Alcohols and phenols

Question 1

Alcohols

Answer 1

organic compounds which contain a hydroxyl group (−OH) attached to a saturated carbon atom. R is a substituent (which generally refers to alkyl groups).

Question 2

Types of alcohols determined

Answer 2

position of the hydroxyl functional group

Question 3

Primary alcohols

Answer 3

hydroxyl group (–OH) is attached to a carbon atom with at least two hydrogen atoms
only occur when the hydroxyl group is at the end of the molecule chain

Question 4

Secondary alcohols

Answer 4

hydroxyl group (-OH) is attached to a carbon with only one hydrogen atom attached
happen somewhere in the middle of a carbon chain

Question 5

Tertiary alcohols

Answer 5

hydroxyl group is attached to a carbon with no hydrogen atoms attached
hydroxyl group is joined to the same carbon atom as a branch

Question 6

Multiple hydroxyl groups names

Answer 6

Alcohols with two hydroxyl groups are called diols
Alcohols with three hydroxyl groups are called triols

Question 7

Alcohols easily undergo oxidation

Answer 7

Primary alcohols oxidize to form aldehydes, and aldehydes again oxidize to produce carboxylic acids.
Secondary alcohols can only oxidize once, which results in ketones.
Tertiary alcohols cannot be oxidized, as the carbon atom has no orbitals left for forming a double bond with the oxygen atom.

Question 8

Properties of alcohols

Answer 8

Compared with alkanes, alcohols have significantly higher boiling points

Question 9

Phenol

Answer 9

type of alcohol where the hydroxyl group is bound to an aromatic ring
Phenol and its chemical derivatives are the key ingredient to many compounds such as nylon, detergents, herbs, and pharmaceutical drugs.
Phenols occur either as colourless liquids or white solids at room temperature and may be highly toxic and caustic.

Question 10

alcohols form hydrogen bonds with other compounds like water

Answer 10

hydroxyl group

Question 11

alcohols solubility

Answer 11

alkyl groups are considered to be non-polar
have a higher solubility in water when the carbon chain of the substituent (R) is small
alcohols like methanol or ethanol tend to mix well with water, whereas alcohols with more than four carbons (e.g. pentanol, hexanol) are considered insoluble in water

Question 12

alcohols as acids

Answer 12

very weak acids
pH of an alcohol solution is almost neutral, they are still able to react with strong bases
Phenol is a relatively strong acid compared to alkyl alcohols

Question 13

phenols solubility compare to alcohols

Answer 13

form stronger hydrogen bonds = more soluble in water + have higher boiling
points.

Question 14

Phenols used

Answer 14

household products
intermediates for industrial synthesis
used (in low concentrations) as a disinfectant in household cleaners and in mouthwash.
Phenol may have been the first surgical antiseptic.
starting material to make plastics, explosives such as picric acid, and drugs such as aspirin.

Question 15

Phenol is quite toxic

Answer 15

concentrated solutions cause severe but painless burns of the skin and mucous membranes