Carbonyls

Question 1

Describe structure

Answer 1

C=O bond with is polar due to electronegativity difference

Question 2

Describe bonding

Answer 2

the carbon is sp2 hybridised and 3 sigma are polar
Unhybridised 2p orbital of C is at 90 degrees
Overlaps with a 2p orbital of oxygen to form pie bond

Question 3

Addition with HCN

Answer 3

reflux in alkaline solution

Creates optical isomerism

Question 4

Reduction with NaBH4

Answer 4

Aqueous or alcoholic solution
doesn’t reduce C=C as they are polar
H-

Question 5

Reduction with H2

Answer 5

nickel and platinum catalyst and also reduces c=c as well

Question 6

Describe 2,4 dinitrophenylhydrazine

Answer 6

Makes orange crystalline derivatices different melting point
Characterise compounds
isomers have similar melting points
nucleophilic addition - elimination, adds across C=O loses, H2O

Question 7

Describe tollens reagents

Answer 7

oxidise aldehydes only - grey ppt
Ag+ + e- –> Ag (s)
Ammoniacal silver nitrate