Exam 4

Question 1

nucleophile traits

Answer 1

-need lone pair or pi bond
-anions are good nucleophiles
-more electropositive= better nucleophiles
-larger atoms are more nucleophilic
*neutral Ns are moderate nucs
*neutral Os are poor nucs
*neutral Xs are not nucs

Question 2

electrophile

Answer 2

-alkyl group attached to a leaving group

Question 3

calculating oxidation reduction for carbon

Answer 3

• -1 for each bond to H or electropositive
• +1 for each bond to O or electronegative
• +0 for each bond to carbon

Question 4

OIL RIG

Answer 4

-oxidation is losing e-
-reduction is gaining e-

Question 5

oxidizing agents

Answer 5

-lots of O atoms
-often metal + O atoms, or lots of electronegative
ex. O2, O3, NaOCl, KMnO4, Cl2, Br2, OsO4

Question 6

reducing agents

Answer 6

-lots of H atoms
-often metal + H atoms, or lots of electropositive
ex. H2, NaBH4, LiAlH4, BH3, and metals

Question 7

LG traits (need 2 or more)

Answer 7

-atom receiving lone pair is big
-atom receiving lone pair is electronegative
-atom receiving lone pair has a positive charge
-atom receiving lone pair is in a strained ring
-the group can delocalize the negative charge by resonance

Question 8

SN2 rxn

Answer 8

-better nuc- faster rxn
-better LG- faster rxn
-Rgroup- ch3>1>2»3
-solvent- PA > PP

Question 9

SN1 rxn

Answer 9

-nuc has no effect
-better LG- faster rxn
-Rgroup- 3>2>1>CH3
-solvent- PP > PA

Question 10

E2 rxn

Answer 10

-stronger base- faster rxn
-better LG- faster rxn
-Rgroup- not methyl
-solvent- PA>PP

Question 11

E1 rxn

Answer 11

-stronger base- no effect
-better LG- faster rxn
-Rgroup- 3>2>1>CH3
-solvent- PP>PA

Question 12

polar protic solvents

Answer 12

ex. HOH, CH3OH, ROH, CH3COOH, NH3

Question 13

polar aprotic solvents

Answer 13

-abbreviated name usually
-ex. DMSO, acetone, DMF, THF, HMPA

Question 14

good nuc, strong base

Answer 14

-negative charge on small element
ex. -OH, CH3O-, NH2-

Question 15

good nuc, weak base

Answer 15

ex. Br-, Cl-, CH3S-, CH3CH2Se-, I-