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1

(CH3)2CHCH2CHO has how many a-hydrogens?
A)1
B)2
C)3
D)4
E)6
2

Other than nucleophilic attacks at the carbonyl carbon, the most important reaction for aldehydes and ketones is?
A)electrophilic attacks at the carbonyl oxygen.
B)electrophilic attacks at the carbonyl carbon.
C)electrophilic attacks at the a-carbon.
D)nucleophilic additions at the a-carbon.
E)nucleophilic substitutions at the a-carbon.
3

Halogenation reactions for aldehydes and ketones is a free radical mechanism?
A)True.
B)False.
4

The rate of a halogenation reaction of an aldehyde depends on?
A)the concentration of the aldehyde.
B)the concentration of the halide.
C)the concentration of both the aldehyde and halide.
D)the concentration of neither species.
E)the pressure.
5

Tautomers are?
A)structural isomers.
B)conformational isomers.
C)configurational isomers.
D)geometric isomers.
E)stereo isomers.
6

With the exception of small aldehydes, the keto form predominates over the enol form, why?
A)the carbon-oxygen double bond is weaker than a carbon-carbon double bond.
B)the carbon-oxygen double bond is stronger than a carbon-carbon double bond.
C)the presence of electron donation in the enol form.
D)the absence of electron donation in the keto form.
E)changes in steric interactions.
7

The enol form is predominant for compounds which can?
A)stabilize the enol by resonance.
B)stabilize the enol by intramolecular hydrogen bonding.
C)stabilize the enol form by the presence of electron donation.
D)A and B.
E)A and C.
F)B and C.
8

In contrast to alkanes the a-hydrogen of aldehydes and ketones have a pKa of?
A)-10 to -5.
B)-5 to 0.
C)0 to 10.
D)10 to 15.
E)15 to 20.
F)35 to 45.
9

Base catalyzed halogenation of methyl ketones stops with the addition of a?
A)single halide atom.
B)two halide atoms.
C)three halide atoms.
D)four halide atoms.
E)the reaction does not occur.
10

If the a-carbon is a stereo center?
A)the chirality of the center is maintain
B)the chirality of the center inverts.
C)the product is a racemate.
11

Which statement about the Aldol reaction is false?
A)a base is required to initiate the reaction.
B)the aldehyde (or ketone) reacts via an enol intermediate.
C)the product is a g-hydroxy aldehyde or ketone.
D)the product can be heated to dehydrate it.
E)the reaction is an important means of generating new carbon-carbon bonds.
12

Mixed Aldol reactions require?
A)only one of the reactants to be able to form an enolate.
B)one of the reactants to be more reactive towards the nucleophile.
C)much stronger bases.
D)A and B.
E)A and C.
F)B and C.
13

a,b-unsaturated ketones can react via a direct addition (1,2-addition) or a conjugate addition (1,4-addition). Which statement about these reactions is false?
A)the thermodynamic product is the conjugate addition.
B)the kinetic product is a 1,4-addition.
C)weak bases favor the thermodynamic product.
D)the intermediates in both reactions are enolate ions.
E)strong nucleophiles favor the kinetic product.
14

Which statement about the Michael's addition is false?
A)the nucleophile is generally the enolate ion of a diketone.
B)the substrate is an a,b-unsaturated ketone.
C)the enolate is weakly basic.
D)the reaction is a conjugate addition.
E)the reaction is a 1,4-addition.
15

Which statement about the alkylation of aldehydes or ketones is false?
A)the nucleophile is the enolate ion.
B)the substrate is an alkyl halide.
C)the reaction occurs in an SN1 mechanism.
D)all of the a-hydrogens are reactive.
E)b-diketones are an excellent starting material.





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