Chem 3 Flashcards
Write the differences between the inductive effect and the field effect.
Inductive effect is polarization through sigma bond.
Field effect is polarization through space.
+I groups
NH4+ (Ammonium group)
H3O+ (Hydronium group)
C2H3+ (Vinyl group)
CH3+ (Methyl group)
C3H5+ (Allyl group)
-I group
NH2- (Amino group)
OH- (Hydroxyl group)
CHO- (Carbonyl group)
NO2- (Nitro group)
HSO3- (Sulfonic group)
Arrange the relative strength of the following factors on a molecules acidity: Resonance, Atomic radius, Electronegativity, and Inductive effect.
Inductive effect, Electronegativity,
Atomic radius,
Resonance
The formal charge on nitrogen and oxygen in NO+ is:
0 and +1
Non-superimposable stereoisomers, which are mirror images of each other, are known as _________.
Enatiomers
Non-superimposable stereoisomers that are not mirror images of each other, are known as ____________
Diastereomers
Diastereoisomers are possible only when the molecule contains more than ______ chiral center.
One
E / Z alkene isomers are known as ______________________
Geometric isomers
The structure of the molecule, (Z)-3-ethyl-2-pentene-4-yne, is ________
Trans
Molecules (or objects) that possess a mirror plane of symmetry, are superimposable on their mirror image, are termed as ___________
Achiral
A molecule containing carbon with four different groups results in a _______ molecule, and the carbon is referred to as a __________ center
chiral ; stereogenic
Molecules enriched in an enantiomer will rotate plane-polarized light and are said to be __________ active
Optically
The optical rotation depends upon the substance, concentration, path length through the sample, and _______________ of light
Wavelength
A polarimeter measures the rotation of _____________ light that has passed through a solution.
Plane-polarized
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 _____________
Optically inactive
Solutions of chiral compounds rotate plane-polarized light, and the molecules are said to be _____________ active.
Optically
Enantiomers will rotate plane-polarized light of the same magnitude (a) but in __________ directions.
Opposite
The specific rotation is a ____________ of a chiral molecule
Physical constant
If ______________ exists between two chiral conformers, the molecule is not chiral.
Equilibrium
The maximum number of possible stereoisomers of D-(+)-glucose is?
16
Maximum number of possible stereoisomers and stereocenters of cholesterol is?
256
What is optical resolution?
The separation of racemic compounds into enantomers.
What is racemate?
When enantomers in a compound are equal.
According to the R-S convention, which priority is correct for the following sets of functional groups/atoms?
Cl > NH2 > CH3 > H
Which of the following groups has the highest priority for assigning R-S absolute configuration?
(CH3) 3C-
Trivalent nitrogen is ______, does not exhibit chirality because of rapid_______.
tetrahedral ; flipping
Trivalent phosphorus is ______, exhibits chirality because of slow_______.
tetrahedral ; flipping
A molecule that is ________ but that can become chiral by a ______ alteration is a prochiral molecule.
achiral ; single
Re and Si are used to describe the _______ of the _______ sp2 reactant.
faces ; prochiral
SN-1 reactions show first-order kinetics because?
The rate-determining step involves only one molecule
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?
SN-2
Which statement is true for SN2 reactions?
Displacement occurs with inversion of configuration
Which of the following is a polar aprotic solvent?
CH3CN
(CH3) 2S=O
The SN2 mechanism for nucleophilic substitution reactions
Involves one step and occurs with inversion of configuration
When 1-bromobutane is reacted with the bulky base, potassium t-butoxide, in t-butyl alcohol, the major elimination product is:
1-butene
Antiperiplanar geometry is usually preferred for _________ reaction.
E2
For primary alkyl halides ________ is favored with most nucleophiles, but _________ is favored with bulky bases like tbutoxide.
SN2 ; E2
Inductive effect is a ___________ effect, whereas the electrometric effect is a ___________ effect
Permanent, temporary
The ___________ of chemical bonds never releases energy to the external environment. Energy is only released when chemical bonds are _________.
Breaking, formed
