3.3.8 Aldehydes and Ketones

Question 1

what intermolcular force do all carbonyls have

Answer 1

permanent dipol forces

Question 2

why are smaller carbonyls soluble in water

Answer 2

smaller carbonyls can form hydrogen bonds with water molecules

Question 3

name 2 reducing agents used to reduced carbonyls

Answer 3

NaBH4 or LiAlH4

Question 4

name the mechanism, conditions and reagents for the reduction of carbonyls

Answer 4

-nucleophilic addition
-room temperature and pressure
-NaBH4 in aqueous ethanol

Question 5

what are aldehydes reduced to

Answer 5

primary alcohols

Question 6

what are ketones reduced to

Answer 6

secondary alcohols

Question 7

draw the nucleophilic addition mechanism for propanone

Answer 7

-1 intermediate step
-3 curly arrows in total
-hydride ion in initial step and hyrdogen ion
in intermediate step
-propan-2-ol is product

Question 8

why are nucleophiles attracted to carbonyls

Answer 8

the C=O bond is polarised because O is more elctronegative than C.
the slightly postive carbon attracts nucleophiles.

Question 9

describe the condition and reagents for the reduction of carbonyls using catalytic hydrogenation

Answer 9

-high pressure
-hydrogen and nickel catalyst

Question 10

what are the 2 functional groups of a hydroxynitrile

Answer 10

nitrile -CN
alcohol -OH

Question 11

name the mechanism for the reaction of carbonyls to form hydroxynitriles

Answer 11

nucleophilic addition

Question 12

describe the conditions and reagents for the reaction of carbonyls to form hydroxynitriles

Answer 12

-room temperature and pressure
-KCN and dilute sulfuric acid

Question 13

draw out the mechanism for the nucleophilic addition of propanone

Answer 13

1 intermediate step
3 curly arrows
cyanide ion in step 1 and H+ ion is step 2
2-hydroxy-2-methylpropanenitrile formed