Physical Sciences Grade 12 Paper 2 NSC November 2022 Memo

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 12 PHYSICAL SCIENCES: CHEMISTRY (P2) FISIESE WETENSKAPPE: CHEMIE (V2) NOVEMBER 2022 MARKING GUIDELINES/NASIENRIGLYNE MARKS/PUNTE: 150 These marking guidelines consist of 19 pages. Hierdie nasienriglyne bestaan uit 19 bladsye. Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 2 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne QUESTION 1/VRAAG 1 1.1 B  (2) 1.2 D  (2) 1.3 C  (2) 1.4 C  (2) 1.5 A  (2) 1.6 C  (2) 1.7 D  (2) 1.8 D  (2) 1.9 A  (2) 1.10 A  (2) [20] QUESTION 2/VRAAG 2 2.1 2.1.1 C&D (1) 2.1.2 Functional/Funksionele  (1) 2.1.3 CnH2n-2  (1) 2.1.4 Hydroxyl (group)/Hidroksiel(groep)  (1) 2.2 2.2.1 4-bromo-3,3-dimethylhexane/4-bromo-3,3-dimetielheksaan  Marking criteria:  Correct stem i.e. hexane.   All substituents (bromo and dimethyl) correctly identified.   IUPAC name completely correct including numbering, sequence, hyphens and commas.  Nasienkriteria:  Korrekte stam d.i. heksaan.   Alle substituente (bromo en dimetiel) korrek geïdentifiseer.   IUPAC-naam heeltemal korrek insluitende nommering, volgorde, koppeltekens en kommas.  (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 3 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 2.2.2 4,4-dimethylpent-2-yne/4,4-dimethyl-2-pentyne  4,4-dimetielpent-2-yn/4,4-dimetiel-2-pentyn Marking criteria/Nasienkriteria:  Correct stem and substituents: dimethyl and pentyne  Korrekte stam en substituente: dimetiel en pentyn  IUPAC name completely correct including numbering, sequence, hyphens and commas.  IUPAC-naam heeltemal korrek insluitende nommering, volgorde, koppeltekens en kommas. (2) 2.2.3 Butanal/Butanaal  Marking criteria/Nasienkriteria:  Correct functional group: -al / Korrekte funksionele groep: –aal   IUPAC name correct/IUPAC-naam korrek  (2) 2.3 2.3.1 Esterification/condensation  Esterfikasie/verestering/kondensasie (1) 2.3.2 M(C3H6O) = 58 g·mol-1 Marking criteria/Nasienkriteria:  C6H12O2   C2H4O2  ii  If only correct answer given  Indien slegs korrekte antwoord gegee = =2 Compound S = C6H12O2  C2H4O2  NOTE/LET WEL  Condensed or structural formula/Gekondenseerde of struktuurformule: Max./Maks. ⁄ (3) [15] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 4 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne QUESTION 3/VRAAG 3 3.1.1 Ketone/Ketoon  (1) 3.1.2 Functional group/homologous series  Funksionele groep/homoloë reeks (1) 3.1.3 Marking criteria:  Compare structures.   Compare the strength of intermolecular forces.   Compare the energy required to overcome intermolecular forces.   State the difference in melting point.  Nasienkriteria:  Vergelyk strukture.   Vergelyk die sterkte van intermolekulêre kragte.   Vergelyk die energie benodig om intermolekulêre kragte te oorkom.   Noem die verskil in smeltpunte.  Pentan-2-one/C  Structure: Longer chain length/less branched/less compact/less spherical/larger surface area (over which intermolecular forces act).   Intermolecular forces: Stronger/more intermolecular forces/Van der Waals forces/London forces/ dipole-dipole forces.   Energy: More energy needed to overcome or break intermolecular forces/Van der Waals forces/dipole-dipole forces.   Higher melting point.  NOTE IF higher boiling point - Max. ⁄ OR 3-methylbutanone/D  Structure: Shorter chain length/more branched/more compact more spherical/smaller surface area (over which intermolecular forces act).   Intermolecular forces: Weaker/less intermolecular forces/Van der Waals forces/London forces/ dipole-dipole forces.   Energy: Less energy needed to overcome or break intermolecular forces/Van der Waals force/dipole-dipole forces.   Lower melting point. NOTE IF lower boiling point - Max. ⁄ Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 5 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne Pentan-2-oon/C  Struktuur: Langer kettinglengte/minder vertak/minder kompak/minder sferies/groter oppervlak (waaroor intermolekulêre kragte werk).   Intermolekulêre kragte: Sterker/meer intermolekulêre kragte/Van der Waalskragte/Londonkragte/ dipool-dipoolkragte.   Meer energie benodig om intermolekulêre kragte/Van der Waalskragte/ Londonkragte/dipool-dipoolkragte te oorkom/breek.   Hoër smeltpunt.  LET WEL INDIEN hoër kookpunt - Maks. ⁄ OF 3-metielbutanoon/D  Struktuur: Korter kettinglengte/meer vertak/meer kompak/meer sferies/kleiner oppervlak (waaroor intermolekulêre kragte werk).   Intermolekulêre kragte: Swakker/minder intermolekulêre kragte/Van der Waalskragte/ Londonkragte/dipool-dipoolkragte.   Energie: Minder energie benodig om intermolekulêre kragte/Van der Waalskragte/ Londonkragte/dipool-dipoolkragte te oorkom/breek.   Laer smeltpunt.  LET WEL INDIEN laer kookpunt - Maks. ⁄ (4) 3.2.1 Marking criteria/Nasienkriteria If any one of the underlined key words phrases in the correct context (vapour pressure) is omitted, deduct 1 mark./Indien enige van die onderstreepte sleutelwoorde of frases in die korrekte konteks (dampdruk) uitgelaat is, trek 1 punt af. The pressure exerted by a vapour at equilibrium with its liquid in a closed system.  Die druk uitgeoefen deur 'n damp in ewewig met sy vloeistof in 'n geslote sisteem. (2) 3.2.2 Marking criteria/Nasienkriteria:  Dependent and independent variables correctly identified.  Afhanklike en onafhanklike veranderlikes korrek geïdentifiseer.  Correct relationship between dependent and independent variables stated.  Korrekte verwantskap tussen die afhanklike en onafhanklike veranderlikes gestel. Vapour pressure decreases with increase in number of C atoms/chain length.  Dampdruk neem af met toename in aantal C-atome/kettinglengte. OR/OF Vapour pressure increases with decrease in number of C atoms/chain length. Dampdruk neem toe met afname in aantal C-atome/kettinglengte. (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 6 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 3.2.3 Hexan-1-ol/1-Hexanol Marking criteria/Nasienkriteria   Correct chain length i.e. hex  Heksan-1-ol/1-Heksanol Korrekte kettinglengte d.i. heks  IF hexanol/INDIEN heksanol Max/Maks: ⁄  Whole name correct./Volledige naam korrek. ⁄ (3) 3.2.4 Increases/Toeneem  (1) [14] QUESTION 4/VRAAG 4 4.1 Tertiary/Tersiêre  The halogen/bromine/functional group (-X) is bonded to a C atom that is bonded to three other C atoms/ a tertiary C atom.  Die halogeen/broom/funksionele groep (-X) is gebind aan 'n C-atoom wat aan drie ander C-atome gebind is/ 'n tersiêre C-atoom. OR/OF The functional group ( C ) is bonded to three other C atoms. X/Br Die funksionele groep ( C ) is gebind aan drie ander C-atome. X/Br (2) 4.2.1 Concentrated strong base  OR Concentrated NaOH/KOH/LiOH/sodium hydroxide/ potassium hydroxide/ lithium hydroxide OR Strong base/NaOH/KOH/LiOH/sodium hydroxide/ potassium hydroxide/lithium hydroxide in ethanol. Gekonsentreerde sterk basis OF Gekonsentreerde NaOH /KOH/ LiOH /natriumhidroksied/ kaliumhidroksied/ litiumhidroksied OF Sterk basis/NaOH /KOH/ LiOH / natriumhidroksied/kaliumhidroksied/litium- hidroksied in etanol (1) 4.2.2 Elimination/dehydrohalogenation/dehydrobromination  Eliminasie/dehidrohalogenering/dehidrohalogenasie/dehidrobrominasie/ dehidrobromonering (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 7 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 4.2.3 Marking criteria:  Whole structural formula correct for compound A.   React (2-bromo-2-methylbutane) with NaOH/KOH/LiOH.   Functional group of alkene correct.   Whole structural formula of alkene correct.   NaBr/KBr/LiBr + H2O  Nasienkriteria:  Hele struktuurformule vir verbinding A korrek.   Reageer (2-bromo-2-metielbutaan) met NaOH/KOH/LiOH.   Funksionele groep van alkeen korrek.   Hele struktuurformule van alkeen korrek.   NaBr/KBr/LiBr + H2O  IF/INDIEN  Any error e.g. omission of H atoms, condensed or semi structural formula/Enige fout bv. weglating van H-atome, gekondenseerde of semi-struktuurformule: Max/Maks. ⁄  Any additional reactants or products /Enige addisionele reaktanse of produkte: Max./Maks. ⁄  Molecular formulae used:/Molekulêre formule gebruik: Max./Maks. ⁄  No or incorrect inorganic reactants or products:/ Geen of verkeerde anorganiese reaktanse of produkte: Max./Maks. ⁄  Marking rule 6.3.10/Nasienreël 6.3.10 H H C H H H H   H C C C C H + NaOH/ KOH/LiOH H Br H H H H C H  H H H   H C C C C H + NaBr/ KBr/LiBr + H2O H H (5) 4.3.1 H Marking criteria/Nasienkriteria:  Functional group correct  H C H Funksionele groep korrek H H  Whole structure correct  H  Hele struktuur korrek H C C C C H H O H H  H (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 8 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 4.3.2 Water/H2O  (1) 4.3.3 Hydration/Hidrasie  (1) 4.4.1 Substitution/Hydrolysis/Substitusie/Hidrolise  (1) 4.4.2 Dilute strong base  OR: Dilute NaOH/KOH/LiOH/sodium hydroxide/potassium hydroxide/lithium hydroxide OR: NaOH(aq)/KOH(aq)/LiOH(aq) OR: (Add) water/H2O Verdunde sterk basis OF: Verdunde NaOH/KOH/LiOH/natriumhidroksied/ kaliumhidroksied/ litiumhidroksied OF: NaOH(aq)/KOH(aq)/LiOH(aq) OF: (Voeg) water/H2O (by) (1) [15] QUESTION 5/VRAAG 5 5.1 B  The catalyst provides an alternative route of lower activation energy.   More molecules have enough/sufficient (kinetic) energy./More molecules have (kinetic) energy equal to or higher than the activation energy.   More effective collisions per unit time./Higher frequency of effective collisions.   Die katalisator verskaf 'n alternatiewe roete van laer aktiveringsenergie.  Meer molekule het genoeg/voldoende (kinetiese) energie./Meer molekule het (kinetiese) energie gelyk aan of groter hoër as die aktiveringsenergie.  Meer effektiewe botsings per eenheidtyd./Hoër frekwensie van effektiewe botsings. (4) 5.2 Y  (2) 5.3 5.3.1 560 (cm3) / 0,56 dm3  (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 9 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 5.3.2 POSITIVE MARKING FROM QUESTION 5.3.1. POSITIEWE NASIEN VANAF VRAAG 5.3.1. Marking criteria: Nasienkriteria: (a) Substitute 24 000 and 560/24 and 0,56 (a) Vervang 24 000 en 560/24 en 0,56 in n =  in n =  m (b) USE mol ratio: (b) GEBRUIK molverhouding: n(H2O) : n(O2) = 2 : 1  n(H2O) : n(O2) = 2 : 1  (c) Substitute 18 and n(H2O) in (c) Vervang 18 en n(H2O) in m = nM  m = nM  (d) Final answer: 0,83 g  (d) Finale antwoord: 0,83 g  Range: 0,72 to 0,9 g Gebied: 0,72 tot 0,9 g OPTION 1/OPSIE 1 OPTION 2/OPSIE 2 3 ……. n(O2) = 3 (a) x ……. x = 0,023 mol (0,0233) = (a) = 0,023 mol (0,0233) n(H2O) = 2n(O2) n(H2O) = 2(0,023) (b) n(H2O) = 2n(O2) = 0,046 mol (0,0467) n(H2O) = 2(0,023) (b) = 0,046 mol (0,0467) m = nM (c) = 0,0466 x 18 m = nM = 0,83 g (d) (c) = 0,046 x 18 = 0,83 g (d) (4) 5.4 5.4.1 0 (g∙ -1) / zero / nul  (1) 5.4.2 Greater than/Groter as  (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 10 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 5.4.3 Marking criteria Nasienkriteria: m a) Substitute 0,9 g in  a) Vervang 0,9 g in  m b) Substitute 32 in  b) Vervang 32 in  c) USE mol /rate ratio: c) GEBRUIK mol-/tempoverhouding: n(H2O2) : n(O2) = 2 : 1  n(H2O2) : n(O2) = 2 : 1  d) Substitute 2,1 x 10-3 and n(H2O2) in d) Vervang 2,1 x 10-3 en n(H2O2) in rate formula  tempoformule  OR: Substitute rate O2 (1,05 x 10-3) OF: Vervang tempo O2 (1,05 x 10-3) and n(O2) in rate formula en n(O2) in tempoformule OR: Substitute rate O2 (0,0336 g·s-1) OF: Vervang tempo O2 (0,0336 g·s-1) in rate formula in tempoformule e) Final correct answer: 26,67 (s)  e) Finale korrekte antwoord: 26,67 (s)  Range: 26,67 to 28,57 (s) Gebied: 26,67 tot 28,57 (s) OPTION 1/OPSIE 1 OPTION 2/OPSIE 2 ………………. g (b) n(O2) = x ………………. g (a) (a) x = 0,0275 mol = (b) n(H2O2) = 2n(O2) = 0,028 mol (0,0281) = 2(0,0275) (c) = 0,056 mol n(H2O2) = 2n(O2) = 2(0,028)(c) rate/tempo = = 0,056 = (d) - rate/tempo = 2,1 x 10-3 = (d) = 26,67 (s) (e) - 2,1 x 10-3 = = 26,67 (s) (e) OPTION 3/OPSIE 3 OPTION 4/OPSIE 4 rate H2O2 = 2,1 x 10-3 mol·s-1 n(O2) = (a) Rate(O2) = ½ rate(H2O2) = = ½ (2,1 x 10-3) (c) (b) = 1,05 x 10-3 = 0,028 mol (0,0281) In one second: Rate(O2) = ½ rate(H2O2) ( ) = ½ (2,1 x 10-3) (c) = 1,05 x 10-3 x (b) ( ) g rate/tempo = g∙ (d) 1,05 x 10-3 = (a) (d) = 26,67 (s) (e) ( (e) (5) [19] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 11 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne QUESTION 6/VRAAG 6 6.1 Marking criteria/Nasienkriteria If any one of the underlined key phrases in the correct context is omitted, deduct 1 mark./Indien enige van die onderstreepte frases in die korrekte konteks uitgelaat is, trek 1 punt af. When the equilibrium in a closed system is disturbed, the system will re- instate a new equilibrium by favouring the reaction that will cancel/oppose the disturbance.  Wanneer die ewewig in 'n geslote sisteem versteur word, sal die sisteem 'n nuwe ewewig instel deur die reaksie te bevoordeel wat die versteuring kanselleer/teenwerk. (2) 6.2 NOTE/LET WEL Kc =   Wrong Kc expression/Verkeerde Kc- uitdrukking: Max./Maks. ⁄   9,4 =  No Kc expression but correct substitution/Geen Kc-uitdrukking but ∙d -3  korrekte vervanging: Max/Maks. ⁄ (4) 6.3 Increases/Neem toe  (1) 6.4  Increasing/doubling the volume will decrease the pressure.   The reaction that produces a greater number of moles/amount of gas (1 mole gas to 2 moles gas) is favoured.   Reverse reaction is favoured.   Verhoging/verdubbeling van volume sal die druk verlaag.  Die reaksie wat 'n groter aantal mol/hoeveelheid gas (1 mol gas na 2 mol gas) lewer word bevoordeel.  Terugwaartse reaksie word bevoordeel. (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 12 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 6.5 POSITIVE MARKING FROM 6.2./POSITIEWE NASIEN VAN VRAAG 6.2. CALCULATIONS USING CONCENTRATION BEREKENINGE WAT KONSENTRASIE GEBRUIK Marking criteria: (a) Initial concentration is halved.  (b) Change in [CS2] and [S] USING ratio: S : CS2 = 2 : 1  (c) Equilibrium [S] = initial [S] + change in [S]  (d) Equilibrium [CS2] = initial [CS2] - change in [CS2]  (e) CORRECT final answer.  Nasienkriteria: (a) Aanvanklike konsentrasie is gehalveer. (b) Verandering in [CS2] en [S] deur GEBRUIK van verhouding S : CS2 = 2 : 1  (c) Ewewig [S] = aanvanklike [S] + verandering in [S]  (d) Ewewig [CS2] = aanvanklike [CS2] - verandering in [CS2]  (e) KORREKTE finale antwoord.  OPTION 1/OPSIE 1 S CS2 I ii i ( ∙d -3) 0,23 x ½ 0,5 x ½ (a) Aanvangskonsentrasie (mol∙dm-3) = 0,115 = 0,25 h g i i ( ∙d -3) (b) x x Verandering in konsentrasie (mol∙dm-3) Eq i ib i i ( ∙d -3) 0,115 x 0,25 - x Ewewigskonsentrasie (mol∙dm-3) (c) (d) Kc = Wrong Kc expression -x (e) Verkeerde Kc- uitdrukking: Max./Maks. ⁄ 9,4 = ( x Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 13 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne CALCULATIONS USING NUMBER OF MOLES BEREKENINGE WAT GETAL MOL GEBRUIK Marking criteria: (a) n(initial) = c(initial) x 2.  (b) Change in n(S) and n(CS2) USING ratio: S : CS2 = 2 : 1  (c) Equilibrium n(S) = initial n(S) + change in n(S)  (d) Equilibrium n(CS2) = initial n(CS2) - change in n(CS2)  (e) CORRECT final answer.  Nasienkriteria: (a) n(aanvanklik) = c(aanvanklik) x 2  (b) Verandering in n(S) en n(CS2) deur GEBRUIK van verhouding: S : CS2 = 2 : 1  (c) Ewewig n(S) = aanvanklike n(S) + verandering in n(S)  (d) Ewewig n(CS2) = aanvanklike n(CS2) - verandering in n(CS2)  (e) KORREKTE finale antwoord.  OPTION 2/OPSIE 2 S CS2 Initial quantity (mol) 0,46 1 (a) Aanvangshoeveelheid (mol) Change (mol) x 4x (b) Verandering (mol) Quantity at equilibrium (mol)/ (c) 0,46 x 1 – 4x (d) Hoeveelheid by ewewig (mol) Eq i ib i i ( ∙d -3) x x Ewewigskonsentrasie (mol∙dm-3) Kc = Wrong Kc expression - x Verkeerde Kc-uitdrukking: Max./Maks. ⁄ 9,4 = (e) x ( ) (5) 6.6 6.6.1 (Chemical) equilibrium / Rate of the forward and reverse reactions are equal. / Concentrations of reactants and products are constant.  (Chemiese) ewewig / Tempo van voorwaartse en terugwaartse reaksie dieselfde./Konsentrasies van reaktante en produkte is konstant. (1) 6.6.2 Increase in the amount/concentration of S/reactant OR S was added.  Toename in die hoeveelheid/konsentrasie S/reaktans OF S is bygevoeg. (1) 6.6.3 Decrease in temperature/Verlaging in temperatuur  (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 14 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 6.6.4  The rates of the forward and reverse reactions decrease.   The reverse reaction is favoured / faster than the forward reaction. OR The forward reaction decreases more.   A decrease in temperature favours the exothermic reaction.   Die voorwaartse en terugwaartse reaksietempo neem af.  Die terugwaartse reaksie word bevoordeel/is vinniger as die voorwaartse reaksie. OF Die voorwaartse reaksie neem meer af.  'n Verlaging in die temperatuur bevoordeel die eksotermiese reaksie. (3) [21] QUESTION 7/VRAAG 7 7.1 7.1.1 (An acid is a) proton donor/H+ (ion) donor.  (2 or 0) ('n Suur is ʼn) protonskenker/H+(-ioon) skenker. (2 of 0) (2) 7.1.2 (Weak acids) ionise/dissociate incompletely/partially (in water)/have a low Ka value.  (Swak sure) ioniseer/dissosieer onvolledig/gedeeltlik (in water)/het 'n lae Ka- waarde. (1) 7.1.3 H2O  and CH3COO─  (2) 7.2 7.2.1 n(NaOH) = cV  n = (0,167)(0,300)   n(NaOH) = 0,05 mol  (5 x 10-2 mol) (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 15 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 7.2.2 Marking criteria: Nasienkriteria: a) Any formula: pH = -log[H3O+] / a) Enige formule: pH = - log[H3O+] / pH = -log[H+] / pOH = -log[OH─] / pH = - log[H+] / pOH = - log[OH-] / [H3O+][OH─] = - / pH + pOH = 14  [H3O+][OH─] = - / pH + pOH = 14  b) Substitute 11,4 in pH = -log[H3O+]/ b) Vervang 11,4 in pH = - log[H3O+]/ pH + pOH = 14  pH + pOH = 14  c) Substitute calculated [H3O+] in c) Vervang berekende [H3O+] in [H3O+][OH─] / 2,6 in pOH = -log[OH─]  [H3O+][OH─] / 2,6 in pOH = -log[OH─]  d) Final answer: 2,51 x 10-3 mol∙dm-3  d) Finale antwoord: 2,51x 10-3 mol∙dm-3  (0,003 mol∙dm-3) (0,003 mol∙dm-3) OPTION 1/OPSIE 1 pH = - log[H3O+] Any one/Enige een (a) 11,4 (b) = - log[H3O+] OR/OF [H3O+] = 10-11,4 [H3O+] = 3,98 x 10-12 ─ - [H3O+][OH ] = (c) (3,98 x 10-12)[OH─] = 1 x 10-14 [OH-] = 2,51 x 10-3 mol∙dm-3 (d) (0,003) OPTION 2/OPSIE 2 pH + pOH = 14 11,4 + pOH = 14 (b) Any one/Enige een (a) pOH = 2,6 pOH = -log[OH─]  2,6 (c) = -log[OH─] [OH-] = 2,51 x 10-3 mol∙dm-3 (d) (0,003) (4) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 16 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 7.2.3 POSITIVE MARKING FROM QUESTION 7.2.1. AND 7.2.2. POSITIEWE NASIEN VANAF VRAAG 7.2.1. EN 7.2.2. Marking criteria: -3 a) Substitute [NaOH] = ∙d (answer from Q7.2.2) and 0,8 in c =  b) Subtract: n(NaOH)initial (from Q7.2.1) – n(NaOH)mixture  c) Use of ratio: n(OH─) = n(CH3COOH)  d) Substitute 0,5 d (CH3COOH)[calculated by subtraction] into c =  -3 e) Final correct answer: 0,096 mol∙dm  Range: 0,095 to 0,1 ∙d -3 Nasienkriteria: n a) Vervang [NaOH] = 0,00251 mol∙dm-3 (antwoord van Q7.2.2) en 0,8 in c =  b) Trek af: n(NaOH)aanvanklik (vanaf Q7.2.1) – n(NaOH)mengsel  c) Gebruik verhouding: n(OH─) = n(CH3COOH)  n d) Vervang 0,5 en ∆n(CH3COOH) [bereken deur aftrekking] in c =  -3 e) Finale korrekte antwoord: 0,096 mol∙dm  Gebied: 0,095 tot 0,1 mol∙dm-3 n(NaOH)mixture = cV = 0,00251 x 0,8 (a) = 0,002 mol (0,0024) n(NaOH)reacted = 0,05 – 0,002 (b) = 0,048 mol (0,0476) n(NaOH)reacted = n(CH3COOH)used = 0,048 mol (c) [CH3COOH] = = (d) = 0,096 mol∙dm-3 (e) (0,0952) NOTE/LET WEL IF/INDIEN:  Max./Maks. ⁄ b b  Answer from Q7.2.1 substituted in c = to obtain an answer of 0,01 ∙d -3 ./ n Antwoord van Q7.2.1 vervang in c = om 0,01 mol∙dm-3 as antwoord te kry. Max./Maks. ⁄ (6) [18] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 17 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne QUESTION 8/VRAAG 8 8.1 8.1.1 Zn/zinc/sink  (1) 8.1.2 Mn - is a stronger oxidising agent  than Zn2+/Zn(II) ions  and will oxidise Zn  (to Zn2+/Zn(II) ions). - Mn is 'n sterker oksideermiddel as Zn2+/Zn(II)-ione en sal Zn oksideer (na Zn2+/Zn(II)-ione). OR/OF - Zn2+/Zn(II) ion is a weaker oxidising agent  than Mn  and therefore - 2+ Mn will be reduced  (to Mn /Mn(II) ions). 2+ - - Zn /Zn(II) ione is 'n swakker oksideermiddel as Mn en dus word Mn gereduseer (to Mn2+/Mn(II)-ione). (3) 8.2 8.2.1 Provides path for movement of ions. / Completes the circuit. / Ensures electrical neutrality in the cell. / Restore charge balance.  Verskaf pad vir beweging van ione. / Voltooi die stroombaan. / Verseker elektriese neutraliteit in die sel. / Herstel balans van lading. (1) 8.2.2 Mn to/na Ni  (2) 8.2.3 OPTION 1/OPTION 1 NOTE/LET WEL  E cell   Ereduction    E oxidation  Accept any other correct formula from the data sheet. /Aanvaar enige ander korrekte formule = - 0,27– (- 1,18) vanaf gegewensblad. = 0,91 V   Any other formula using unconventional abbreviations, e.g. E°cell = E°OA - E°RA followed by correct substitutions:/Enige ander formule wat onkonvensionele afkortings gebruik, bv. E°sel = E°OM - E°RM gevolg deur korrekte vervangings ⁄ OPTION 2/OPSIE 2 Ni2+ + 2e → Ni E = -0,27   2+  Mn → Mn + 2e E = 1,18  2+ 2+ Ni + Mn→ Mn + Ni E = 0,91 V  (4) 8.2.4 Ni2+ + Mn  → Mn2+ + Ni  Bal.  Marking criteria/Nasienkriteria:  Reactants  Products  Balancing  Reaktanse  Produkte  Balansering   Ignore/Ignoreer ⇌ and phases/en fases  Marking rule 6.3.10/Nasienreël 6.3.10 (3) 8.2.5 Increase/Toeneem  (1) [15] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 18 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne QUESTION 9/VRAAG 9 9.1 ANY ONE:  The chemical process in which electrical energy is converted to chemical energy.  (2 or 0)  The use of electrical energy to produce a chemical change.  The process during which an electric current passes through a solution / molten ionic compound. ENIGE EEN:  Die chemiese proses waarin elektriese energie omgeskakel word na chemiese energie. (2 of 0)  Die gebruik van elektriese energie om 'n chemiese verandering te veroorsaak.  Die proses waar 'n elektriese stroom deur 'n oplossing / gesmelte ioniese verbinding beweeg. (2) 9.2.1 Cr3+(aq) + 3e- → Cr  Marking criteria/Nasienkriteria:  Cr ← Cr3+(aq) + 3e- ( 2 ) 2 Cr (aq) + 3e ⇌ Cr ( 3+ - 1 ) 2 Cr ⇌ Cr3+(aq) + 3e- ( 0 ) 2 3+ - Cr (aq) + 3e ← Cr ( 0 ) 2  Ignore if charge omitted on electron./Ignoreer indien lading weggelaat op elektron.  If charge (+) omitted on Cr3+/Indien lading (+) weggelaat op Cr3+: Example/Voorbeeld: Cr3(aq) + 3e- → Cr Max./Maks: 1 2 (2) 9.2.2 q=I  = (2,5)(10 x 60 x 60)  = 9 x 104 C  (90 000 C) (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 19 DBE/November 2022 NSC/NSS – Marking Guidelines/Nasienriglyne 9.2.3 POSITIVE MARKING FROM QUESTION 9.2.2. POSITIEWE NASIEN VANAF VRAAG 9.2.2. Marking criteria: Nasienkriteria: a) Substitute 1,6 x 10-19 C in n =  a) Vervang 1,6 x 10-19 C in n =  e b) N(Cr) = n(electrons) divide by 3  b) N(Cr) = n(elektrone) gedeel deur 3  c) n(Cr) = N(Cr) divided by NA  c) n(Cr) = N(Cr) gedeel deur NA  d) Substitution of 52 into n =  d) Vervang 52 in n =  e) m(Cr) + 2,2  e) m(Cr) + 2,2  f) Final answer: 18,32 (g)  f) Finale antwoord: 18,32 (g)  Range: 18,32 to 18,40 (g) Gebied: 18,32 tot 18,40 (g) OPTION 1/OPSIE 1 OPTION 2/OPSIE 2 n= / x q n(Cr) = (a & c) x x (b) = = 0,31 mol x - (a) = 5,63 x 1023 electrons m(Cr) = 0,31 x 52 (d) = 16,12 g x N(Cr atoms) = (b) m(X) = 16,12 + 2,2 (e) = 1,88 x 1023 = 18,32 (g) (f) n(Cr) = x = (c) x = 0,31 mol n(Cr) = m(Cr) = 0,31 x 52 (d) = 16,12 g m(X) = 16,12 + 2,2 (e) = 18,32 (g) (f) (6) [13] TOTAL/TOTAAL: 150 Copyright reserved/Kopiereg voorbehou