Alcohols

Question 1

What is the general formula of saturated mono-alcohols

Answer 1

CnH2n+1OH

Question 2

How do you name alcohols

Answer 2

Same as alkenes but ending in-ol. A number may be required to indicate the position of the hydroxyl group (propan-1-ol, propan-2-ol)

Question 3

How do you name a compound with 2 OH groups

Answer 3

-diol

Eg ethane-1,2-diol

Question 4

How do you name a compound with 3 OH groups

Answer 4

-triol

Eg propan-1,2,3-triol

Question 5

If a molecule contains another, more oxidised functional group, how can alcohols be named

Answer 5

Using the prefix hydroxy-

Question 6

How are alcohols classified

Answer 6

According to the carbon atom that the hydroxyl group is attached to

Question 7

What is a primary alcohol

Answer 7

When the carbon attached to the OH has one other carbon attached

Question 8

What is a secondary alcohol

Answer 8

When the carbon attached to the OH has two other carbons attached

Question 9

What is a tertiary alcohol

Answer 9

When the carbon attached to the OH group has 3 other carbons attached

Question 10

What do we consider alcohols to be

Answer 10

Alkylated water

Question 11

Why are alcohols considered to be alkylated water

Answer 11

The alkyl groups acts like an alkane (non-polar, dominated by van dear Waals forces) and the hydroxyl group acts like a water (polar, dominated by hydrogen bonding)

Question 12

Why do alcohols have much higher melting points and boiling points than alkanes

Answer 12

Because hydrogen bonding is a strong interaction

Question 13

In which alcohols is the hydrogen bonding effect strongest

Answer 13

Small alcohols

Question 14

What other functional groups can the hydroxyl functional group be converted into

Answer 14

Halogenoalkane, aldehyde, carboxylic acid, alkene, ketone

Question 15

What is alcohol halogenation

Answer 15

Treatment with PX3 forms a halogenalkane

Question 16

What does ethanol and PCl3 form

Answer 16

Chloroalkane

Question 17

What does ethanol and PBr3 form

Answer 17

Bromoalkane

Question 18

What does ethanol and PI3 form

Answer 18

Iodoalkane

Question 19

What is alcohol dehydration

Answer 19

Treatment of alcohols with strong acid causes dehydration. Protonation of the alcohol makes it into a good leaving group

Question 20

What does dehydration of ethanol form

Answer 20

Diagram

Question 21

What does oxidation of alcohols form

Answer 21

Aldehydes, ketones or carboxylic acids

Question 22

What happens when a primary alcohol is oxidised once

Answer 22

Forms aldehyde

Question 23

What happens when a primary alcohol is oxidised twice

Answer 23

Forms an aldehyde then a carboxylic acid

Question 24

What we alcohols

Answer 24

Alcohols are compounds that contain a hydroxyl group

Question 25

What happens when a tertiary alcohol is oxidised

Answer 25

No reaction

Question 26

What is a test for primary and secondary alcohols

Answer 26

Potassium permanganate changes from purple to brown showing alcohol was present

Question 27

Why is conversion of primary alcohol to aldehyde oxidation

Answer 27

It is the loss of two hydrogen atoms

Question 28

Why is aldehyde to carboxylic acid oxidation

Answer 28

Oh is the gain of oxygen

Question 29

What does the reaction of an alcohol with a carboxylic acid form

Answer 29

An ester

Question 30

What type of reaction is ester formation from an alcohol

Answer 30

Condensation reaction

Question 31

How are polyesters formed

Answer 31

Reaction of a diol with a di-acid forms a polyester

Question 32

Apart from reactions with diols how else can polyesters be formed

Answer 32

From hydroxyacids

Question 33

What happens when a secondary alcohol is oxidised

Answer 33

Forms a ketone