3.3.8-9 Aldehydes + ketones; Carboxylic acids + derivatives

Question 1

what mechanism do aldehydes + ketones undergo?

Answer 1

nucleophilic addition

Question 2

what are the reagents + conditions for nucleophilic addition (with CN-?)

Answer 2

reagent - KCN conditions - reflux

Question 3

what is produced when an aldehyde/ketone reacts with KCN?

Answer 3

hydroxynitrile

Question 4

why is KCN hazardous but used instead of HCN?

Answer 4

• KCN is toxic/poisonous
• HCN is a weaker acid so has more difficulty dissociating, meaning ionic KCN produces more of the nucleophile CN-

Question 5

what do you use to reduce aldehydes/ketones into alcohols?

Answer 5

NaBH4 (sodium tetrahydridoborate)

Question 6

what are the reagents + conditions for reduction using NaBH4?

Answer 6

reagents: NaBH4
conditions: aqueous or alcoholic solution
mechanism: nucleophilic addition

Question 7

what nucleophile is used when undergoing reduction?

Answer 7

hydride ion (H-)

Question 8

why does NaBH4 reduce aldehydes/ketones but not alkenes?

Answer 8

the C=C bond is electron rich and has a high electron density, meaning that it is repelled by the negatively charged H- ion.

Question 9

what are the reagents + conditions for reduction with hydrogen?

Answer 9

reagent: hydrogen
conditions: nickel or platinum catalyst

Question 10

why do carbonyl compounds undergo nucleophilic addition?

Answer 10

• the O is more elctronegative than the C so it pulls the bonding pair of electrons to itself
• ## C (delta +ve is electron deficient so it is attracted to nucleophiles)

Question 11

what is the functional group for an acyl chloride?

Answer 11

R-C=O-Cl

Question 12

what is the functional group for an acid anhydride?

Answer 12

(RCO)2O

Question 13

what is the functional group for an amide?

Answer 13

R-C=O-NH2

Question 14

what do metals and acids react to form?

Answer 14

salts + hydrogen

Question 15

what are the reagents + conditions for esterification?

Answer 15

reagent - concentrated H2SO4 catalyst
condition - heat under reflux

Question 16

what is the word equation for esterification using acid anhydrides?

Answer 16

acid anhydride + alcohol -> ester + carboxylic acid?

Question 17

write out the symbol equation for:
(CH3CH2CO)2O + CH3CH2OH
[propanoic anhydride + ethanol)

Answer 17

CH3CH2COOCH2CH3 + CH3CH2COOH
[ethyl propanoate + propanoic acid]

Question 18

what do reactions involving acyl chlorides produce and what is observed?

Answer 18

all produce HCl gas, which is acidic and toxic. white misty fumes are involved

Question 19

what do acyl chlorides and water produce?

Answer 19

carboxylic acid + HCl

Question 20

what do acyl chlorides and ammonia produce?

Answer 20

primary amide + HCl

Question 21

what do acyl chlorides and primary amines produce?

Answer 21

amide + HCl

Question 22

how are acyl chlorides made?

Answer 22

react carboxylic acid with thionyl chloride - SOCl2

CH3CH2COOH + SOCl2 -> CH3CH2COCL + SO2 + HCl