14. Alcohols

Question 1

What is the functional group of alcohol?

Answer 1

CnH2n+1OH

Question 2

Is alcohol saturated or unsaturated?

Answer 2

Saturated

Question 3

Is alcohol polar or non-polar? Why?

Answer 3

Non-polar, because:
1. the difference in electronegativity of hydrogen and oxygen is big
2. there are weak London forces but there are stronger hydrogen bonds between the polar O-H groups

Question 4

Is alcohol water soluble? Why?

Answer 4

Soluble, because:
1. hydrogen bonds form between the polar -OH group of alcohol and water
2. as the hydrocarbon chain increases, the influence of -OH group becomes smaller

Question 5

How is alcohol’s volatility compared to the corresponding alkane?

Answer 5

Alcohols are less volatile, because:
1. hydrogen bonds hold the alcohol molecule together
2. in order to turn liquid alcohol into gas, hydrogen bonds must be broken
3. it requires more energy to break hydrogen bonds than London forces

Question 6

How is alcohol’s boiling point compared to the corresponding alkane?

Answer 6

Alcohol has a higher boiling point, because:
1. hydrogen bonds hold the alcohol molecule together
2. in order to turn liquid alcohol into gas, hydrogen bonds must be broken
3. it requires more energy to break hydrogen bonds than London forces

Question 7

How do primary alcohols look like?

Answer 7

The -OH group is attached to a carbon atom that is attached to two hydrogen atoms and one alkyl group.

Question 8

How do secondary alcohols look like?

Answer 8

The -OH group is attached to a carbon atom that is attached to one hydrogen atom and two alkyl groups.

Question 9

How do tertiary alcohols look like?

Answer 9

The -OH group is attached to a carbon atom that is attached to no hydrogen atom and three alkyl groups.