Carbonyl compounds Flashcards
1
Q
what is reagent for reduction of Carbonyl compounds ?
A
NaBH4 in water
2
Q
what product is formed when HCN reacts with carbonyl compounds ?
A
hydroxynitrile
3
Q
How do u test for aldehydes + ketones (6)
A
- add 2-4 DNP
- see orange ppt if c=o present
- filter precipitate under reduced pressure
- recrystallise
- measure melting point
- compare with known data values
4
Q
what effect does impurities have an mpt of a substance
A
impurities LOWER mpt
5
Q
Test for aldehyde
A
- add Tollen’s reagent
- put in in water bath (80)
- silver mirror present for aldehyde
6
Q
what is a nucleophile
A
- electron pair donor
7
Q
describe what happens in stage 1 of nucleophilic addition mechanism
A
electron pair on nucleophille
attracted to δ+ carbon forming a dative covalent bond (1)
the double/π electron pair breaks (1)
electron pair now on O–
8
Q
Describe how you would make Tollens’ reagent and carry out this test in the laboratory ?
A
- silver nitrate (1)
- ammonia / ammoniacal (1)
- heat in water bath
9
Q
Flossie adds tollens reaganet to ethanal and heats identify the organic prod + provide equtions
A
- ethanoic acid cause aldehdye being oxidised
- silver ions reduced
Ag+(aq) + e– → Ag(s)
