Chem 3

Question 1

Write the differences between the inductive effect and the field effect.

Answer 1

Inductive effect is polarization through sigma bond.
Field effect is polarization through space.

Question 2

+I groups

Answer 2

NH4+ (Ammonium group)
H3O+ (Hydronium group)
C2H3+ (Vinyl group)
CH3+ (Methyl group)
C3H5+ (Allyl group)

Question 3

-I group

Answer 3

NH2- (Amino group)
OH- (Hydroxyl group)
CHO- (Carbonyl group)
NO2- (Nitro group)
HSO3- (Sulfonic group)

Question 4

Arrange the relative strength of the following factors on a molecules acidity: Resonance, Atomic radius, Electronegativity, and Inductive effect.

Answer 4

Inductive effect, Electronegativity,
Atomic radius,
Resonance

Question 5

The formal charge on nitrogen and oxygen in NO+ is:

Answer 5

0 and +1

Question 6

Non-superimposable stereoisomers, which are mirror images of each other, are known as _________.

Answer 6

Enatiomers

Question 7

Non-superimposable stereoisomers that are not mirror images of each other, are known as ____________

Answer 7

Diastereomers

Question 8

Diastereoisomers are possible only when the molecule contains more than ______ chiral center.

Answer 8

One

Question 9

E / Z alkene isomers are known as ______________________

Answer 9

Geometric isomers

Question 10

The structure of the molecule, (Z)-3-ethyl-2-pentene-4-yne, is ________

Answer 10

Trans

Question 11

Molecules (or objects) that possess a mirror plane of symmetry, are superimposable on their mirror image, are termed as ___________

Answer 11

Achiral

Question 12

A molecule containing carbon with four different groups results in a _______ molecule, and the carbon is referred to as a __________ center

Answer 12

chiral ; stereogenic

Question 13

Molecules enriched in an enantiomer will rotate plane-polarized light and are said to be __________ active

Answer 13

Optically

Question 14

The optical rotation depends upon the substance, concentration, path length through the sample, and _______________ of light

Answer 14

Wavelength

Question 15

A polarimeter measures the rotation of _____________ light that has passed through a solution.

Answer 15

Plane-polarized

Question 16

Plane polarized light is the light that oscillates in only one plane;when it passes through, the solution of an achiral compound remains in that plane, and the optical rotation is _____________

Answer 16

Optically inactive

Question 17

Solutions of chiral compounds rotate plane-polarized light, and the molecules are said to be _____________ active.

Answer 17

Optically

Question 18

Enantiomers will rotate plane-polarized light of the same magnitude (a) but in __________ directions.

Answer 18

Opposite

Question 19

The specific rotation is a ____________ of a chiral molecule

Answer 19

Physical constant

Question 20

If ______________ exists between two chiral conformers, the molecule is not chiral.

Answer 20

Equilibrium

Question 21

The maximum number of possible stereoisomers of D-(+)-glucose is?

Answer 21

16

Question 22

Maximum number of possible stereoisomers and stereocenters of cholesterol is?

Answer 22

256

Question 23

What is optical resolution?

Answer 23

The separation of racemic compounds into enantomers.

Question 24

What is racemate?

Answer 24

When enantomers in a compound are equal.

Question 25

According to the R-S convention, which priority is correct for the following sets of functional groups/atoms?

Answer 25

Cl > NH2 > CH3 > H

Question 26

Which of the following groups has the highest priority for assigning R-S absolute configuration?

Answer 26

(CH3) 3C-

Question 27

Trivalent nitrogen is ______, does not exhibit chirality because of rapid_______.

Answer 27

tetrahedral ; flipping

Question 28

Trivalent phosphorus is ______, exhibits chirality because of slow_______.

Answer 28

tetrahedral ; flipping

Question 29

A molecule that is ________ but that can become chiral by a ______ alteration is a prochiral molecule.

Answer 29

achiral ; single

Question 30

Re and Si are used to describe the _______ of the _______ sp2 reactant.

Answer 30

faces ; prochiral

Question 31

SN-1 reactions show first-order kinetics because?

Answer 31

The rate-determining step involves only one molecule

Question 32

Treatment of (S)-2-bromobutane with sodium hydroxide results in the production of a compound with an (R) configuration. The reaction has most likely taken place through?

Answer 32

SN-2

Question 33

Which statement is true for SN2 reactions?

Answer 33

Displacement occurs with inversion of configuration

Question 34

Which of the following is a polar aprotic solvent?

Answer 34

CH3CN (CH3) 2S=O

Question 35

The SN2 mechanism for nucleophilic substitution reactions

Answer 35

Involves one step and occurs with inversion of configuration

Question 36

When 1-bromobutane is reacted with the bulky base, potassium t-butoxide, in t-butyl alcohol, the major elimination product is:

Answer 36

1-butene

Question 37

Antiperiplanar geometry is usually preferred for _________ reaction.

Answer 37

E2

Question 38

For primary alkyl halides ________ is favored with most nucleophiles, but _________ is favored with bulky bases like tbutoxide.

Answer 38

SN2 ; E2

Question 39

Inductive effect is a ___________ effect, whereas the electrometric effect is a ___________ effect

Answer 39

Permanent, temporary

Question 40

The ___________ of chemical bonds never releases energy to the external environment. Energy is only released when chemical bonds are _________.

Answer 40

Breaking, formed