Organic Chemistry 2

Question 1

7What group do aldehyde and ketone contain?

Answer 1

A carbonyl group

Question 2

Why can’t aldehyde and ketone form hydrogen bonds with each other?

Answer 2

Because they don’t have a polar O-H bond

Question 3

Can aldehyde and ketone hydrogen bond with water?

Answer 3

Yes, because although they don’t have polar OH groups, they have a lone pair of electrons on the O of the C=O group

Question 4

How can you test for an aldehyde with tollen’s reagent?

Answer 4

• Tollens reagent is a colourless solution of silver nitrate dissolved in aqueous ammonia.
• If it’s heated in a test tube with an aldehyde, a silver mirror forms after a few minutes

Question 5

What is the colour change when you heat an aldehyde with acidification potassium dichromate ions?

Answer 5

Colour change from orange to green

Question 6

What can an aldehyde be reduced back to?

Answer 6

A primary alcohol

Question 7

What reducing agent is needed for the reduction of an aldehyde to a primary alcohol?

Answer 7

LiAlH4 in dry ether ([H])

Question 8

What can a ketone be reduced to?

Answer 8

A secondary alcohol

Question 9

What type of reaction is the reduction of an aldehyde to a primary alcohol?

Answer 9

A nucleophillic addition reaction

Question 10

What does hydrogen cyanide react with carbonyl compounds to give?

Answer 10

Hydroxynitriles

Question 11

What are hydroxynitriles?

Answer 11

Molecules with a CN and an OH group

Question 12

What type of reaction is the reaction between hydrogen cyanide and carbonyls?

Answer 12

Nucleophilic addition

Question 13

Draw the mechanism for the reaction between hydrogen cyanide and a carbonyl

Answer 13

In book

Question 14

How do you test for a carbonyl group using 2,4-DNPH?

Answer 14

-The 2,4-DNPH is dissolved in methanol and conc sulfuric acid.

• It reacts to form a bright orange precipitate of a carbonyl group

Question 16

Which type of carbonyl react with iodine?

Answer 16

Those that contain a methyl carbonyl group

Question 17

What happens when carbonyl with a methyl carbonate group react with iodine?

Answer 17

You get a yellow precipitate of CHI3 and an antiseptic smell

Question 18

RCOCH3 + 3I2 + 4OH- ->

Answer 18

RCOO- + CHI3 + 3I- + 3H20

Question 19

What can form with pure liquid carboxylic acids ?

Answer 19

Dimers

Question 20

What is formed when you hydrolyse a nitrile?

Answer 20

A carboxylic acid and an ammonium chloride

Question 21

How do you hydrolyse a nitrile?

Answer 21

• You reflux the nitrile with dilute HCl and then distilling of the carboxylic acid

Question 22

CH3C=N + 2H20 + HCl ->

Answer 22

CH3COOH + NH4Cl

Question 23

What happens when carboxylic acid reacts with a base?

Answer 23

A salt and water is formed

Question 24

What happens when a carboxylic acid reacts with carbonate or hydrogencarbonate ions?

Answer 24

A salt, water and CO2 are formed

Question 25

CH3COOH + NaOH ->

Answer 25

CH3COONa + H2O

Question 26

2CH3COOH + Na2CO3 ->

Answer 26

2CH3COONa + H20 + CO2

Question 27

CH3COOH + NaHCO3 ->

Answer 27

CH3COONa + H20 + CO2

Question 28

What is used to reduce carboxylic acid to a primary alcohol?

Answer 28

The powerful reducing agent LiAlH4 in dry ether

Question 29

What do you get when you react a carboxylic acid with PCl5?

Answer 29

An acyl chloride, POCl3 + HCl

Question 30

RCOOH + PCl5 ->

Answer 30

RCOCL + POCL3 + HCL

Question 31

What is the functional group of an ester?

Answer 31

COO

Question 32

What does the name of the ester come frome?

Answer 32

- The first part of the name comes from the alcohol - The second part of thr name comes from the carboxylic acid

Question 33

Carboxylic acid + alcohol-> (In presence of an acid catalyst)

Answer 33

Ester and water

Question 34

What type of reaction is esterification?

Answer 34

A condensation reaction

Question 35

What happens in base hydrolysis of an ester ?

Answer 35

The ester is refluxed with a dilute alkali such as sodium hydroxide. A carboxylate ion and an alcohol are produced

Question 36

What is the functional group of acyl chlorides?

Answer 36

COCl

Question 37

Ethanoyl chloride + water ->

Answer 37

Ethanoic acid

Question 38

Ethanol chloride + methanol ->

Answer 38

Methyl ethanoate + HCl

Question 39

Ethanoyl chloride + Concentrated ammonia->

Answer 39

Ethanamide + HCl

Question 40

Ethanoyl chloride + methylamine ->

Answer 40

N-methlyethanamide

Question 41

Acyl chloride + water ->

Answer 41

Carboxylic acid

Question 42

Acyl chloride + alcohol->

Answer 42

Ester + HCl

Question 43

Acyl chloride + concentrated ammonia ->

Answer 43

Ethanamide + HCl

Question 44

Acyl chloride + amine->

Answer 44

N-methly ethanamide