9701 w15 Ms 41 PDF
9701 w15 Ms 41 PDF
9701 w15 Ms 41 PDF
9701 CHEMISTRY
9701/41 Paper 4 (A2 Structured Questions), maximum raw mark 100
This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of
the examination. It shows the basis on which Examiners were instructed to award marks. It does not
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Cambridge is publishing the mark schemes for the October/November 2015 series for most
Cambridge IGCSE, Cambridge International A and AS Level components and some
Cambridge O Level components.
2259 kJ mol1
1 Ca(2+) is a smaller (ion) or Ca(2+) has a larger charge density 2
Ca(2+) has a stronger attraction / bond to H2O
12
1 0 1 2 3 2 1 0
(b) (i) SiCl4 white solid / ppt or misty / white / steamy fumes pH 03 3
PCl5 misty / white / steamy fumes pH 03
(ii) SiCl4 + 2H2O SiO2 + 4HCl 1
7
(ii) 2
species can act as a ligand cannot act as a ligand
NO3-
BF3
H2NCH2CH2NH2
NH4+
(c) (i) 5
formula of manganese type of reaction
species formed
Mn2+ (aq) + NaOH (aq) Mn(OH)2 precipitation
Mn(H2O)4(OH)2
Mn(OH)3
Mn2+ (aq) + concentrated HCl MnCl42 ligand exchange / substitution
MnCl64
Mn2+ (aq) + aqueous H2O2 Mn3+ redox / oxidation
H3C H3C
+
H3C
C Cl C OH + Cl
H3C
H3C H3C
-:
OH
(b) (i) time taken for the concentration of a reactant(s) to fall to half its original value 1
(ii) evidence of a pair of construction lines on graph and t = 4953 s 1
(iii) no effect / change 1
(c) (i) evidence of tangent at 80 s and data used, e.g. 0.42 / 152 = 0.00263 2
H3C
CH3
CH3
B B
N
10
SO3Na+ R Na+
SO3Na+ T
O3S S
(ii) Sn + HCl 3
NH2
CH3CH2
+ (nucleophilic)
NH2
CH3CH2Br substitution
O
Br-
12
Zn or Cu or Mg or Mn or Mo or Ni or Fe or Co (= enzyme co-factor)
(b) any three of: 3
M1: substrate binds to / fits into the active site of the enzyme
M2: Interaction with site causes a specific bond to be weakened, (which breaks)
(iii) oxidation 1
(d) (i) E = CH and F = CH2 1
(ii) E = triplet and adjacent 2H 2
F = doublet and adjacent 1H
11
10 (a) (i) 1
(iii) 3
OH
HO HO
NH2
NH2 O
O
CH3-OH