DAT Organic Chemistry Review Practice
Test.
Which are more stable conformers - CORRECT ANSWER staggered
What are the rate laws of SN2 and E2 reactions - CORRECT ANSWER rate= k [RX][Nu:-]
rate depends on concentrations of alkyl halide and nucleophile
What are the rate laws of SN1 and E1 reactions - CORRECT ANSWER rate= k[RX]
rate only depends on the concentration of the alkyl halide
E2 elimination reactions must occur in bonds that are - CORRECT ANSWER coplanar or antiperiplanar
this type of reaction is stereospecific: one E or Z stereoisomer predominates
Most stable chair conformation - CORRECT ANSWER 1. convert to 2D structure following trans or cis
denotations
2. draw onto chair conformation
What mixtures can be separated by conventional physical methods - CORRECT ANSWER enantiomers
-identical chemical and physical properties except their ability to rotate plane polarized light by equal
amounts but in opposite directions
,Enantiomeric relationships with chair conformations - CORRECT ANSWER 1. draw the pairs into 2D
confirmations
down= dashed
up= shaded
What type of molecules exhibit optical activity - CORRECT ANSWER molecules with chiral centers
aldol condensation - CORRECT ANSWER The aldol reaction combines two carbonyl compounds to form a
new β-hydroxy carbonyl compound (aldol addition product). Further condensation (elimination of
water) results in an α,β-unsaturated carbonyl compound
β-hydroxy carbonyl - CORRECT ANSWER
α,β-unsaturated carbonyl - CORRECT ANSWER after H2O is removed
Acid attacks an epoxide - CORRECT ANSWER more substituted side
results in stereochemistry inversion
Cyclopentadiene - CORRECT ANSWER -conjugate base is aromatic
-planar conjugated system with 6 pi electrons
-produces stable free radical
-all atoms are spy hybridized
the more s character= - CORRECT ANSWER more acidic
, sp> sp2 > sp3
weakest base - CORRECT ANSWER electrons are least available
-resonance delocalization
Aromaticity rules - CORRECT ANSWER 1. cyclic or polycyclic
2. all the atoms in the ring must be spy or sp hybridized
3. the number of pi electrons in a ring must equal 4n + 2 = huckles rule
unsaturation formula - CORRECT ANSWER C- (H/2)- (X/2) + (N/2) + 1
SN1 reactions are most reactive towards - CORRECT ANSWER tertiary
Stability of alkenes - CORRECT ANSWER the greater the number of attached alkyl groups the more stable
the alkene will be
E>Z>but-1-ene
Tollens test - CORRECT ANSWER aldehydes
Iodoform test - CORRECT ANSWER ketones or aldehydes attached to a methyl group produce ionate
Br2/CCL4 - CORRECT ANSWER alkenes and alkynes react
red to clear solution
Test.
Which are more stable conformers - CORRECT ANSWER staggered
What are the rate laws of SN2 and E2 reactions - CORRECT ANSWER rate= k [RX][Nu:-]
rate depends on concentrations of alkyl halide and nucleophile
What are the rate laws of SN1 and E1 reactions - CORRECT ANSWER rate= k[RX]
rate only depends on the concentration of the alkyl halide
E2 elimination reactions must occur in bonds that are - CORRECT ANSWER coplanar or antiperiplanar
this type of reaction is stereospecific: one E or Z stereoisomer predominates
Most stable chair conformation - CORRECT ANSWER 1. convert to 2D structure following trans or cis
denotations
2. draw onto chair conformation
What mixtures can be separated by conventional physical methods - CORRECT ANSWER enantiomers
-identical chemical and physical properties except their ability to rotate plane polarized light by equal
amounts but in opposite directions
,Enantiomeric relationships with chair conformations - CORRECT ANSWER 1. draw the pairs into 2D
confirmations
down= dashed
up= shaded
What type of molecules exhibit optical activity - CORRECT ANSWER molecules with chiral centers
aldol condensation - CORRECT ANSWER The aldol reaction combines two carbonyl compounds to form a
new β-hydroxy carbonyl compound (aldol addition product). Further condensation (elimination of
water) results in an α,β-unsaturated carbonyl compound
β-hydroxy carbonyl - CORRECT ANSWER
α,β-unsaturated carbonyl - CORRECT ANSWER after H2O is removed
Acid attacks an epoxide - CORRECT ANSWER more substituted side
results in stereochemistry inversion
Cyclopentadiene - CORRECT ANSWER -conjugate base is aromatic
-planar conjugated system with 6 pi electrons
-produces stable free radical
-all atoms are spy hybridized
the more s character= - CORRECT ANSWER more acidic
, sp> sp2 > sp3
weakest base - CORRECT ANSWER electrons are least available
-resonance delocalization
Aromaticity rules - CORRECT ANSWER 1. cyclic or polycyclic
2. all the atoms in the ring must be spy or sp hybridized
3. the number of pi electrons in a ring must equal 4n + 2 = huckles rule
unsaturation formula - CORRECT ANSWER C- (H/2)- (X/2) + (N/2) + 1
SN1 reactions are most reactive towards - CORRECT ANSWER tertiary
Stability of alkenes - CORRECT ANSWER the greater the number of attached alkyl groups the more stable
the alkene will be
E>Z>but-1-ene
Tollens test - CORRECT ANSWER aldehydes
Iodoform test - CORRECT ANSWER ketones or aldehydes attached to a methyl group produce ionate
Br2/CCL4 - CORRECT ANSWER alkenes and alkynes react
red to clear solution
