Cambridge International Examinations Cambridge International General Certificate of Secondary Education. Published

Size: px

Start display at page:

Download "Cambridge International Examinations Cambridge International General Certificate of Secondary Education. Published"

Alexandrina Morris
6 years ago
Views:

1 Cambridge International Examinations Cambridge International General Certificate of Secondary Education CHEMISTRY 060/4 Paper 4 Theory (Extended) May/June 06 MARK SCHEME Maximum Mark: 80 Published 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 May/June 06 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. This document consists of 9 printed pages. UCLES 06 [Turn over

2 Abbreviations used in the Mark Scheme Page Mark Scheme Syllabus Paper Cambridge IGCSE May/June ; separates marking points / separates alternatives within a marking point OR gives alternative marking point R reject I ignore mark as if this material was not present A accept (a less than ideal answer which should be marked correct) COND indicates mark is conditional on previous marking point owtte or words to that effect (accept other ways of expressing the same idea) max indicates the maximum number of marks that can be awarded ecf credit a correct statement that follows a previous wrong response ( ) the word / phrase in brackets is not required, but sets the context ora or reverse argument Cambridge International Examinations 06

3 Page Mark Scheme Syllabus Paper Cambridge IGCSE May/June (a) particle relative mass relative charge proton + neutron nil electron / 840 (b)(i) M atom(s) of the same element; M with different number of neutrons; (b)(ii) M (both have) the same number of electrons; M in the outer shell; (c) particle number of protons number of neutrons number of electrons 5 7 Li S K Cambridge International Examinations 06

4 Page 4 Mark Scheme Syllabus Paper Cambridge IGCSE May/June (a) number of moles of NaNO used:.40 / 85 = 0.04(00) (mol) OR 4.(00) 0 (mol); number of moles of O formed: 0.04 / = 0.0(00) (mol) OR.(00) 0 (mol); volume of O formed: = 0.48 (dm ); (b)(i) (a substance which is) a proton / H + / hydrogen ion acceptor; (b)(ii) (c) Mg(s) + H O(l) Mg(OH) (aq) + H (g) Mg(OH) ; rest of equation; M add a named acid, e.g. HCl and a named alkali, e.g. NaOH; M Al O will react with / neutralises both reagents; M and so it will dissolve into the reagent / form a solution; (d)(i) covalent; (d)(ii) (e)(i) any from: high melting point / high boiling point; poor conductor (of electricity); hard; insoluble; M (electrostatic) attraction; M between oppositely charged ions; (e)(ii) Ca (PO 4 ) ; Cambridge International Examinations 06

5 Page 5 Mark Scheme Syllabus Paper Cambridge IGCSE May/June (f)(i) M exothermic mark: horizontal product energy line at lower energy than that of reactant energy line; M label of product mark: SF 4 ; M correct direction of vertical heat of reaction arrow: arrow must start level with reactant energy and finish level with product energy and must have only one (correct) arrow-head; (f)(ii) M bond energy of F : F F = 60 = 0 (kj / mol); M bond energy of all bonds in SF 4 : = 00 (kj / mol); M calculated bond energy of SF 4 divided by 4: 00 / 4 = 75 (kj / mol); (g)(i) kills bacteria; (g)(ii) name of compound: cobalt(ii) chloride; from: blue; to: pink; (h)(i) it has a complete outer shell / a full outer shell / 8 electrons in the outer shell; (h)(ii) (in) lamps; Cambridge International Examinations 06

6 Page 6 Mark Scheme Syllabus Paper Cambridge IGCSE May/June (a) Na S O H O HCl OR HCl H O Na S O OR H O Na S O HCl OR H O HCl Na S O ; (b)(i) (b)(ii) (c) M volumes 40 : 0 : 0; M time = 4; M more particles per unit volume / particles are closer together; M increases the rate of collisions / there are more collisions per unit time; M particles gain more energy and move faster; M increasing rate of collisions / more collisions per unit time; M higher proportion of particles have sufficient energy to react / collisions have sufficient energy to react / are above the activation energy; Cambridge International Examinations 06

7 Page 7 Mark Scheme Syllabus Paper Cambridge IGCSE May/June (a)(i) reduction and (the Cu + ion / copper ions) is gaining electrons / is decreasing in oxidation number; 4(a)(ii) formation of Cu + / copper ions at the anode happens at the same rate as; removal of Cu + / copper ions at the cathode ora; 4(b) replace (anode of) copper with nickel; replace electrolyte with nickel(ii) sulfate / NiSO 4 ; 4(c) (good) catalysts; variable oxidation numbers; form coloured compounds / coloured ions; Cambridge International Examinations 06

8 Page 8 Mark Scheme Syllabus Paper Cambridge IGCSE May/June (a) (sulfur-containing) fossil fuels; 5(b) M vanadium pentoxide / vanadium(v) oxide / V O 5 (catalyst); M 5 atmospheres (units required); M 450 C (units required); M4 SO + O SO ; M5 equilibrium / reversible reaction; 5(c) H S O 7 ; 5 5(d)(i) correct ( marks) correct ( mark) bubbles / effervescence / fizzing; dissolves / disappears / forms a solution; blue (solution); 5(d)(ii) carbon dioxide and water and copper(ii) sulfate; 5(e)(i) carbon; 5(e)(ii) dehydration; Cambridge International Examinations 06

9 Page 9 Mark Scheme Syllabus Paper Cambridge IGCSE May/June (a) fractional distillation; cracking; 6(b)(i) addition; 6(b)(ii) CH ; 6(b)(iii) 6(c) M chain of 4 carbon atoms with single bonds and continuation bonds; M correctly positioned CH side chains; ; ; 6(d)(i) (concentrated) sulfuric acid; 6(d)(ii) methyl ethanoate; 6(d)(iii) M ester link; M rest of molecule; 6(d)(iv) terylene; Cambridge International Examinations 06

This document consists of 7 printed pages.

This document consists of 7 printed pages. Cambridge Assessment International Education Cambridge International General Certificate of Secondary Education CHEMISTRY 060/4 Paper 4 Extended Theory 017 MARK SCHEME Maximum Mark: 80 Published This mark