CHEM 232 Exam 2 Questions with
Verified Solutions
A _________ is a reactive intermediate with a single unpaired electron, formed by
homolysis of a covalent bond - ANSWER-radical
A ____________ contains an atom that does not have an octet of electrons, making it
reactive and unstable - ANSWER-radical
Radical processes involve _________ electrons, so half headed arrows are used to
show the movement of electrons. ________________ arrow is used for each electron -
ANSWER-single
one half-headed
____________ are classified as primary(1), secondary (2), or tertiary (3) by the number
of R groups bonded to the carbon with the unpaired electrons. - ANSWER-carbon
radicals
A _______________ is sp2 hybridized and trigonal planar, like sp2 hybridized
carbocations. The _________________ contains the unpaired electron and extends
above and below the trigonal planar carbon. - ANSWER-carbon radical
unhybridized p orbital
Cleavage of the weaker bond forms the _____________ radical (a specific example of a
general trend) - ANSWER-more stable
The stability of a radical _________ as the number of alkyl groups bonded to the radical
carbon increases - ANSWER-increases
Radical reactions are different from other organic reactions in that radical processes
involve the movement of ____________ electrons - ANSWER-single
Alkyl groups are more ________________ than the hydrogen atoms, so they can more
easily donate electron density to the electron deficient carbon radical, thus
____________ stability - ANSWER-polarizable
increasing
Radicals are formed from covalent bonds by adding energy in the form of ________ or
___________ - ANSWER-heat (Δ)
light (hv)
, Allylic halides have X bonded to the carbon atom ___________ to a carbon-carbon
double bond, and benzylic halides - ANSWER-adjacent
An alkyl halide is named as an alkane with a halogen substituent—that is, as a
___________________ - ANSWER-halo alkane
Alkyl halides are weakly polar molecules. They exhibit
_______________________________ interactions because of their polar C X bond, but
because the rest of the molecule contains only C C and C H bonds they are incapable
of intermolecular hydrogen bonding. - ANSWER-dipole-dipole
The properties of alkyl halides dictate their _____________ - ANSWER-reactivity.
The electrostatic potential maps of four simple alkyl halides that the electronegative
halogen X creates a polar C X bond, making the carbon atom electron deficient. The
chemistry of alkyl halides is determined by
________________________________________ - ANSWER-this polar C X bond.
What kind of reactions do alkyl halides undergo? - ANSWER-The characteristic
reactions of alkyl halides are substitution and elimination.
In a substitution reaction of an alkyl halide, the halogen X is replaced by
___________________________ :Nu−. The C X σ bond is broken and the C Nu σ bond
is formed. - ANSWER-an electron-rich nucleophile
Alkyl halides undergo elimination reactions with _______________ - ANSWER-
Brønsted-Lowry bases.
In an _________________ of an alkyl halide, the elements of HX are removed by a
Brønsted-Lowry base :B. - ANSWER-elimination reaction
_____________ components are necessary in any substitution reaction. - ANSWER-
Three
Because these substitution reactions involve electron-rich nucleophiles, they are called
________________________________________ - ANSWER-nucleophilic substitution
reactions
Nucleophilic substitutions are______________________ - ANSWER-Lewis acid-base
reactions.
The nucleophile donates its electron pair, the alkyl halide (Lewis acid) accepts it, and
the C X bond is heterolytically cleaved. Curved arrow notation can be used to show the
movement of electron pairs
Verified Solutions
A _________ is a reactive intermediate with a single unpaired electron, formed by
homolysis of a covalent bond - ANSWER-radical
A ____________ contains an atom that does not have an octet of electrons, making it
reactive and unstable - ANSWER-radical
Radical processes involve _________ electrons, so half headed arrows are used to
show the movement of electrons. ________________ arrow is used for each electron -
ANSWER-single
one half-headed
____________ are classified as primary(1), secondary (2), or tertiary (3) by the number
of R groups bonded to the carbon with the unpaired electrons. - ANSWER-carbon
radicals
A _______________ is sp2 hybridized and trigonal planar, like sp2 hybridized
carbocations. The _________________ contains the unpaired electron and extends
above and below the trigonal planar carbon. - ANSWER-carbon radical
unhybridized p orbital
Cleavage of the weaker bond forms the _____________ radical (a specific example of a
general trend) - ANSWER-more stable
The stability of a radical _________ as the number of alkyl groups bonded to the radical
carbon increases - ANSWER-increases
Radical reactions are different from other organic reactions in that radical processes
involve the movement of ____________ electrons - ANSWER-single
Alkyl groups are more ________________ than the hydrogen atoms, so they can more
easily donate electron density to the electron deficient carbon radical, thus
____________ stability - ANSWER-polarizable
increasing
Radicals are formed from covalent bonds by adding energy in the form of ________ or
___________ - ANSWER-heat (Δ)
light (hv)
, Allylic halides have X bonded to the carbon atom ___________ to a carbon-carbon
double bond, and benzylic halides - ANSWER-adjacent
An alkyl halide is named as an alkane with a halogen substituent—that is, as a
___________________ - ANSWER-halo alkane
Alkyl halides are weakly polar molecules. They exhibit
_______________________________ interactions because of their polar C X bond, but
because the rest of the molecule contains only C C and C H bonds they are incapable
of intermolecular hydrogen bonding. - ANSWER-dipole-dipole
The properties of alkyl halides dictate their _____________ - ANSWER-reactivity.
The electrostatic potential maps of four simple alkyl halides that the electronegative
halogen X creates a polar C X bond, making the carbon atom electron deficient. The
chemistry of alkyl halides is determined by
________________________________________ - ANSWER-this polar C X bond.
What kind of reactions do alkyl halides undergo? - ANSWER-The characteristic
reactions of alkyl halides are substitution and elimination.
In a substitution reaction of an alkyl halide, the halogen X is replaced by
___________________________ :Nu−. The C X σ bond is broken and the C Nu σ bond
is formed. - ANSWER-an electron-rich nucleophile
Alkyl halides undergo elimination reactions with _______________ - ANSWER-
Brønsted-Lowry bases.
In an _________________ of an alkyl halide, the elements of HX are removed by a
Brønsted-Lowry base :B. - ANSWER-elimination reaction
_____________ components are necessary in any substitution reaction. - ANSWER-
Three
Because these substitution reactions involve electron-rich nucleophiles, they are called
________________________________________ - ANSWER-nucleophilic substitution
reactions
Nucleophilic substitutions are______________________ - ANSWER-Lewis acid-base
reactions.
The nucleophile donates its electron pair, the alkyl halide (Lewis acid) accepts it, and
the C X bond is heterolytically cleaved. Curved arrow notation can be used to show the
movement of electron pairs
