Orgo Exam 3

Front 1

SN2 reactions always occur with what type of configuration?

Back 1

Inversion. Substrate is attacked by the nucleophile from the back side

Front 2

What is the free energy of activation or Delta G Prime?

Back 2

The difference in energy between the reactants and the transition state

Front 3

This is the difference in energy between reactants and the products.

Back 3

The free energy change for the reaction or Delta G

Front 4

What is the transition state on the reaction graph?

Back 4

The top of the energy curve

Front 5

What type of nucleophile results in a neutral product?

Back 5

Negatively charged nucleophile such as hydroxide

Front 6

Is a nucleophile an acid or a base and what type of charge does it have to have?

Back 6

It's always a Lewis base which is an electron-pair donor and it can be negatively charged or neutral

Front 7

Which group is always a species that takes a pair of electrons with it when it departs?

Back 7

The leaving group which is usually an electronegative atom such as the halide family

Front 8

As you go down the periodic table how does that affect bond strength and bond length?

Back 8

Bond length increases and the carbon halogen bond strength decreases

Front 9

What is a Bronsted-Lowry base?

Back 9

Accepts a proton

Front 10

How can you compare the relative stabilities of carbo cations?

Back 10

Look at the number of alkyl groups attached to the positively charged carbon. Tertiary carbo cations are the most stable and methyl carbo cations are the least stable.

Front 11

What are the best types of leaving groups?

Back 11

Ones that become weak bases

Front 12

SN2 reactions are favored by which solvents?

Back 12

Polar aprotic solvents

Front 13

SN1 reactions are favored by which solvents?

Back 13

Polar PROTIC solvents

ie EtOH, MeOH, H2O

Front 14

What is the trend in nucleophilicity among halide anions in a PROTIC solvent?

Back 14

I>Br>Cl>F

Front 15

What is the trend in nucleophilicity among halide anions in an APROTIC solvent?

Back 15

F>Cl>Br>I

Front 16

A substrate with a relatively unhindered leaving group favors_____

Back 16

An SN2 reaction

Front 17

Tertiary halides do not react by an _____mechanism

Back 17

SN2

Front 18

A substrate that can form a stable carbocation favors a _____ reaction. The substrate would have a _____ in the tertiary position

Back 18

SN1; leaving group

Front 19

Which mechanism is important in solvolysis reactions?

Back 19

SN1

Front 20

Which type of solvents hinder the nucleophile in sn2 reactions? Why?

Back 20

PROTIC because hydrogen bonding encumbers it's reactivity in substitution reactions

Front 21

How do smaller more concentrated anions affect solvation?

Back 21

They are more strongly solvated and are not as effective of a nucleophile. Iodide is strongest compared to F

Front 22

Rate constant k , is dependent on which 3 factors?

Back 22

Catalyst, temperature, energy of activation or Ea

Front 23

The RATE of a reaction is dependent on what?

Back 23

Reactants, k, temp, Ea

Front 24

True or false. Activation energy is dependent on temperature?

Back 24

False

Front 25

SN1 reactions have _____ kinetics and are _______, which means the rate depends on concentration of ______.

Back 25

First order, unimolecular, the substrate only

Front 26

The rate of a SN2 reaction depends on what?

Back 26

Concentration AND identity of attacking nucleophile

Front 27

SN1 reaction rates are increased in what type of solvent?

Back 27

Polar PROTIC or ionizing solvent

Front 28

In which type of solvent does nucleophilicity correlate with basicity?

Back 28

Polar aprotic

Front 29

Secondary , allylic, and and benzylic substrates can proceed though which mechanism?

Back 29

SN1 or sn2

Vinyl and aryl substrates can NOT undergo either

Front 30

Rank the stabilities of carbocations

Back 30

Benzylic/allylic, 3°,2°,1°, Me