Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
CHEM 245- Unit 2
| Question | Answer |
|---|---|
| all reactions of benzene are | substitution reactions (to keep aromatic ring structure) |
| electron donating groups bond at | 50% ortho, 50% meta |
| electron withdrawing groups bond at | 81% meta |
| rules for determining aromaticity | cyclic, p-orbital, every p-orbital must overlap, pi cloud must contain an odd pair of electrons (4n+2 total electrons) |
| 2 most important aromaticity rules | cyclic, 4n+2 total electrons |
| when do molecules become non-superimposable mirror images? | >2 substitutions |
| clockwise stereochemistry | R |
| counterclockwise stereochemistry | S |
| chiral | not identical to its mirror images |
| achiral | has an internal plane of symmetry |
| clockwise (optically) | dextrorotatory (+) |
| counterclockwise (optically) | levorotatory (-) |
| diastereomer | non-superimposable, non-mirror images |
| do diastereomers have the same physical properties? | no |
| do enantiomers have the same physical properties? | yes |
| # of stereoisomers | 2^(chirality centers) |
| meso compounds | mirror image, rotate 180 is the same as original *have chirality centers, but achiral because of the mirror plane |
| organohalide elimination trend | more stable with tertiary compounds |
| rate law SN2 reactions | k[Nu][R3C-X] |
| SN2 reactions | occur in a single step without an intermediate |
| SN2 rates | fastest with fewest substitutions; less electronegative anions=better |
| SN2 leaving groups | gases are best; stable anions of strong acids 2nd |
| what does SN2 stand for? | substitution nucleophilic bimolecular |
| what does SN1 stand for? | substitution nucleophilic unimolecular |
| rate law SN1 reactions | k[starting material] |
| SN1 only occurs under ____ conditions | neutral or acidic |
| RDS SN1 | carbocation formation |
| are SN1 stereoselective? | nope |
| SN1 leaving groups | similar to SN2; less electronegative anions; H2O neutral, OH acidic |
| rate law E2 | k[reactant][base] |
| E2 requires | an antiperiplanar relationship between a H and LG |
| acyclic E2 | more highly substituted alkene is formed (same as cyclic if available) |
| E1 rate law | k[starting material] |
| if substrates that work well with both E1 and SN1 are combined... | a mixture of SN1 and E1 products will form |
| primary alkyl halides will use what mechanism(s)? | SN2 if good nucleophile present E2 if no good nucleophile (base like (CH3)3O) |
| secondary alkyl halides will use what mechanism(s)? | SN2 if good nucleophile present- weakly basic E2 if no good nucleophile (base like (CH3)3O) |
| tertiary alkyl halides will use what mechanism(s)? | SN1 or E1 under acidic or neutral E2 if basic |
| SN2 needs an available ___ to occur | sigma * |
| SN1 won't occur if _____ is happening on the molecule | ring strain |
| E2 likes what base? | t-butoxide |
| E1 makes a | double bond |
Created by:
melaniebeale
Popular Chemistry sets