Organic Chemistry Revision Assignment 3
(Till Hydroxy Compounds)
1.Draw the organic products formed when compound Z is treated with the following:
Z
(a)PCl5(b)Br2 water
(c)Warm alkaline aqueous I2(d)Hot acidified K2Cr2O7
(e)Hot acidified KMnO4(f)CH3CH2COOH [8 m]
1
(a)/ (b)
or
(c)
/ (d)
(e)
/ (f)
[ 1 m each]
2.Describe a simple chemical test that you could use to distinguish the following pairs of
compounds. You are to include reagents and conditions, observations and balanced equation(s) in each case. [6 m]
(a) /P /
Q
Reagents and conditions: Add PCl5 or SOCl2 at r.t.p. / PCl3 with heating
Observations: P: No white fumes
Q: White misty fumes of HClevolved
Balanced equation(s) for positive test:
Or
Reagents and conditions: Aq Br2 or liquid Br2 at r.t.p.
Observations: P: Orange or Brown Br2 decolourised, white ppt formed for aq Br2.
Q: Orange or Brown Br2 remained.
Balanced equation(s) for positive test:
Or
Reagents and conditions: Acidified K2Cr2O7, heat
Observations: P: Orange K2Cr2O7 remained
Q: Orange K2Cr2O7 turned green
Balanced equation(s) for positive test:
Neutral FeCl3 is avoided as no equation can be written
Esterification is avoided as smell is not a good distinguishing test.
(b) /R /
S
Reagents and conditions: Heat both compounds aq NaOH, then add heat with aqueous I2 + NaOH(aq).
Observations: R: Yellow ppt
S: No yellow ppt
Balanced equation(s) for positive test:
Reagents + conditions: ½ + ½
Observations: ½ m for positive observation, ½ m for negative observation
Equation: 1 m
3.Suggest how compound B can be formed from compound A. In each case, state
the reagents, conditions and intermediates (if any). [6 m]
(a) / /Acidified KMnO4 should not be used as benzoic acid will be formed.
(b) / /4.Draw the structural formulae of the compounds D, E and F.
[3 m]
[1 m each]
Accept the following structures of E and F as CH3I (without need for halogen carrier) may be
able to generate CH3+ forelectrophilic substitution on ring
(multiple substitution is acceptable also)
.