Alcohols

Question 1

Alcohol

Answer 1

Alcohols contain one or more hydroxyl groups (OH groups) substituted for hydrogen atoms along the carbon chain.

Question 2

Enol

Answer 2

Organic compounds with the hydroxyl group attached to a vinylic carbon

Question 3

Phenol

Answer 3

Phenol is an organic compound in which a hydroxyl group is directly bonded to one of the carbon atoms of an aromatic ring.

Question 4

What kind of organic compound is this?

Answer 4

Enol

Question 5

What kind of organic compound is this?

Answer 5

Alcohol

Question 6

What kind of organic compound is this?

Answer 6

Phenol

Question 7

What is the suffix used to denote an alcohol?

Answer 7

-ol

Question 8

What does R represent in this image?

Answer 8

It denotes the alkyl group of an alcohol that the -OH group is bonded to

Question 9

What is the organic compound pictured here?

Answer 9

Methanol or methyl alcohol

Question 10

Answer 10

Formation reaction for methanol

Question 11

Answer 11

Synthesis of Ethanol (This is an example of an addition reaction)

Question 12

What kinds of reactions are common for alkyl halides but not for aryl halides?

Answer 12

Nucleophilic substitution and elimination reactions

Question 13

What group is not affected by substitution or elimination reactions?

Answer 13

The phenolic hydroxyl group

Question 14

What is the functional group of an alcohol called?

Answer 14

Hydroxyl group

Question 15

What is a primary alcohol?

Answer 15

An alcohol where the carbon which carries the -OH group is only attached to one alkyl group.

Question 16

What is a secondary alcohol?

Answer 16

An alcohol where the carbon with the -OH group attached is joined directly to two alkyl groups.

Question 17

Answer 17

Primary Alcohol

Question 18

Answer 18

Secondary Alcohol

Question 19

Answer 19

Tertiary Alcohols

Question 20

Naming Alcohols - Step 1

Answer 20

Find the longest chain containing the hydroxy group (OH). If there is a chain with more carbons than the one containing the OH group it will be named as a subsitutent.

Question 21

Naming Alcohols - Step 2

Answer 21

Place the OH on the lowest possible number for the chain. With the exception of carbonyl groups such as ketones and aldehydes, the alcohol or hydroxy groups have first priority for naming.

Question 22

Naming Alcohols - Step 3

Answer 22

When naming a cyclic structure, the -OH is assumed to be on the first carbon unless the carbonyl group is present, in which case the later will get priority at the first carbon.

Question 23

Naming Alcohols - Step 4

Answer 23

When multiple -OH groups are on the cyclic structure, number the carbons on which the -OH groups reside.

Question 24

Naming Alcohols - Step 5

Answer 24

Remove the final e from the parent alkane chain and add -ol. When multiple alcohols are present use di, tri, etc. before the -ol, after the parent name. If a carbonyl group is present, the -OH group is named with the prefix “hydroxy,” with the carbonyl group attached to the parent chain name so that it ends with -al or -one.

Question 25

Suffix for an alcohol that has 2 hydroxyl groups and may be called a glycol

Answer 25

-diol

Question 26

What is the name for a -OH group?

Answer 26

Hydroxyl group

Question 27

Define acid ionization constant (Ka)

Question 28

What is the difference between the boiling point of alkanes and alcohols?

Answer 28

The boiling point of an alcohol is always significantly higher than that of the similar alkane.

Question 29

What happens to the boiling point of alcohols as the number of carbon atoms increase?

Answer 29

The boiling point increases.

Question 30

Define hydrogen bond

Answer 30

Electrostatic force of attraction between a hydrogen atom and a strongly electronegative element (like fluorine, oxygen or nitrogen) or group

Question 31

Define van der Waals forces

Answer 31

Distance dependent interaction between atoms and molecules caused by permanent or temporary dipoles. It results from the mutual repulsion between the atoms' electron clouds.

Question 32

Define dipole-dipole interactions

Answer 32

It is when two dipolar molecules interact with each other through space, the partially negative portion of one of the polar molecules is attracted to the partially positive portion of the second polar molecule.

Question 33

Describe how the boiling point relates to the van der Waals forces in alcohols

Answer 33

van der Waals dispersion forces increase as the size of the alcohol increases causing the attractions to get strong due to the increased amount of electrons present. This increases to size of the temporary dipoles formed as well. It therefore takes more energy to overcome the dispersion forces, which causes an increased boiling point.

Question 34

Why are small alcohol molecules soluble in water (less than 4C) and larger (4C and greater) not?

Answer 34

The main bonding force in water and small alcohol molecules are hydrogen bonds. These bonds must be broken to form new bonds between the water and the alcohol. The energy released when new bonds form is roughly equal to that required for when they break. At the size of the alcohol increases, the hydroxyl group forms bonds with water, but the hydrocarbon tail does not. This means hydrogen bonds are broken and not reformed, which decreases the enthalpy available. Weak van der Waals forces form instead.

Question 35

What is the order of acidity for liquid alcohols?

Answer 35

Water > Primary > Secondary > Tertiary Larger anions of alcohols are less solvated than smaller ions b/c fewer solvent molecules can surround the -O in the ion

Question 36

What is the order of acidity for gaseous alcohols?

Answer 36

Tertiary > Secondary > Primary Gaseous ions are more stable as the size of the R group increases

Question 37

How do alcohols behave as bases?

Answer 37

Alcohols are bases similar in strength to water and accept protons from strong acids

Question 38

What kind of acids do alcohols and phenols behave as?

Answer 38

Compounds like alcohols and phenol which contain an -OH group attached to a hydrocarbon are very weak acids. Alcohols are so weak they can be ignored, but phenol is sufficiently acidic for it to have recognizably acidic properties.

Question 39

Why can phenol act as an acid?

Answer 39

- Sufficiently acidic - Phenoxide ion is stable enough to form - The charge is delocalized around the ring, the lone e- pair is attracted to the highly EN -O