Physical Sciences Grade 12 Paper 2 North West Mock 2019 Memo

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 12 PHYSICAL SCIENCES: CHEMISTRY (P2) FISIESE WETENSKAPPE: CHEMIE (V2) SEPTEMBER 2019 MARKING GUIDELINE/NASIENRIGLYN MARKS/PUNTE: 150 These marking guidelines consists of 16 pages. Hierdie nasienriglyne bestaan uit 16 bladsye. Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 2 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne QUESTION 1/VRAAG 1 1.1 A PP (2) 1.2 D PP (2) 1.3 C PP (2) 1.4 B PP (2) 1.5 C PP (2) 1.6 A PP (2) 1.7 C PP (2) 1.8 B PP (2) 1.9 D PP (2) 1.10 B PP (2) [20] QUESTION 2/VRAAG 2 2.1 A bond / an atom/ a group of atoms that determine(s) the (physical and chemical ) properties of a group of organic compounds. P P (2 or 0) 'n Binding/ 'n atoom/ 'n groep atome wat die (fisiese en chemiese) eienskappe van 'n groep organiese verbindings bepaal. (2) 2.2 2.2.1 Ketones P/ketone 2.2.2 H ü H C H Marking criteria: H O H H · Only functional group ü correct:/Slegs funksionele H C C C C C H groep korrek. Max: H H · Only two methyl groups/ H H C H Slegs twee metielgroepe: ü · Whole structure correct/ H Hele struktuur korrek: (3) Max: Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 3 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne 2.3 2.3.1 C2H2n-2 P (1) 2.3.2 Accept any correct structural H H H O formula for the given compound. Aanvaar enige H C C C C H korrekte strukturele formule vir die gegewe verbinding. H H H (2) 2.3.3 2-bromo-3-chloro-4-methylpentane 2-bromo-3-chloro-4-metielpentaan Marking criteria: · Stem, i.e. pentane/ Stamnaam is pentaan ü · All three substituents correctly identified/ al drie substituente korrek geïdentifiseer: ü · Correct numbering of substituents and functional group/ Substituente en funksionele groep korrek genommer: ü · Any error e.g. hyphens omitted and/or incorrect sequence/ Enige fout bv.koppelteken uitgelaat en/of foutiewe volgorde: Max. (3) [12] QUESTION 3/VRAAG 3 3.1 3.1.1 Molecular mass (or different homologous series)/ Molekulêre massa (of verskillende homoloë reeks) P (1) 3.1.2 Vapour pressure/ Dampdruk P (1) 3.2 · Butane (alkane) have London/dispersion/induced-dipole forces. P Butaan (alkane) het London/dispersie/geïnduseerde dipoolkragte · Butanol (alcohol) have hydrogen bonding (in addition to the London/dispersion/induced dipole forces and dipole-dipole forces). P Butanol (alkohol) het waterstofbinding (bykomend tot London/dispersie/geïnduseerde dipoolkragte) · The intermolecular forces in alcohol are stronger than the intermolecular forces than in butane(alkanes). P Die intermolekulêre kragte in alkohole is sterker as die intermolekulêre kragte gevind in butaan (alkane). Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 4 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne OR/OF More energy is needed to overcome/break intermolecular forces in Butan-1-ol (alcohols) than in butane (alkanes). Meer energie is nodig om die intermolekulêre kragte in butan-1-ol (alkohole) te oorkom as in butaan (alkane). · Butan-1-ol (alcohols) have lower vapour pressure than alkanes (butane). P Alkohole (butan-1-ol) het ‘n laer dampdruk as butaan (alkane). (4) 3.3 3.3.1 H H H C H H H C C C H PP H H H (2) 3.3.2 2-methylpropane/ 2-metielpropaan PP (2) 3.3.3 Chain (isomer) / ketting (isomeer) P (1) 3.4 D (butan-1-ol). ü Lowest vapour pressure/ strongest intermolecular forces ü Laagste dampdruk/ sterkste intermolekulêre kragte. (2) [13] QUESTION 4/VRAAG 4 4.1 4.1.1 - Room temperature /kamertemperatuur P - Absence of water/Geen water nie P (2) 4.1.2 2-chlorobutane / 2-chlorobutaan PP (2) 4.2.1 addition/hydrohalogenation P addisie/hidrohalogenering (1) 4.2.2 substitution/hydrolysis P (1) substitusie/hidrolise 4.2.3 elimination/dehydration. P (1) eliminasie/dehidrasie 4.3 4.3.1 - Secondary/sekondêre P - Carbon atom to which the OH-group is attached, is attached to two other carbon atoms. üü/Koolstofatoom waaraan OH- vebind is, is verbind aan twee ander koolstofatome. (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 5 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne 4.3.2 ANY ONE/ENIGE EEN: Ÿ (Alcohol/ethanol) is flammable/catches fire easily. P (Alkohol/etanol) is vlambaar/slaan maklik aan die brand. Ÿ To heat it evenly./Om dit eweredig te verhit. Ÿ Water bath is used for low heat/low temperature./Waterbad word gebruik vir lae hitte/lae temperatuur. Ÿ Alcohol/ethanol will evaporate too quickly./(Alkohol/etanol) sal te vinnig verdamp. Accept/Aanvaar: (Alcohol/ethanol) is volatile./(Alkohol/etanol) is vlugtig. (1) 4.4.1 A polymer formed by monomers with two functional groups üthat are linked together in a condensation reaction in which a small molecule, usually water, is lost. ü 'n Polimeer wat gevorm word deur twee monomere met verskillende funksionele groepe ü wat aan mekaar skakel in 'n kondensasiereaksie waarin 'n klein molekuul, gewoonlik water, verloor word .P (2) 4.4.2 A P (1) 4.4.3 C2H4 ü (1) [15] QUESTION 5/VRAAG 5 5.1.1 The number of particles with sufficient kinetic energy for a reaction to take place/successful collision/effective collision/energy higher than Ea. P Die aantal deeltjies met voldoende kinetiese energie vir ‘n reaksie om plaas te vind/suksesvolle botsings/effektiewe botsings/energie hoër as Ea. (1) 5.1.2 Graph B/grafiek B P (1) 5.2.1 (a) Marking guideline/Nasienriglyne Dependent and independent variables correctly identified. Afhanklike en onafhanklie veranderlikes korrek ü geïentifiseer. Relationship between variables in question form. ü Verwantskap tussen veranderlikes in vraagvorm. Ÿ What is the influence of state of division/ surface area on reaction rate? Ÿ Wat is die invloed van toestand van verdeeldheid/ reaksieoppervlakte op reaksietempo? Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 6 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne (b) ANY TWO OF: Temperature, mass of magnesium, concentration of HCℓ üü ENIGE TWEE VAN: Temperatuur, massa magnesium, konsentrasie HCℓ (2) 5.2.2 Reaction is complete/ all Mg is used up/ Mg is the limiting reagent. P Reaksie het volledig verloop/ al die magnesium het gereageer/ Mg is die beperkte reaktant. (1) 5.2.3 Graph of Volume of H2 (cm3) vs time (min) / Grafiek van volume H2 (cm3) teenoor tyd (min) 40 EXPERIMENT 2/ 35 EKSPERIMENT 2 30 Volume H2 (cm3) 25 EXPERIMENT 1/ EKSPERIMENT 1 20 15 10 5 0 0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 Time /tyd (min) Marking criteria Labelled x- and y-axes/ Byskrifte van x- en y-as P Plotting of points/ Stip van punte P Labelling graph/ Benoem grafieke ü Shape of graph/ vorm van grafiek: Experiment 1/Eksperiment 1 P Experiment 2/Eksperiment 2 P (5) 5.2.4 Experiment 2/ eksperiment 2 P (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 7 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne 5.2.5 Reaction surface area of Mg increases/ powdered Mg has a larger surface area / more contact pointsP more effective collisions with the correct orientation ü per unit time ü/ Frequency of effective collisions increases. Reaksie-oppervlakte van Mg is verhoog/ Poeier van Mg het ‘n groter reaksie-oppervlakte/meer kontakpunte ü, meer effektiewe botsings met die regte oriëntasie ü per tydseenheid ü /Frekwensie van effektiewe botsings neem toe. (3) Δvolume H₂ 5.2.6 Rate of reaction/ reaksietempo = Δ time/tyd (15 - 0)ü = (0,5 - 0)ü = 30 cm3 . min-1 ü (3) [18] QUESTION 6/VRAAG 6 6.1 A system without external force/ influence/ ’n sisteem sonder eksterne kragte/invloede. PP (2) 6.2 Endothermic/ endotermies P Heat is added to reagents/heat appears on the left hand side of the equation/ Hitte word by reaktante gevoeg/ warmte verskyn aan die linkerkant van die vergelyking. P (2) 6.3 Larger than/ Groter as. P Kc > 1P /Kc large/groot (2) 6.4 Marking guidelines/Nasienriglyne n · Substituting/vervang 28 g.mol-1 in n = P m · USE ratio/GEBRUIK verhouding: CO2 : CO = 1:2 P · n(CO2)eq/ewe = n(CO2)initial/begin - ∆n(CO2). n(CO2)eq/ewe = n(CO)initial/begin + ∆n(CO). ü · Divide equilibrium moles by 2 dm3/Deel ewewigsmol deur 2 dm3. P · Correct Kc expression (formulae in square brackets). P Korrekte Kc uitdrukking (formules in vierkanthakies). · Substitution of Kc value/Vervanging van Kc-waarde. P · Substitution of concentrations into correct Kc expression. P Vervanging van konsentrasies in korrekte Kc-uitdrukking. Ÿ Final answer/Finale antwoord: 4,29 (mol) P Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 8 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne OPTION 1/OPSIE 1 m n = M 168 = P 28 = 6 mol CO2(g) CO(g) Mole ratio 1 2 Initial moles/Aanvangsmol X 0 Moles reacted/mol gereageer 3 6P (ratio) P Moles at equilibrium/mol by ewewig X-3P 6P Equilibrium concentration/ X-3/2 3 -3 Ewewigskonsentrasie (mol·dm ) P (divide by 2/deel deur 2) [CO ] P 2 Kc = [CO2 ] 2 14 = (3) P x -3 ( ) 2 X = 4,29 mol P (9) OPTION 2/OPSIE 2 m n(CO at eq) = M 168 = P 28 = 6 mol n c= v = 6 P divide by 2/deel deur 2 2 = 3 mol Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 9 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne CO2(g) CO(g) Mole ratio 1 2 Initial concentration/Aanvangskonsentrasie X 0 -3 Change in concentration(mol·dm ) 1,5P 3P(ratio) Equilibrium concentration/ X- 1,5P 3 -3 Ewewigskonsentrasie (mol·dm ) 2 [ CO ] Kc = P [ CO ]2 2 (3) 14 = P ( x - 15) -3 X = 2,14 mol·dm P n(CO2) = c V = 2,14 x 2 = 4,29 mol P OPTION 3/OPSIE 3 m n(CO at eq) = M = 168 P 28 = 6 mol CO2(g) CO(g) Mole ratio 1 2 Initial moles/Aanvangsmol 4,28 0 Moles reacted/mol gereageer 3 6P (ratio) P Moles at equilibrium/mol by ewewig 1,28P 6P Equilibrium concentration/ 0,64 3 multiply by 2P -3 Ewewigskonsentrasie (mol·dm ) 2 [ CO ] Kc = P [ CO ]2 2 (3) 14 = P [CO ]2 -3 [CO2] = 0,64 mol·dm P 6.5 Remains the same/ Bly dieselfde P (1) [16] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 10 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne QUESTION 7/VRAAG 7 7.1.1 It is a proton donator/ protonskenker. P (2) 7.1.2 An acid that donates ONLY one proton per molecule.PP ’n Suur wat slegs EEN PROTON per molekule skenk. (2) 7.1.3 Strong acid / sterk suurP It completely ionises in water /Dit ioniseer volledig in waterP (2) 7.1.4 (a) [H3O+][OH-] = kw = 1 x 10-14 P [H3O+](1x 10-11) P = 1 x 10-14 [H3O+] = 1 x 10-3 mol∙dm-3P (3) (b) pH = - log [H3O+] P pH = -log (10-3) P pH = 3P (3) 7.2 7.2.1 CO3-2(aq) + H2O(aq) P⇌ HCO3-(aq)+ OH- (aq)P bal P (3) N.B. Accept/Aanvaar single arrow/enkel pyl (→) Phases not necessary/ fases nie nodig. 7.2.2 HCO3- P (1) 7.2.3 n = m P M 4,24 = P 106 = 0,04 mol HCℓ : Na2CO3 = 1:2 Thus n(HCℓ) = 2(0,04) = 0,08 molP c= n P V 0,08 = P 0,25 = 0,32 mol·dm-3P OR/OF Ca Va na = P Cb v b nb c a (0,25) 2 P = P (0,04) 1 P Ca(0,25) P = 0,08 mol·dm-3 P Ca = 0,32 mol·dm-3P (6) [22] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 11 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne QUESTION 8/VRAAG 8 8.1 Galvanic/Voltaic (cell)/ Gavaniese/voltaïese (sel). P (1) 8.2 8.2.1 Ba(s) → Ba2+(aq) + 2e- PP (2) 8.2.2 Barium to Iodine/ Barium na jodium P (1) 8.2.3 Ba(s) / Ba2+ (aq) P (1 mol.dm3) // P I -(aq) / I2(g) / Pt P (3) OR/OF Ba(s )/ Ba2+ (aq) // I -(aq) / I2(g) / Pt OR/OF Ba(s) / Ba2+ // I - / I2 / Pt Notes/Aantekeninge Accept any other correct formula from the data sheet/Aanvaar enige ander korrekte 8.3. OPTION 1/OPSIE 1 formule vanaf die gegewensblad. Eɵcell = Eɵcathode - Eɵanode P Any other formula using unconventional abbreviations, e.g. Eɵ sel = EɵOA- EɵRA followed Eɵ sel = Eɵkatode - Eɵanode by correct substitutions:/ Enige ander formule wat onkonvensionele afkortings gebruik bv. = +0,54 P - (-2,90) P Eɵ sel = EɵOM - EɵRM gevolg deur korrekte = +3,44 V P vervangings: Max/Maks: OPTION 2/ OPSIE 2 Ba(s) → Ba2+ + 2e- Eɵ = +2,90 VP 2I- + 2e- → I2(g) Eɵ = +0,54 VP 2I-(aq) + Ba(s) → I2(s) + Ba2+(aq) Eɵ = +3,44 V P (4) 8.4 Spontaneous.P The emf / Eɵcell is positive P/It produces electrical energy. Spontaan. Die emk/ Eɵsel is positief/ dit produseer elektriese energie (2) 8.5 Decreases. / VerlaagP (1) [14] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 12 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne QUESTION 9/VRAAG 9 9.1 The chemical process in which electrical energy is converted to chemical energy.PP Die proses waarin die elektiese energie omgeskakel word na chemiese energie. (2) 9.2 9.2.1 2H2O + 2e- → H2(g) + 2OH- (aq) PP (2) 9.2.2 Chlorine gas/chloorgas/ Cℓ2(g) P (1) 9.2.3 2H2O(ℓ) + 2Cℓ- (aq)ü → Cℓ2(g) + H2(g) + 2OH- (aq) P Bal P (3) [8] QUESTION 10/VRAAG 10 10.1 10.1.1 Haber (process)/Haber (proses)P (1) 10.1.2 Platinum P (1) 10.1.3 N2(g) + 3H2(g) ü → 2NH3(g) P bal P (3) 10.1.4 NH4NO3 P and / en (NH4)2SO4 P (2) 10.2 10.2.1 Ammonium nitrate.P It provides nitrogen for healthy leaves. P Ammoniumnitraat. Dit gee stikstof wat gesonde blare bevorder. (2) 10.2.2 M(NH4NO3) = 14 + 1(4) + 14 + 3(16) = 80 g·mol -1 P 28 %N= P x 100 80 = 35 % P (3) [12] TOTAL/TOTAAL: 150 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 13 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne NW DEPARTMENT OF EDUCATION Physical Sciences Grade 12 Paper 2 NSC SEPT 2019 ANALYSIS GRID Taxonomy Knowledge area Marks MATTER & MATERIALS Knowledge,Recall, Low CHEMICAL SYSTEMS APPLICATION, CHEMICAL CHANGE COMPREHENSION, Question Totals Question No. ANALYSIS, Problem TOTAL MARKS Solving TOTAL SYNTHESIS, EVALUATION,Higher Basic Questions Demand Abilities, Hard new problems, Challenge Level Content E M D E M D E M D E M D 150 Marks 150 1.1 Hydocarbon 2 2 2 2 1.2 Sructural formula 2 2 2 2 1.3 IUPAC name 2 2 2 2 1.4 Empirical formula 2 2 2 2 1.5 Acids and bases 2 2 2 2 1.6 Energy diagram 2 2 2 2 1.7 Acids and bases 2 2 2 2 1.8 Equilibrium 2 2 2 1.9 Electrochemistry 2 2 2 2 1.10 Fertilisers 2 2 2 2 20 2.1 Organic compounds 2 2 2 2 2.2.1 Homologous series 1 1 1 1 2.2.2 Structural formula 3 3 3 3 2.3.1 General formula 1 1 1 2.3.2 Isomers 2 2 2 2 2.3.3 IUPAC name 3 3 3 3 12 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 14 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne 3.1.1 Physical poperties 1 1 1 1 3.1.2 Physical poperties 1 1 1 1 3.2. Physical poperties 4 4 4 4 3.3.1 Isomers 2 2 2 2 3.3.2 Isomers 2 2 2 2 3.3.3 Isomers 1 1 1 1 3.4 Boiling point 2 2 2 2 13 4.1.1 Reaction conditions 2 2 2 2 4.1.2 IUPAC name 2 2 2 2 4.2.1 Type of reaction 1 1 1 1 4.2.2 Type of reaction 1 1 1 1 4.2.3 Type of reaction 1 1 1 1 4.3.1 Secondary alcohol 1 3 3 3 4.3.2 Heating of alcohols 1 1 1 1 4.4.1 Polymers 1 2 2 2 4.4.2 Polymers 1 1 1 1 4.4.3 Monomer 1 1 1 1 15 5.1.1 Reaction rate 1 1 1 1 5.1.2 Reaction rate 1 1 1 1 5.2.1(a) Investigative question 2 2 2 2 5.2.1(b) Controlled variables 2 2 2 2 5.2.2 Interpretation of table 1 1 1 5.2.3 Graph 4 4 4 4 5.2.4 Reaction rate 1 1 1 1 1 1 5.2.5 Collision theory 3 3 3 3 5.2.6 Reaction rate 3 3 3 3 18 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 15 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne 6.1 Cosed system 2 1 2 2 2 6.2 Endo- or exothermic 2 2 2 2 2 6.3 Equilibrium 2 2 2 2 6.4 Equilibrium 9 9 9 9 6.5 Equilibruim 1 1 1 1 16 7.1.1 Bronsted-Lowry acid 2 2 2 2 7.1.2 Monoprotic acid 2 2 2 2 7.1.3 Weak/strong acid 2 2 2 2 7.1.4(a) Concentration of hydronium ions 3 3 3 3 7.1.4(b) Calculation of pH 3 3 3 3 7.2.1 Hydrolysis 3 3 3 3 7.2.2 Conjugate acid 1 1 1 1 7.2.3 Concentration calculation 6 6 6 6 22 8.1 Type of Electrochemical cell 1 1 1 1 8.2.1 Oxidation half-reaction 2 2 2 2 8.2.2 Electron flow 1 1 1 1 8.2.3 Cell notation 3 3 3 3 8.3 Calculating emf 4 4 4 4 8.4 Electrochemical cells 2 2 2 2 8.5 Electrochemical cells 1 1 1 1 14 9.1 Electrlysis 2 2 2 2 9.2.1 Half-cell reaction 2 2 2 2 9.2.2 Electrochemistry 1 1 1 1 9.2.3 Overall reaction 3 3 3 3 8 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com Physical Sciences P2/Fisiese Wetenskappe V2 16 NW/September 2019 NSC/NSS – Marking guidelines/Nasienriglyne 10.1.1 Haber 1 1 1 1 10.1.2 Catalyst 1 1 1 1 10.1.3 Fertilisers 3 3 3 3 10.1.4 Formulae of fertilisers 2 2 2 2 10.2.1 Fertilisers 2 2 2 2 10.2.2 Fertilisers 3 3 3 3 12 5 17 2 21 25 9 21 19 17 0 14 0 150 40 70 20 150 24 55 57 14 150 50 84 16 16,0% 36,7% 38,0% 9,3% 33,3 56,0 10,7 15% 40% 35% 10% 48% 84% 18% Overall E M D 36 66 43 27,3% 44% 28,7% 30 40 30 Copyright reserved/Kopiereg voorbehou