Unit 4.3 Alcohols and Phenol

Question 1

Tips wise, how do i even go abouts efficiently learning mechanisms n stuff

Answer 1

Don’t make the same mistake for physics
(totally unrelated to the question)

The whiteboard merchant.

Question 2

What’s the difference between primary alcohols and secondary alcohols?
(2 thingies)

Answer 2

• Primary alcohol = OH technically on either side
• Secondary alcohol = OH on the “second” carbon

Question 3

How do u convert halogenoalkanes into alcohols?
(2 similars + 1 thing)

Answer 3

• Nucleophilic substitution
• Hydrolysis
• Forms a primary alcohol

Question 4

What are the conditions required to convert halogenoalkanes into alcohols?
(2-way)

Answer 4

• Heat to reflux
• with _aq sodium hydroxide

Question 5

Class of mechanism of converting halogenoalkanes into alcohols?

Answer 5

Nucleophilic substitution

Question 6

Show me the equation and mechanism using potassium hydroxide and 2-bromobutane
(Halogenoalkanes into alcohols)
(Hm.)

Answer 6

The whiteboard buddy

C₄H₉Br + KOH -> C₄H₉OH + KBr

Question 7

Show nucleophilic substitution for:
1. CN^- and 1-chloropropane
2. NH₃ and 1-bromobutane
(Heavily whiteboard based)

Answer 7

• No eqn :(
• But u could at least try form the equation right?:

H₃CCH₂CH₂Cl + CN^- -> H₃CCH₂CH₂CN + Cl^-

Couldn’t tell u for 2.

Question 8

What’s the purpose of the reduction of aldehydes and ketones?

Answer 8

Form primary and secondary alcohols

Question 9

What do u need to reduce ketones and aldehydes?
(2 compounds)

Answer 9

• Sodium borohydride (NaBH₄
• Lithium aluminium hydride (LiAlH₄)

Question 10

What’s the jig with Lithium aluminium hydride?
(2-way)

Answer 10

• LiAlH₄ must be dissolved
• in ethoxyethane (dry)

Question 11

How to tell if it’s oxidation or reduction within a chemical equation?
(2 features)

Answer 11

• [O] = oxidation
• [H] = reduction

Question 12

What are ketones reduced to?

Answer 12

Secondary alcohols

Question 13

Show chemical equation of the reduction of propan-2-one indicating conditions required.
(You should use a whiteboard)

Answer 13

CH₃(C=O)CH₃ + Z[H] -> CH₃CH(OH)CH₃

Question 14

Show the mechanism of the reduction of propan-2-one
(Whiteboard?)

Answer 14

Where’s your whiteboard

Question 15

What’s the mechanism used for the reduction of ketones?

Answer 15

Nucleophilic addition

Question 16

What are aldehydes reduced to?

Answer 16

Primary alcohols

Question 17

Show chemical equation of the reduction of ethanal indicating conditions required.
(You should use a whiteboard)

Answer 17

CH₃C(=O)H + 2[H] -> CH₃CH(OH)H

Question 18

Show the mechanism of the reduction of ethanal
(Whiteboard?)

Answer 18

Where’s your whiteboard

Question 19

What’s the mechanism used for the reduction of aldehydes?

Answer 19

Nucleophilic addition

Question 20

What other compound can be reduced to primary alcohols?

Answer 20

Carboxylic acids

Question 21

What must u use (and its conditions) to reduce carboxylic acid to primary alcohols?
(3 things)

Answer 21

• Lithium aluminium hydride (LiAlH₄)
• Must be used under anhydrous conditions
• Dissolved in ethoxyethane (diethyl ether)

Question 22

Show chemical equation of the reduction of propanoic acid indicating conditions required.
(You should use a whiteboard)

Answer 22

H₃CCH₂C(=O)OH + 4[H] -> H₃CCH₂CH₂(OH) + H₂O
(LiAlH₄)

Question 23

What is the “Lucas Test”?
(2-way)

Answer 23

• Test to distinguish between
• the different classes of alcohols

Question 24

How is the Lucas Test performed?
(2 steps each w/ halves)

Answer 24

1) Small amount of zinc chloride added as catalyst
1.5) & concentrated hydrochloric acid
2) Observe cloudiness
2.5) … the formation of insoluble chloro-compound

Question 25

What do u observe for primary alcohols with Lucas Test? (2 things)

Answer 25

- Stays colourless - No indication of a reaction

Question 26

What do u observe for secondary alcohols with Lucas Test? (2 things)

Answer 26

- Cloudiness - Slowly appears

Question 27

What do u observe for tertiary alcohols with Lucas Test? (2 words)

Answer 27

- Cloudiness - Instantaneous

Question 28

Show the chemical equation for: 1. Primary alcohol reacting with HCl (Lucas Test) (You should use a whiteboard)

Answer 28

1° = H₃CH₂OH + HCl -> H₃CCH₂Cl + H₂O

Question 29

Show chemical equation for: 2. Secondary alcohol reacting with HCl (Lucas Test) (You should use a whiteboard)

Answer 29

2° = H₃CCH(OH)CH₃ + HCl -> H₃CCHBrCH₃ + H₂O

Question 30

What would u need to prepare bromoalkanes? (2 things)

Answer 30

- Mixture of potassium bromide, - and concentrated sulfuric acid

Question 31

What is "in situ" for the preparation of bromoalkane? (2-way)

Answer 31

- Produces hydrogen bromide (HBr) - that can attack the alcohol

Question 32

Chemical equation of the preparation of bromoalkanes? (You should use a whiteboard)

Answer 32

H₃CCH₂OH +HBr -> H₃CCH₂Br + H₂O

Question 33

Chemical equation of the preparation of bromoalkanes "in situ"? (You should use a whiteboard)

Answer 33

2KBr + H₂SO₄ -> **2HBr** + K₂SO₄

Question 34

What does the reaction of Alcohols with Ethanoyl chloride form? (2-way)

Answer 34

- Allows formation of sweet smelling compounds: - Esters

Question 35

Purpose of esters? (2 features)

Answer 35

- Used as solvents - Flavourings and perfumes

Question 36

Chemical equation of the reaction between propan-1-ol and ethanoyl chloride? (You should use a whiteboard)

Answer 36

H₃CCH₂CH₂OH + H₃CC(=O)Cl -> H₃C(=O)OCH₂CH₂CH₃ + HCl

Question 37

What does the reaction of Alcohols with Carboxylic acid form?

Answer 37

... Esters...

Question 38

What must be needed for the reaction of Alcohols with Carboxylic acid? (1 thing + 2-way)

Answer 38

- Heat - Small quantity of concentrated sulfuric acid - ... that acts as a catalyst

Question 39

How does the carboxylic acid undergo nucleophilic attack during the reaction with alcohols? (2-way + 1 thing)

Answer 39

- Acid protonates the carboxylic acid - aka the conc. sulfuric acid - Nucleophilic attack by an alcohol

Question 40

How is the ester gained after the reaction of alcohols with ethanoyl chloride & carboxylic acids? (3 things)

Answer 40

- Distilled off soon as they formed - To draw equilibrium to the right hand side - **Only if they have low molecular masses**

Question 41

How do esters have lower boiling points than the alcohols and carboxylic acids, from which they are formed...

Answer 41

They don't form hydrogen bonds

Question 42

Describe phenol (2 things + 2-way)

Answer 42

- Simplest aromatic alcohol - Toxic white solid (no contact with skin) - Forms slightly acidic solution - .... in water

Question 43

Show me a diagram explaining why phenol is slightly acidic

Answer 43

Where's your whiteboard. "Phenol" ⇌ Phenoxide ion + H⁺ or H₃O⁺

Question 44

How can the phenoxide ion charge be stabilised? (2-way)

Answer 44

- Via delocalisation through - the ring system

Question 45

What's the pH of _aq of phenol?

Answer 45

5 - 6 pH

Question 46

What does the acidity of phenol allow the creation of? Show me.

Answer 46

Salt: acid + alkali = salt + water

Question 47

Show the equation of phenol w/ sodium hydroxide to form sodium phenoxide (You should use a whiteboard)

Answer 47

Where's your whiteboard? "Phenol" + NaOH -> "Sodium phenoxide" + H₂O

Question 48

What are 2 tests to "test" for phenol?

Answer 48

- Reaction with Br/Bromine water - Reaction with iron(III) chloride solution

Question 49

What's the observation with phenol reacting with Br/Bromine water? (2 things)

Answer 49

- White ppt forms - Br solution/water decolourises

Question 50

Equation of phenol reacting with Br/bromine water? (You should use a whiteboard)

Answer 50

Where's your whiteboard? Phenol + 3Br₂ -> "What." + 3HBr

Question 51

What's the colour of FeCl₃ solution (Iron (III) chloride solution) (2-way...?)

Answer 51

- Red/brown - (yellow 0.1M)

Question 52

What colour complex is gained from phenol reacting with FeCl₃?

Answer 52

Violet

Question 53

Which test for phenol doesn't do colouration to an alkyl alcohol?

Answer 53

Reaction with iron(III) chloride solution (FeCl₃)

Question 54

Why do we need to use an **acid chloride** to esterify a phenol?

Answer 54

Doesn't react with carboxylic acids

Question 55

Show the equation of phenol with ethanoyl chloride (You should use a whiteboard)

Answer 55

H₃C(=O)Cl + phenol -> "Phenol ethanol" + HCl

Question 56

MUST USE ur book for most equations + mechanisms.

Answer 56

And, always spam ppq