4.3 Alcohols & Phenols Flashcards
1
Q
Draw a phenol
A
2
Q
Explain the reactivity of phenol (diagram too)
A
- lone pair on the oxygen is drawn to the ring
- increases electron density of the ring, activating it
- ring is able to induce dipoles
3
Q
Describe the test for phenols
A
- Ferric chloride test, FeCl3
- lead to deep purple solution
- add bromine give white ppt
4
Q
Explain the reactivity of phenol
A
- phenol is highly reactive due to the overlap of p-orbitals of the oxygen from the hydroxyl group and the p-orbitals of the carbons on the benzene ring of phenol
- overlapping causes lone pair on oxygen to be drawn to the ring
- increases electron density of the ring, activating it and making it able to induce dipoles
5
Q
Explain the reactivity of benzene
A
- not very reactive
- 3 double bonds
- double bonds must be broken
- molecules reacting with it must be +ve to attract electrons in the bond and break them
6
Q
Explain the reactivity of cyclohexene
A
- very reactive
- only one double bonds must be broken
- can easily induce dipoles due to high delocalisation
7
Q
Primary alcohol
A
One carbon bonded to the C-OH group
8
Q
Secondary alcohol
A
Two carbon atoms bonded to the C-OH group
9
Q
What are the methods of forming alcohols?
A
- halogenoalkanes by a substitution reaction
- reducing aldehydes, ketones or carboxylic acids
10
Q
Draw the nucleophilic substitution of a halogenoalkane
A
11
Q
What is used in carbonyl reduction?
A
- sodium tetrahydridiborate / NaBH4 (aldehyde and ketones)
- lithium aluminium hydride (carboxylic acids)
12
Q
Primary alcohol mechanism
A
Primary —> aldehyde —> carboxylic acid
- H+/Cr2O7 at each stage
- distillation in first stage
- reflux to go alcohol to carboxylic acid
13
Q
Secondary alcohol mechanism
A
Secondary —> ketone
- H+/Cr2O7
14
Q
Tertiary alcohol mechanism
A
No change occurs
