NATIONAL SENIOR ERTIFIATE NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD PYSIAL SIENES: EMISTRY (P) FISIESE WETENSKAPPE: EMIE (V) FEBRUARY/MAR 05/FEBRUARIE/MAART 05 MEMORANDUM MARKS/PUNTE: 50 This memorandum consists of 5 pages. ierdie memorandum bestaan uit 5 bladsye.
Physical Sciences P/Fisiese Wetenskappe V DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION /VRAAG. A (). D ().3 A ().4 D ().5 B ().6 ().7 B ().8 ().9 D ().0 B () [0]
Physical Sciences P/Fisiese Wetenskappe V 3 DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION /VRAAG.... arboxyl (group)/karboksiel(groep).. Ketones/Ketone..3 Addition/Addisie... Ethene/Eteen.. 4-methyl -hexan-3-one 4-metielheksan-3-oon 4-methyl-3-hexanone 4-metiel-3-heksanoon..3 4-ethyl-,-dimethylhexane 4-etiel-,-dimetielheksaan IF/INDIEN: orrect IUPA name, but one or more of the following errors: omitting hyphens and/or commas; including extra spaces and/or hyphens Korrekte IUPA-naam, maar een of meer van die volgende foute: weglating van koppeltekens en/of kommas; insluiting van ekstra spasies en/of koppeltekens Max./Maks. 4 methyl hexan 3 one 4 metiel 3 heksanoon () IF/INDIEN: orrect IUPA name, but one or more of the following errors: omitting hyphens and/or commas; including extra spaces and/or hyphens Korrekte IUPA-naam, maar een of meer van die volgende foute: weglating van koppeltekens en/of kommas; insluiting van ekstra spasies en/of koppeltekens Max./Maks. 4 ethyl, dimethylhexane 4 etiel, dimetielheksaan ().3 arbon dioxide/o /Koolstofdioksied Water/ O ()
Physical Sciences P/Fisiese Wetenskappe V 4 DBE/Feb. Mar. 05/Feb. Mrt. 05.4.4. O ondensed or semi-structural formula: Gekondenseerde of semistruktuurformule: Molecular formula/molekulêre formule: O 0 Notes/Aantekeninge Whole structure correct/ele struktuur korrek: Only functional group correct/slegs funksionele groep korrek: ().4. ANY ONE/ENIGE EEN: Two marks or zero./twee punte of nul. ondensed or semi-structural formula: Max. Gekondenseerde of semistruktuurformule: Maks. Molecular formula/molekulêre formule: 0 ().5.5. E.5. Substitution/halogenation/bromination Substitusie/halogenering/brominering.5.3 Notes/Aantekeninge Br Br Whole structure correct/ele struktuur korrek: Only functional group correct/slegs funksionele groep korrek: ondensed or semi-structural formula: Gekondenseerde of semistruktuurformule: Molecular formula/molekulêre formule: 0 () [8]
Physical Sciences P/Fisiese Wetenskappe V 5 DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION 3/VRAAG 3 3. 3. 3.. hain length/molecular size/molecular mass/number of carbon atoms in the chain. Kettinglengte/molekulêre grootte/molekulêre massa/aantal koolstof-atome in die ketting. 3.. Boiling point Kookpunt 3.3 London (forces)/induced dipole (forces)/dispersion (forces) London (kragte)/geïnduseerde dipool (kragte)/dispersie (kragte) 3.4 igher than oër as 3.5 Lower than/laer as Both compounds D and E have hydrogen bonding between molecules. Beide verbindings D en E het waterstofbinding tussen molekule. ompound D has one site for hydrogen bonding whilst compound E has two sites for hydrogen bonding/forms dimers OR ompound D has less sites for hydrogen bonding/weaker hydrogen bonding than compound E. Verbinding D het een punt vir waterstofbinding terwyl verbinding E twee punte het vir waterstofbinding./vorm dimere OF Verbinding D het minder punte vir waterstofbinding/swakker waterstofbinding as verbinding E. More energy needed to overcome intermolecular forces in compound E/less energy needed to overcome intermolecular forces in compound D. Meer energie nodig om die intermolekulêre kragte te oorkom in verbinding E/minder energie nodig om die intermolekulêre kragte in verbinding E te oorkom. (4) [9]
Physical Sciences P/Fisiese Wetenskappe V 6 DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION 4/VRAAG 4 4. Unsaturated Onversadig ontains a double bond/multiple bond (between atoms). Bevat 'n dubbelbinding/meervoudige binding (tussen -atome). () 4.. O Notes/Aantekeninge Whole structure correct /ele struktuur korrek: Only functional group correct/slegs funksionele groep korrek: () 4.. Addition/hydration Addisie/hidrasie 4.3 4.3. -chlorobutane -chlorobutaan IF/INDIEN: orrect IUPA name, but one or more of the following errors: omitting hyphens and/or commas; including extra spaces and/or hyphens Korrekte IUPA-naam, maar een of meer van die volgende foute: weglating van koppeltekens en/of kommas; insluiting van ekstra spasies en/of koppeltekens Max./Maks. () 4.3. Notes/Aantekeninge Whole structure correct/ele struktuur korrek: l Only functional group correct/slegs funksionele groep korrek: ()
Physical Sciences P/Fisiese Wetenskappe V 7 DBE/Feb. Mar. 05/Feb. Mrt. 05 4.4 4.4. NO POSITIVE MARKING FROM QUESTION 4.3.. GEEN POSITIEWE NASIEN VANAF VRAAG 4.3.. O OR dilute NaO/KO O OF verdunde NaO/KO Mild heat/matige hitte () 4.4. Substitution/hydrolysis Substitusie/hidrolise 4.4.3 4 9 l + NaO 4 0 O + Nal bal. 4 9 l + O 4 0 O + l bal. Notes/Aantekeninge Reactants Products Balancing Reaktanse Produkte Balansering Do not penalise if 4 9 O instead of 4 0 O./Moenie penaliseer indien 4 9 O in plaas van 4 0 O Ignore/Ignoreer Marking rule 6.3.0/Nasienreël 6.3.0 ondensed structural formulae or structural formulae: Gekondenseerde struktuurformules of struktuurformules: Max./Maks. 3 (3) [5] QUESTION 5/VRAAG 5 5. Exothermic/Eksotermies Temperature increases during reaction./t i T f Temperatuur verhoog tydens die reaksie./t i T f () 5. Larger surface area in experiment. Groter reaksieoppervlakte in eksperiment. Smaller surface area in experiment. Kleiner reaksieoppervlakte in eksperiment. 5.3 More than one independent variable. Meer as een onafhanklike veranderlike. Different concentrations and state of division. Verskillende konsentrasies en toestand van verdeeldheid.
Physical Sciences P/Fisiese Wetenskappe V 8 DBE/Feb. Mar. 05/Feb. Mrt. 05 5.4 Faster than Vinniger as A catalyst was used in experiment 5. 'n Katalisator is gebruik in eksperiment 5. A catalyst provides an alternative pathway of lower activation energy. 'n Katalisator voorsien 'n alternatiewe pad van laer aktiveringsenergie. More molecules have sufficient/enough kinetic energy. Meer molekule het voldoende/genoeg kinetiese energie. More molecules have kinetic energy equal to or greater than the activation energy. Meer molekule het kinetiese energie gelyk aan of groter as die aktiveringsenergie. More effective collisions per unit time./rate or frequency of effective collisions increases. Meer effektiewe botsings per eenheidstyd./tempo of frekwensie van effektiewe botsings neem toe. (5) 5.5 Marking criteria/nasienriglyne: n Formula/Formule: n = M Substitute/Vervang 65 Use ratio/gebruik verhouding : Substitute mole acid in rate equation/vervang mol suur in tempovergelyking Substitute time in rate equation/vervang tyd in tempovergelyking Final answer/finale antwoord: 0,00465 0,00463 mol s - n n(zn) = M, = 65 = 0,08 mol n(l reacted/gereageer) = (0,08) = 0,037 mol Δ n rate/tempo = Δ t 0,037-0,037 = = 8 8 = 4,63 x 0-3 mol s - - 4,63 x 0-3 mol s - Accept range/aanvaar gebied: 0,00465 0,00463 mol s - (6) [5]
Physical Sciences P/Fisiese Wetenskappe V 9 DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION 6/VRAAG 6 6. A reaction is reversible when products can be converted back to reactants. 'n Reaksie is omkeerbaar wanneer die produkte terug verander kan word na reaktanse. 6. No change Geen verandering 6.3 6.3. Temperature decreases Temperatuur verlaag Accept/Aanvaar: Temperature changes Temperatuur verander 6.3. Decrease in temperature decreases the rate of both forward and reverse reactions. Verlaging in temperatuur verlaag die tempo van beide die voorwaartse en terugwaartse reaksies. Decrease in temperature favours the exothermic reaction. Verlaging in temperatuur bevoordeel die eksotermiese reaksie. The rate of the reverse (exothermic) reaction is faster or the reverse reaction is favoured./the rate of the forward (endothermic) reaction is slower. Die tempo van die terugwaartse (eksotermiese) reaksie is vinniger of die terugwaartse reaksie word bevoordeel./die tempo van die voorwaartse (endotermiese) reaksie is stadiger. (3) 6.4 Mark criteria/nasienriglyne: orrect K c expression (formulae in square brackets). Korrekte K c uitdrukking (formules in vierkanthakies). Divide equilibrium moles by dm 3. Deel aantal mol by ewewig deur dm 3. At equilibrium: [ ] = [I ] = x/by ewewig: [ ] = [I ] Substitution of concentrations into K c expression. Vervanging van konsentrasies in K c -uitdrukking. Substitution of K c value. Vervanging van K c -waarde. Final answer/finale antwoord:,83 x 0-3 mol dm -3
Physical Sciences P/Fisiese Wetenskappe V 0 DBE/Feb. Mar. 05/Feb. Mrt. 05 OPTION /OPSIE At equilibrium/by ewewig: [ ] = [I ] [ ] [ I] K c = [I] 0,0 = (x) ( x) 0,04 Divide by dm 3 Deel deur dm 3 x = [ ] =,83 x 0-3 mol dm -3 (0,008 mol dm -3 ) No K c expression, correct substitution: Geen K c -uitdrukking, korrekte substitusie: Wrong K c expression/verkeerde K c -uitdrukking: Max./Maks. Max./Maks. 5 6 6 OPTION /OPSIE Initial quantity (mol) Aanvangshoeveelheid (mol) hange (mol) Verandering (mol) Quantity at equilibrium (mol)/ oeveelheid by ewewig (mol) Equilibrium concentration (mol dm -3 ) Ewewigskonsentrasie (mol dm -3 ) I I x 0 0 x - 0,04 0,04 0,0 x 0,04 x 0,04 x 0,04 4 x 0,04 x 0,04 x 0,04 4 ratio verhouding Divide by dm 3 Deel deur dm 3 [ ] [ I] K c = [I] x 0,04 x 0,04 ( )( ) 0,0 = 4 4 (0,0) x = 0,05 No K expression, correct substitution/geen K c - uitdrukking, korrekte substitusie: Max./Maks. 5 6 Wrong K expression/verkeerde K c -uitdrukking: Max./Maks. 6 x 0,04 [ ] = 0,05 0,04 = =,83 x 0-3 mol dm -3 (6) 6.5 K c = 0,0 = 50 6.6 Increases Vermeerder [4]
Physical Sciences P/Fisiese Wetenskappe V DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION 7/VRAAG 7 7. 7.. An acid is a proton ( + ion) donor. 'n Suur is 'n proton ( + ioon) -donor/-skenker. () 7.. It ionises to form protons/ moles of + ions. Dit ioniseer om protone/ mol + -ione te vorm. It donates + ions per SO 4 molecule. Dit skenk + ione per SO 4 -molekuul. 7. 7.. Amphiprotic (substance)/ampholyte Amfiprotiese (stof)/amfoliet 7.. O 3 (aq) 7.3 7.3. m n(nao3 ) = M 7 = 84 = 0,3 mol (0,03485 mol) n( SO 4 ) = ½n(NaO 3 ) = ½(0,3) = 0,6 mol (0,06074 mol) n c = V 0,6 6 = V 3 V = 0,03 dm (30 cm 3 /0,07 dm 3 /7 cm 3 ) (6) 7.3. n a (initial/aanvanklik) = n a (final/finaal) c a v a (initial/aanvanklik) = c a v a (final/finaal) (6)v a = (0,) v a = 0,0 dm 3 (0 cm 3 /0,067 dm 3 /6,7 cm 3 ) () 7.3.3 Shows end point (of titration)./shows when neutralisation occurs. Toon die eindpunt (van titrasie) aan./toon aan wanneer neutralisasie plaasvind.
Physical Sciences P/Fisiese Wetenskappe V DBE/Feb. Mar. 05/Feb. Mrt. 05 7.3.4 Marking criteria/nasienriglyne: Substitute initial [acid] and volume/vervang aanvanklike [suur] en volume Substitute initial [base] and volume/vervang aanvanklike [basis] en volume Use ratio/gebruik verhouding : Initial mole acid mole acid reacted/aanvanklike mol suur mol suur gereageer Substitute volume acid + volume base/vervang volume suur + volume basis p formula/p-formule Substitute x c a in p formula/vervang x c a in p-formule Final answer/finale antwoord:,44 n a (initial/aanvanklik) = c a v a = (0,)(5 x 0-3 ) =,5 x 0-3 mol n b (reacted/gereageer) = c b v b = (0,)(30 x 0-3 ) = 3 x 0-3 mol n a = nb n a (neutralised/geneutraliseer) = ½n b = ½(3 x 0-3 ) =,5 x 0-3 mol n a (left/oorgebly) = n a (initial/aanvanklik) - n a (neutralised/geneutraliseer) =,5 x 0-3 -,5 x 0-3 = x 0-3 mol n c a = V 3 0 = 3 3 (5 0 + 30 0 ) = 0,08 mol dm 3 p = -log[ 3 O + ] = -log( x 0,08) =,44 (8) []
Physical Sciences P/Fisiese Wetenskappe V 3 DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION 8/VRAAG 8 8. A substance that is being reduced. 'n Stof wat gereduseer word. A substance that gains/accepts electrons. 'n Stof wat elektrone wen/bykry. A substance whose oxidation number decreases. 'n Stof waarvan die oksidasiegetal afneem. () 8. Ag + is a stronger oxidising agent than u + and will oxidise u to (blue) u + ions. Ag + is 'n sterker oksideermiddel as u + en sal u oksideer na (blou) u + - ione. u + is a weaker oxidising agent than Ag + and u will be oxidised to u + ions u + is 'n swakker oksideermiddel as Ag + en sal geoksideer word tot u + - ione. 8.3 hemical Electrical hemies Elektries (4) 8.4 A 8.5 Option /Opsie θ θ θ E E E cell = reduction oxidation = +0,80 0,34 = +0,46 V Notes/Aantekeninge Accept any other correct formula from the data sheet. Aanvaar enige ander korrekte formule vanaf gegewensblad. Option /Opsie u u + + e - Ag + + e - Ag E = - 0,34 E = +0,80 E = 0,46 V Any other formula using unconventional θ θ θ abbreviations, e.g. Ecell = EOA ERA followed by correct substitutions: 3 4 Enige ander formule wat onkonvensionele θ θ θ afkortings gebruik bv. Esel = EOM ERM gevolg deur korrekte vervangings : 3 4 (4) 8.6 u + Ag + (aq) u + (aq) + Ag(s) Balancing Notes/Aantekeninge Reactants Products Balancing Reaktanse Produkte Balansering Ignore/Ignoreer Ignore phases. Marking rule 6.3.0/Nasienreël 6.3.0. (3) 8.7 Remains the same Bly dieselfde [6]
Physical Sciences P/Fisiese Wetenskappe V 4 DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION 9/VRAAG 9 9. A solution that conducts electricity (through the movement of ions). 'n Oplossing wat elektrisiteit gelei (deur die beweging van ione). A substance that conducts electricity through the movement of ions. 'n Stof wat elektrisiteit gelei deur die beweging van ione. A solution/melt that consists of ions. 'n Oplossing/gesmelte stof wat ione bevat. () 9. 9.. O + e - + O - O + e - + O - + O - O + e - 0 + O - O + e - 0 + O - O + e - () 9.. hlorine gas/l hloorgas/l 9.3 O is a stronger oxidising agent (than Na + ) and will be reduced (to ). O is 'n sterker oksideermiddel (as Na + ) en sal gereduseer word (na ). The half-reaction that produces (g) has a more positive reduction potential (-0,83 V) than the half-reaction that produces Na (-,7 V). Die halfreaksie wat (g) vorm, het 'n meer positiewe reduksie potensiaal (-0,83 V) as die halfreaksie wat Na vorm (-,7 V). Therefore water/ O will be reduced to./na + will not be reduced to Na. Daarom word water/ O na gereduseer./na + sal nie gereduseer word na Na nie. () [7]
Physical Sciences P/Fisiese Wetenskappe V 5 DBE/Feb. Mar. 05/Feb. Mrt. 05 QUESTION 0/VRAAG 0 0. ontact process/kontakproses 0. 0.. Vanadium pentoxide/vanadium(v) oxide/v O 5 Vanadiumpentoksied/Vanadium(V) oksied/v O 5 0.. S O 7 (l) + O(l) SO 4 (l) Bal Reactants Products Balancing Reaktanse Produkte Balansering Ignore/Ignoreer Marking rule 6.3.0/Nasienreël 6.3.0 (3) 0.3 0.3. SO 4 + N 3 (N 4 ) SO 4 Bal Reactants Products Balancing Reaktanse Produkte Balansering Ignore/Ignoreer Marking rule 6.3.0/Nasienreël 6.3.0 (3) 0.3. Ammonium sulphate Ammoniumsulfaat 0.4 0.4. Total percentage of fertiliser. Totale persentasie kunsmis. 0.4. 5 Mass of fertiliser in P/Massa kunsmis in P: x 50 =,5 kg 00 0 Mass of fertiliser in Q/Massa kunsmis in Q: x 50 = 0 kg 00 Amount of potassium in P/Massa kalium in P: 0 3 x,5 = 3,75 kg Amount of potassium in Q/Massa kalium in Q: 8 4 x 0 = 5 kg Fertiliser Q has more potassium per mass than fertiliser P. Kunsmis Q het meer kalium per massa as kunsmis P. (4) [4] TOTAL/TOTAAL: 50