MARK SCHEME for the October/November 2015 series 9701 CHEMISTRY

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1 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9701 CHEMISTRY 9701/22 Paper 2 (AS Structured Questions), maximum raw mark 60 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 indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. 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. IGCSE is the registered trademark of Cambridge International Examinations.

2 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November Question Mark Scheme Mark Total 1 (a) name of isotope type of particle charge symbol electron configuration 13 carbon-13 atom 0 6 C 1s 2 2s 2 2p 2 chloride(-37) anion 1 Cl 1s 2 2s 2 2p 6 3s 2 3p 6 [5] [5] 34 sulfur-34 atom 0 16 S 1s 2 2s 2 2p 6 3s 2 3p 4 iron-54 cation (2 ) 26 Fe + 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 (b) (i) ability / tendency / power of an atom / nucleus to attract / pull electron(s) in a covalent bond / shared pair of electrons / bonding pair of electrons Covalent overlap of orbitals shared pair(s) (of electrons) metallic positive ions / cations surrounded by delocalised electrons Ionic/electrovalent (electrostatic) Attraction between oppositely charged / +ve and ve ions (c) (i) similar strength / amount / number of intermolecular forces / induced dipole / van der Waals / VdW / London forces / LDF / dispersion forces therefore similar energy needed Cambridge International Examinations 2015

3 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November Question Mark Scheme Mark Total M1 HCl polar / has a dipole AND F 2 non-polar / has no dipole (permanent) dipole (-dipole) attractions / forces between HCl (molecules) AND induced dipole (-induced dipole) attractions / forces / LDFs between F 2 (molecules) M2 more energy needed for HCl than F 2 pd-pd forces stronger than id-id forces IMFs / VdWs in HCl stronger than in F 2 Hydrogen bonding (between methanol molecules) Stronger than IMFs / van der Waals in other three / is the strongest intermolecular force [17] 2 (a) M1 Heat (energy) change (or H prod H react ) measured at constant pressure enthalpy change when the amount/moles of reactants as shown in a (reaction) equation react together to give products M2 measured at standard conditions (b) (i) q = amount = 0.025(0) 85.(0) Cambridge International Examinations 2015

4 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November Question Mark Scheme Mark Total (iv) ( MgSO 4 (s) + 7H 2 O(l) MgSO 4.7H 2 O(s) ) 85.0 (kj mol 1 ) (+)9.60 (kj mol 1 ) MgSO 4 (aq) (v) H = 85.0 H = = 94.6 (kj mol 1 ) 3 (a) (i) Na 2 O or Na 2 O 2 ; MgO; P 4 O 10 or P 4 O 6 ; SO 2 [7] Na: Yellow / orange / gold flame / white solid / powder / smoke 4Na + O 2 2Na 2 O or 2Na + O 2 Na 2 O 2 S: Blue flame / (yellow) solid melts / turns red / amber / white fumes S + O 2 SO 2 [4] (b) (i) acidic P and S amphoteric Al and basic Na and Mg acidic: covalent (bonding) basic: ionic (bonding) Cambridge International Examinations 2015

5 Page 5 Mark Schemee Cambridge International AS/ /A Level October/November 2015 Syllabus Paper 222 Question Markk Scheme Mark Total + 6HC6 Cl 2AlCl + 6H 6 + 2Al H 2 O + 3H 2 2O 2NaOH + 7HH 2 O 2NaOH + 3HH 2 O 2NaAl (OH) 4 (H 2 O) O 2 2NaAl (OH) 4 R 2NaOH 2NaAlO2 + H 2 O R 2OH 2OH 2OH + 7H7 2 O 2[Al( 2 (OH) 4 (HH 2 O) 2 ] + 3H3 2 O 2[Al( 2 (OH) 4 ] 2AlO2 O 2 + H 2 O R (c) sulfurr formss SOO 2 / SO 2 + / mixem es H 2 O H 2 SOS 3 or in wordss SOO 2 + / mixesm s H 2 2O ( a( acid) / or in words SOO 2 + / mixesm s H 2 2O + (1/2O2) H 2 SO4 / or r in words [14] 4 (a) (i) Nucleophilic Substitution Has a chiral centre / carbon R has a carbon / C attached to 4 different groups / atoms / chainss has no planee / line of o symmetryy [1+ +1] (iv) Elimination Cambridgee International ExamE minations 2015

6 Page 6 Mark Schemee Cambridge International AS/ /A Level October/November 2015 Syllabus Paper 222 Question Markk Scheme Mark Total (v) (vi) But-1-ene 2 Hs on one o of the double-bondedd groups on bothb h atomss / each atomm inn C= Css does not have 2 different =C (b) (i) ammoniaa / N H 3 propanoyl chloride / C 2 H 5 COCl CH 3 CH(NHCOCC 2 H5)CH 5 H 3 (iv) Reduction LiAlHH 4 / lithium aluminium hydride / lithiumm tetrahydridoaluminate (1) (v) aluminiumm oxide Cambridgee International ExamE minations 2015

7 Page 7 Mark Schemee Cambridge International AS/ /A Level October/November 2015 Syllabus Paper 222 Question Markk Scheme Mark Total (vi) [4] M1 = correctt structure of Y and curly arrow fromm double bond to H M2 = dipole and curly arrow from H-Br bond to Br M3 = correctt intermediate M4 = Br with lone pairr and curly arrow from lone pair to C(+) C ) (vii) electrophilic addition (viii) secondary carbocation more stabs ble than primary due too electron releasing character /(pos( sitive) inductive effect of alkya yl groups [22] Cambridgee International ExamE minations 2015

MARK SCHEME for the October/November 2015 series 9701 CHEMISTRY. 9701/11 Paper 1 (Multiple Choice), maximum raw mark 40

CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 205 series 970 CHEMISTRY 970/ Paper (Multiple Choice), maximum raw