TOPIC 20 TEST MS

 1.             M1    phase or eluent or solvent (or named solvent) is moving or mobile
1
M2    stationary phase or solid or alumina/silica/resin
1
M3    separation depends on balance between solubility or affinity
(of compounds) in each phase
OR
different adsorption or retention
OR
(amino acids have) different Rf values
OR
(amino acids) travel at different speeds or take different times
1
[3]
 
2.      (a)     R: O‑H (alcohols) (1)
S: C=O or carbonyl (1)
2
(b)     aldehyde (1)   ‑CHO or RCHO (1)
1
(c)     (i)      Reason 1: TMS inert or non-toxic or volatile / easily removed
Reason 2: single (intense) peak
               peak of 12 protons
               has 12 equivalent protons
               all protons in same environment
OR
               peak / signal upfield of others
               highly shielded
               more shielded
               peak away from others or δ = 0 or low
not solvent, not cheap
any 2 reasons × (1)
(ii)     Solvent: CDCl3 or CCl4 (NOT D2O)
Reason: proton free (1)
allow no hydrogens (atoms)
NOT H+ / hydrogen ions
4
(d)     (i)       (1)
(ii)     –OH (1)
(iii)     –CH2–CH2– (1)
3
(e)      (1)
1
[11]

3.      (a)     2-chloropropanoic acid (1)
1
(b)     δ 1.72 Doublet  next to CH (1)
δ 4.44 Quartet  next to CH3 (1)
2

(c)     Two triplets (1)
1
(d)     

Allow SN1
5
(e)     (i)  
	    
(ii)     
		
(iii)     

Or anhydride
3
[12]
 
4.      (a)     5 (1)
1
(b)     2:2:2:3:3 (1)
any order but not multiples
1
(c)      (1)
1
(d)     CH3CH2 or C2H5 or ethyl (1)
δ4.13 (quartet) : CH2 peak split by CH3 / next to CH3 (1)
δ1.26 (triplet) : CH3 peak split by CH2 / next to CH2 (1)
3
(e)     CH2CH2 (1)
1
(f)      (2)
allow (1) for CH3COCH2CH2OCOCH2CH3
or CH3COOCH2CH2COCH2CH3
Must be C7H12O3
2
[9]
 
5.      (a)     (i)      There are three pairs of equivalent carbon atoms
1
(ii)     75ppm
1
(b)     (i)      4
1
(ii)     2
1
(c)     Each structure can represent a pair of cis/Z and trans/E isomers
OR
Optical isomers
1
[5]

6.     (a)     A       any C5 alkene
1
B

1
(b)     C
	
         or CH3COOH    or      HCOOCH3
1
          D
		
         or HOCH2CHO
1

(c)     E
	
1
          F
	
1
(d)     G
	
1
          H
	
1
(e)     I
	
1
          J
   NOT hex-3-ene
1
[10]