Organic II Quizzes + Worksheet

Question 1

The mass spectrum of alcohols often fails, to exhibit detectable M+ peaks but instead show relatively large ________ peaks.

Answer 1

M-18

Question 2

An odd molecular ion peak usually indicates what?

Answer 2

The presence of an odd number of nitrogen atoms in the molecule.

Question 3

Which of the following fragment peaks would not be present in the mass spectrum of n-hexane?
29
43
57
71
87

Answer 3

87

Question 4

What type of feature will be observed in the EI mass spectrum of chlorobenzene?

Answer 4

A signal at 112 and a signal at 114 in a ratio of 3:1

Question 5

The presence of iodine have a peak of m/z at ___ on the mass spectrum.

Answer 5

127

Question 6

For DEPT-135 what appears normally?

Answer 6

CH3 (methyl) and CH (methine) groups

Question 7

How many different kinds of carbons in 2-methylpentane?

Answer 7

5

Question 8

Anions for allylic species ________ (add or subtract) an electron.

Answer 8

add

Question 9

Bonding for MOs means what?

Answer 9

All orbitals are bonded (+ w/ + and - w/ -)

Question 10

Antibonding means what?

Answer 10

Max nodes or no bonded orbitals.

Question 11

H2SO4 with 2 alcohols create what?

Answer 11

An ether (R-O-R’)

Question 12

What does MCPBA do to a double bond?

Answer 12

Create an epoxide (triangle w/ O)

Question 13

Which has a lower b.p? Ether or alcohols?

Answer 13

Ether.

Question 14

Ether reacting with HI (excess) and heat produces what?

Answer 14

A cleavage of 2 iodine molecules.

Question 15

What does 1. Hg(OAc)2, CH3CH2OH, 2. NaBH4 do to a cyclic compound with a double bond?

Answer 15

Removes the double bond and add a OCH2CH3 substituent.

Question 16

What is the best path for the Williamson Ether Synthesis?

Answer 16

Primary alkyl halide and NaO-R compound.

Question 17

Is CH3OH an acid or base?
Attacks more or less substituted carbon for an epoxide?

Answer 17

Acid; more substituted
(OCH3 attacks less substituted)

Question 18

Is NaOCH3 a strong base or acid?

Answer 18

Strong base… attacks less substituted carbon

Question 19

The mass spectrum of which molecule has M+ & M+2 peaks of approximately equal intensity?

Answer 19

Bromine

Question 20

The presence of which element is indicated by a peak at m/z 127 and a characteristic 127-unit gap in the mass spectrum?

Answer 20

Iodine

Question 21

What usually indicates the presence of an odd number of nitrogen atoms in the molecule?

Answer 21

An odd molecular ion peak.

Question 22

The mass spectrum of which compound has an M+2 peak that has intensity that is about 25% of its M+ peak?

Answer 22

Chlorine

Question 23

The mass spectrum of which compound has an M+2 peak that has intensity that is about 4% of its M+ peak?

Answer 23

Sulfur

Question 24

What are the 2 modes of cleavage for alcohols?

Answer 24

At the alpha carbon and the allylic carbon.

Question 25

A reaction under kinetic (or rate) control will yield predominantly…

Answer 25

the product whose formation requires the smallest free energy of activation.

Question 26

Kinetic control gets a ___ product while thermodynamic control get a ___ product.

Answer 26

1,2- ; 1,4-

Question 27

Which forms faster, kinetic or thermodynamic control?

Answer 27

Kinetic

Question 28

What temperature is the thermodynamic and kinetic control at?

Answer 28

Thermodynamic: 40
Kinetic: -80

Question 29

Which control is irreversible? Thermodynamic or kinetic?

Answer 29

Kinetic

Question 30

Does the double bond move for thermodynamic control reactions?

Answer 30

Yes.

Question 31

How many electrons are present in the nonbonding π molecular orbital of the allyl anion?

Answer 31

2

Question 32

In an allyl cation, how many pi electrons are there?

Answer 32

2

Question 33

A thermodynamically-controlled reaction will yield predominantly…

Answer 33

the more/most stable product.

Question 34

Grignard reagents add to the ____ substituted carbon for epoxides.

Answer 34

less

Question 35

Give the formula for a Grignard reagent.

Answer 35

CH3MgBr

Question 36

Do ethers have much lower water solubilities than alcohols?

Answer 36

No.

Question 37

What reagents is suggested for adding an methoxy group to an epoxide?

Answer 37

NaOCH3 and CH3OH
or
CH3MgBr, H3O+

Question 38

What reagents is suggested for adding an methoxy group to a double bond?

Answer 38

1. Hg(OAc)2, CH3OH
2. NaBH4

Question 39

What does CH3CO3H do to a double bond?

Answer 39

Change double bond to an epoxide.

Question 40

MCBPA and CH2Cl2 reagent with a cyclohexene produces what?

Answer 40

An epoxide on the cyclic compound.