True and False: Practice Exam

Question 1

All reactions that have competing reaction pathways and transition states will always give the thermodynamically more stable product

Answer 1

False

Question 2

Cyclopropanone is an aromatic compound

Answer 2

False

Question 3

Claisen condensation of methyl acetate in the presence of sodium methoxide, followed by neutralization with acid, gives methyl acetoacetate CH3COCH 2CO 2CH 3

Answer 3

True

Question 4

Electrophilic aromatic substitution at high temperatures (> 50° C) is a concerted process, at lower temperatures (< 0° C) it’s a multi-step reaction with intermediates

Answer 4

False

Question 5

Hydrogen bonding helps contribute to water’s high boiling point of 100° C

Answer 5

True

Question 6

Hydrolysis of amides and esters can be catalyzed by acid or by base

Answer 6

True

Question 7

THF is a good solvent for organometallic reagents because it’s aprotic and its lone pair of electrons can coordinate to the metal in the organometallic bond

Answer 7

True

Question 8

The fastest step in a multistep reaction is called the rate-determining step

Answer 8

False

Question 9

1,3-cyclobutadiene is aromatic

Answer 9

False

Question 10

Pyridine is more basic than pyrrole

Answer 10

True

Question 11

The kinetic product of reaction of 1,3-butadiene with HBr is 1-bromo-2-trans-butene

Answer 11

False

Question 12

Acid-catalyzed hydrolysis of nitriles proceeds via initial formation of a primary amide, followed by further hydrolysis to a carboxylic acid

Answer 12

True

Question 13

The driving force for decarboxylation of beta-keto acids is the loss of CO2 gas and formation of an eno

Answer 13

True

Question 14

Phenol does not have a keto tautomer

Answer 14

False

Question 15

Rotation about the C-N sigma bond in an amide is faster than rotation about the C-Cl sigma bond in an acid chloride, since Cl is such a big atom

Answer 15

False

Question 16

Carboxylate anions cannot be alkylated with alkyl bromides

Answer 16

False

Question 17

Sodium borohydride will reduce the C=O bond in ketones, esters and amides

Answer 17

False

Question 18

Aldol condensation reactions are reversible

Answer 18

True

Question 19

Usually, there are 2 different ways to prepare an internal alkene via the Wittig reaction

Answer 19

True

Question 20

Reduction of 2-methylcyclobutanone with LiAlH 4 gives a pair of diastereomers

Answer 20

True

Question 21

Oxidation of an aldehyde group never occurs in water, because the carbonyl group is protected as its 1,1-geminal dio

Answer 21

False

Question 22

Epoxides are reactive due to ring strain and torsional strain

Answer 22

True

Question 23

Just like ketones, ester carbonyls can be easily “protected” with 1,2-diols

Answer 23

False

Question 24

Conjugation in allyl radical intermediate makes it easier to break C-H σ Bond

Answer 24

True

Question 25

Hammond’s postulate states that factors that influence the energy of an intermediate will also influence the structure and relative energy of the transition state that leads to that intermediate

Answer 25

True

Question 26

Diels-alder 4+2 cycloaddition is a concerted reaction

Answer 26

True

Question 27

Reactions under kinetic control depend on relative energies of transition states

Answer 27

True

Question 28

Reaction under thermodynamic control depends on the relative stability of products

Answer 28

True

Question 29

Good dienes are typically electron-rich

Answer 29

True

Question 30

Good dienophiles are typically electron-deficient

Answer 30

True