Section 7 - Alcohols

Question 1

What functional group do alcohols have?

Answer 1

-OH

Question 2

What are the first three alcohols?

Answer 2

Methanol, Ethanol, Propanol

Question 3

For many alcohols, the -OH group can be put in different positions along the chain. What does this mean they are able to form?

Answer 3

Isomers

Question 4

Whether an alcohol is called primary, secondary or tertiary depends on ___?

Answer 4

what other groups surround the carbon atom that the -OH group is attached to

Question 5

Oxygen is an electro___________ element

Answer 5

negative

Question 6

Oxygen is an electronegative element. What does this mean in terms of the bonding of alcohols? (2)

Answer 6

• It draws the bonding electrons towards itself in the C-OH bond, meaning that alcohols are normally polar molecules.
• It also draws electrons away from the hydrogen atom in the -OH group, giving the hydrogen atom a slightly positive charge. This charge attracts the lone pairs of electrons on oxygen atoms in other nearby alcohol molecules, which forms a hydrogen bond.

Question 7

Hydrogen bonds have a big effect on the properties of alcohols. What 2 properties are these?

Answer 7

1) Alcohols are soluble in water
2) Alcohols have high boiling and melting points compared to alkanes or alkenes of a similar size. This is because hydrogen bonds are the strongest type of intermolecular bond, so they need lots of energy to break.