TOPIC 19 TEST MS
 
1.			    (a)     (i)      
 
Allow CO2- and NH2+
1
(ii)     NOTE − Two marks for this clip
M1 for alanine section bonded through N
M2 for alanine section bonded through C
But penalise error in proline ring
1
 
Allow MAX 1 for correct tripeptide in polymer structure
1
(b)     (i)      3-methylpent-2-ene
Ignore E-Z, commas, spaces or missing hyphens
1
(ii)     4-amino-3-methylbutanoic acid
Ignore commas, spaces or missing hyphens
1
(iii)    
or any polyamide section containing
8 carbons plus two C=O plus two N-H, such as

Trailing bonds are required
1
(iv)    Non polar OR no polar groups / bonds (for attack by water / acids / alkalis / nucleophiles or for hydrolysis)
C-C bonds are strong
1
[7]
2.			     (a)    

Allow −NH3+ and +NH3−
1
(b)     

Allow protonated form, i.e. −NH3+ or +NH3−
1
(c)     

Allow – CO2–
1
(d)     

Allow zwitterion with any COO−
Allow use of “wrong” COOH

1
[4]

3.	
		(a)  	   (i)

These four only
1
(ii)

Allow − NH3+ and +NH3−
1
(iii)    2-amino-3-hydroxybutanoic acid
Ignore 1 in butan-1-oic acid
Do not penalise commas or missing hyphens
Penalise other numbers
1
(iv)

Allow –NH3+ and +NH3−
1
(b)     (i)      Condensation
Allow polyester
1
(ii)     propane-1,3-diol
Must have e
Allow 1,3-propanediol
1

(c)     (i)      Addition
Not additional
1
(ii)

Allow monomers drawn either way round
Allow bond to F in CF3
1
OR

1 for each structure within each pair
1
(d)     c
If wrong, CE = 0
1
C-C or C-F bonds too strong
1
[11]

4.         (a)     (i)      

(Ignore n or brackets, but trailing bonds are essential)
1
(ii)     Addition or radical
1
(b)     (i)      2-aminobutanoic (acid)
1
(ii)     

1
(c)     (i)      C3H4O2
1
(ii)     

1
(1,4-)butan(e)dioic (acid)
(allow succinic, but not dibutanoic nor butanedicarboxylic acid)
1
(iii)     Can be hydrolysed / can react with acid or base or water /
can react with nucleophiles
1
[8]
 
5.   (a)     1, 4-diaminobutane or butane -1, 4-diamine (1)
A: BrCH2CH2Br or ClCH2CH2Cl (1)
B: NC CH2CH2CN
Step 1: Br2 or Cl2 (1) (ignore aq)
Step 2: KCN (1) (NOT HCN)
Step 3: H2 / Ni or LiAlH4 or Na / C2H5OH (1) (NOT NaBH4)
Hydrogenation only for H2 / Ni, or nucleophilic addition only for LiAlH4(1)
OR reduction or addition
7

(b)     
QL hydrogen bonding (1)
Polarity of H-bonding shown or discussed (1)
4
(c)     Polyamides / peptide link can be hydrolysed (1)
OR polyalkenes cannot be hydrolysed
          QL OH– attacks peptide link or Cd+ (1)
     poly(ethene) non-polar (1)
3
[14]

6.	D
[1]
7.	B
[1]
8.	B
[1]
9.	A
[1]
10.	C
[1]
11.	C
[1]