi-bonds) experience free rotation like single bonds (sigma bonds)? -
ANSWER-No. This is because pi-bonds are formed by the overlap of two p orbitals.
Rotation about the C--C double bond would destroy the overlap between the p orbitals.
, What does trans mean? - ANSWER-Groups on the opposite side
What does superimposable mean? - ANSWER-That the mirror image of an object is
identical to the actual object
Nonsuperimposable - ANSWER-The mirror image is different than the actual object
Objects that are not superimposable on their mirror images are said to be... - ANSWER-
chiral objects
All 3-D objects can be classified as either chiral or ____ - ANSWER-achiral
Chiral molecules - ANSWER-They are nonsuperimposable on their mirror images
Achiral molecules - ANSWER-They are superimposable on their mirror images
Most common source of molecular chirality? - ANSWER-Presence of a carbon atom
bearing four *different* groups
Structure of 2-Butanol - ANSWER-These two compounds are nonsuperimposable
mirror images, and represent two different compounds. They differ from each other only
in the spatial arrangement of their atoms, therefore, they are said to be stereoisomers
Examples of stereoisomers - ANSWER-
Examples of chirality centers - ANSWER-
Chirality center - ANSWER-A tetrahedral carbon bearing four different groups
How to find chirality centers - ANSWER-1. Eliminate all double and triple bonds
2. Eliminate all CH2 and CH3 groups
Questions With Correct Solutions 100%
What are *stereoisomers*? - ANSWER-Compounds that differ from each other only in
the three-dimensional, spatial arrangement of their atoms, but not in the connectivity of
their atoms
Isomers - ANSWER-"made of the same parts"
Compounds that are constructed from the same atoms (same molecular formula) but
that differ from each other
What are the two types of isomers? - ANSWER-1. Constitutional isomers
2. Stereoisomers
What are constitutional isomers? - ANSWER-Same molecular formula but different
constitution (order of connectivity of atoms)
What are stereoisomers? - ANSWER-Same molecular formula and constitution but
different spatial arrangement of atoms
Example of constitutional isomers - ANSWER-Notice that constitution affects BP
Example of stereoisomers on a ring (cis vs. trans) - ANSWER-
Example of stereoisomers on a double bond - ANSWER-
Do double bonds (pi-bonds) experience free rotation like single bonds (sigma bonds)? -
ANSWER-No. This is because pi-bonds are formed by the overlap of two p orbitals.
Rotation about the C--C double bond would destroy the overlap between the p orbitals.
, What does trans mean? - ANSWER-Groups on the opposite side
What does superimposable mean? - ANSWER-That the mirror image of an object is
identical to the actual object
Nonsuperimposable - ANSWER-The mirror image is different than the actual object
Objects that are not superimposable on their mirror images are said to be... - ANSWER-
chiral objects
All 3-D objects can be classified as either chiral or ____ - ANSWER-achiral
Chiral molecules - ANSWER-They are nonsuperimposable on their mirror images
Achiral molecules - ANSWER-They are superimposable on their mirror images
Most common source of molecular chirality? - ANSWER-Presence of a carbon atom
bearing four *different* groups
Structure of 2-Butanol - ANSWER-These two compounds are nonsuperimposable
mirror images, and represent two different compounds. They differ from each other only
in the spatial arrangement of their atoms, therefore, they are said to be stereoisomers
Examples of stereoisomers - ANSWER-
Examples of chirality centers - ANSWER-
Chirality center - ANSWER-A tetrahedral carbon bearing four different groups
How to find chirality centers - ANSWER-1. Eliminate all double and triple bonds
2. Eliminate all CH2 and CH3 groups
