Hellen
JC1 Truth 2/4/20
Assignment on carbonyl compounds
Submit by 3pm today.
1. How do you prepare propanal from propan-1-ol in laboratory? (2)
with dilute
potassium di chromate ch ) , acidity it
it
with the acidified
acid and heat
Oxidising agent
sulfuric
:
gently
di chromate solution
.
2. Name two reagents and their conditions to convert ethanal to ethanol. (2)
I. aqueous alkaline solution of Nat B4
2.li A IH4
in
dry
ether → must be in
→
room
must
be
warmed
temperature
3. Write the equation and conditions to convert butanenitrile to butanoic acid (2)
Must be heated under reflux
↳ H , CN1-2HY
HC1 -7
-1
with
GHz
dilute hydrochloric acid
NH44
C0 0HT
4. Write the equation and conditions to convert butanenitrile to butanamine (2)
Using sodium
↳ Hy CN
t
and
4 LH3
ethanol
→
CH3
OH , CH
,
LH
,
NH
,
5. Write the mechanism for the nucleophilic substitution between propanal and HCN. (2)
CH3 CH2
CH3
I
not not
[
H
=
If
0
-
:c N
→
CH
-
,
c-
OFF IN
CY3
→
CH3
-
C
I
1
CN
CN
-
o
-
H
t
ion
6. How HCN is prepared for reaction in Q5? Write the equation (2)
in situ
the reaction
is
HCN
by
generated
Na CN and
dilute sulfuric acid
of
.
7. Write the equation between 2,4-DNPH and propanal.(2)
"
µ
"
"
µ,
-
✓
02N
8. Complete the table below.(4)
Reagent
N02
⑦
-
-
µ
=
"
C
N
'
Ht
H20
,
H
Observation with CH3CHO
aldehyde
Observation with
CH3COCH3
ketone
2,4-DNPH
Deep orange precipitate is formed
Deep orange precipitate is formed
T e eage
Silver nitrate in excess
ammonia
Mirror inside tube
Remains colourless
Feh i g Solution
Warmed alkaline solution
of copper (II) ion
Clear
red 1
blue solution turns into
No reaction ( except for ethanol )
Triiodomethane reaction
Warmed Alkaline solution
of iodine
the solution remains blue
orange ppt
yellow
precipitate
formed
9. Triiodomethane reaction can be also used to test for specific alcohols. Explain. (2)
This test
atom
can
be used to
adjacent
to a
presence of a secondary alcohol group on the carbon
)
This
CH3 CH C0H group is firstly oxidised by the alkaline
group
a
ketone , RC0 CH3 which then gives
forms a
identify
methyl
iodine solution This oxidation
.
yellow precipitate
.
the
.
methyl
,