Chapter 5

Question 1

Alcohol functional group

Answer 1

-OH
hydroxyl group

Question 2

Alcohol suffix

Answer 2

-ol

Question 3

Phenols

Answer 3

Aromatic alcohols = Hydroxyl groups attached to aromatic rings

Question 4

Ortho or o prefix

Answer 4

2 functional groups are on adjacent carbons in a ring

Question 5

Meta or m prefix

Answer 5

2 functional groups are separated by 1 Carbon on a ring

Question 6

Para or p prefix

Answer 6

2 functional groups are in opposite sides of a ring

Question 7

alkoxide ions

Answer 7

the conjugate base to an alcohol

an ion with an organic group bonded to a negatively charged oxygen atom

Question 8

the hydroxyl hydrogen is weakly ______ (acidic/basic)

Answer 8

acidic

Question 9

alcohols can dissociate into ___________

Answer 9

protons and alkoxide ions

Question 10

Key physical property of alcohol

Answer 10

High melting points due to hydrogen bonding of OH Groups

Question 11

hydroxyl hydrogens of phenols are ______ acidic than other alcohols

Answer 11

more

Question 12

are alcohols soluble in water? why?

Answer 12

yes if there is a relatively small hydrophobic alkyl group; the hydrophilic hydroxyl group can hydrogen bond with the water

no if there is a large hydrophobic alkyl group

Question 13

Electron withdrawing substituents ____ acidity

Answer 13

Increase

Question 14

Electron donating substituents ____ acidity

Answer 14

Decrease

Question 15

More alkyl groups on non aromatic alcohols = _____ acidic

Answer 15

Less acidic

Bc alkyl groups destabilize negative charge

Question 16

More substituted carbocations have _____ stability

Answer 16

Higher

Bc alkyl groups help stabilize positive charges

Question 17

Why are phenols more acidic than other alcohols

Answer 17

Possible Resonance between the ring and the lone pairs of the oxygen in the OH group

Question 18

3 main reactions involving alcohols

Answer 18

Oxidation, preparation of mesylates and tosylates, and protection of carbonyls

Question 19

primary alcohol

Answer 19

the carbon atom of the hydroxyl group (OH) is attached to only one single alkyl group

Question 20

secondary alcohol

Answer 20

the carbon atom of the hydroxyl group (OH) is attached to two other alkyl groups (and one hydrogen)

Question 21

tertiary alcohol

Answer 21

the carbon atom of the hydroxyl group (OH) is attached to three other alkyl groups (no hydrogens)

Question 22

diol

Answer 22

an alcohol with 2 OH groups

Question 23

if you oxidize a primary alcohol one time you will get a ______

Answer 23

aldehyde

Question 24

if you oxidize a primary alcohol TWICE you will get a ______

Answer 24

carboxylic acid

(because oxidation of an aldehyde results in a carboxylic acid)

Question 25

if you oxidize a secondary alcohol ONCE you will get a \_\_\_\_\_\_

Answer 25

ketone

Question 26

if you oxidize a tertiary alcohol ONCE you will get \_\_\_\_\_\_

Answer 26

NO REACTION! under normal conditions… (there needs to be an alpha hydrogen to oxidize the species)

Question 27

oxidation involves an ______ in oxidation state

Answer 27

increase

Question 28

chromic acid

Answer 28

Question 29

2 ways chromic acid is generated in solution

Answer 29

**the jones reagent:** sodium dichromate + sulphuric acid + water → chromic acid chromium trioxide + h3o+ + acetone → chromic acid

Question 30

describe the mechanism of alcohol oxidation (using chromic acid)

Answer 30

the hydroxyl hydrogen and chromic acid OH combine to form water a chromate ester intermediate is formed a base (water) picks up the alpha hydrogen from the alcohol, forming a double bond between the hydroxyl carbon and oxygen and kicking off the chromium atom

Question 31

during alcohol oxidation, what happens to the oxidation state of chromium?

Answer 31

it is reduced from Cr6+ (orange-ish) to Cr3+ (green-ish)

Question 32

what reagent should be used to oxidize a primary alcohol just ONCE to form an aldehyde but not carboxylic acid

Answer 32

pyridinium chlorochromate (PCC) *(milder reagent than the jones reagent)*

Question 33

which reagents could be used to oxidize a secondary alcohol to a ketone?

Answer 33

jones reagent _OR_ PCC