Physical Sciences Grade 12 P2 Eastern Cape June 2021 Memo

NATIONAL SENIOR CERTIFICATE/ NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 12 JUNE/JUNIE 2021 PHYSICAL SCIENCES: CHEMISTRY P2 MARKING GUIDELINE/ FISIESE WETENSKAPPE: CHEMIE V2 NASIENRIGLYN (EXEMPLAR/EKSEMPLAAR) MARKS/PUNTE: 150 This marking guideline consists of 15 pages./ Hierdie nasienriglyn bestaan uit 15 bladsye.

2 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/JUNE/JUNIE 2021) QUESTION 1/VRAAG 1 1.1 D ✓✓ (2) 1.2 D ✓✓ (2) 1.3 A ✓✓ (2) 1.4 C ✓✓ (2) 1.5 C ✓✓ (2) 1.6 D ✓✓ (2) 1.7 B ✓✓ (2) 1.8 B ✓✓ (2) 1.9 B ✓✓ (2) 1.10 C ✓✓ (2) [20] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/JUNE/JUNIE 2021) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 3 QUESTION 2/VRAAG 2 2.1 2.1.1 Homologous series ✓ Homoloë reeks (1) 2.1.2 Unsaturated. ✓ Contains a triple bond ✓/multiple bonds Onversadig Bevat driedubbelbinding/veelvoudige bindings (2) 2.1.3 C5H9 ✓ (1) 2.1.4 5-ethlyl ✓ -2-methyl ✓ hex-3-yne ✓ OR 5-ethlyl-2-methyl-3-hexyne Marking Criteria/Nasien- 5-etiel-2-metielheks-3-yn kriteria OF 5-etiel-2-metiel-3-heksyn • Hexyne ✓ heksyn • Side chains (ethyl and methyl) ✓ • Syketting (etiel en metiel) • Whole name correct ✓ Volledige naam korrek (3) 2.2.1 Marking criteria/Nasien- H kriteria ✓ H H O • Functional group correct (1/2) H C C C H✓ Funksionele groep H H H korrek (1/2) • Whole structure correct (2/2) Volle struktuur korrek (2/2) (2) 2.2.2 (Mild) heat ✓ in a water bath ✓ (Matige) hitte in ʼn waterbad (2) 2.2.3 Esterification/ Condensation ✓ Esterifikasie/kondensasie (1) 2.2.4 H2SO4 ✓ (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

4 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/JUNE/JUNIE 2021) 2.2.5 Marking criteria/Nasien riglyne O H H H ✓ • Functional group H C O C C C H ✓ correct (1/2) Funksionele groep H H H (1/2) • Whole structure correct (2/2) Volle struktuur korrek (2/2) (2) 2.3 2.3.1 Compounds with the same molecular formula. ✓ but different structural formula. ✓ Verbindings met dieselfde molekulêre formule maar verskillende struktuurformule. (2) 2.3.2 The C atom bonded to Br is bonded to one other C atom ✓✓ OR The C atom bonded to Br is bonded to two hydrogen atoms Die C atoom wat aan die Br gebind is, is aan een ander C atom gebind OF Die C atoom gebind aan die Br is aan twee waterstofatome gebind. (2) 2.3.3 1-bromo-2-methylpropane ✓✓✓ 1-bromo-2-metielpropaan Marking Criteria/Nasien- kriteria • Propane ✓ Propaan • (bromo and methyl) ✓ (bromo en metiel) • Whole name correct ✓ Volle naam korrek (3) [22] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/JUNE/JUNIE 2021) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 5 QUESTION 3/VRAAG 3 3.1 The temperature at which the vapour pressure of a liquid equals the atmospheric pressure. ✓✓ Die temperatuur waarteen die dampdruk van ʼn vloeistof gelyk is aan die atmosferiese druk. (2) 3.2 A ✓ Compound A has the lowest boiling point. ✓ Verbinding A het die laagste kookpunt. (2) 3.3.1 Molar mass/ Molecular size/ Surface area ✓ Molêre massa/ Molekulêre grootte/Oppervlakte (1) 3.3.2 Hydrogen bond ✓ Waterstofbinding (1) 3.4 • The molar mass/Molecular size/ surface area of the compounds increases from top to bottom in the table. ✓ • The compounds have London forces and (Hydrogen bonds) ✓ • The strength of London forces increases with an increase in molar mass/molecular size/surface area. ✓ • More energy is needed to overcome the intermolecular forces ✓ • Die molêre massa/molekulêre grootte/oppervlakte van die verbinding neem toe van bo na onder in die tabel. • Die verbindings het Londonkragte en (waterstofbindings) • Die sterkte in Londonkragte neem toe met ʼn toename in molêre massa/molekulêre grootte/oppervlakte • Meer energie word benodig om die intermolekulêrekragte te oorkom (4) 3.5.1 Marking criteria/Nasien H kriteria H H C H H • 3 Carbon atoms in longest chain H C C C O- H✓✓ with correct functional group H H H 3 koolstofatome in die langste ketting en korrekte funksionele groep (2) • Whole structure correct(2/2) 3.5.2 B ✓ It has the same molecular formula ✓ Dit het dieselfde molekulêre formule Volle struktuur (2) korrek (2/2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

6 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/JUNE/JUNIE 2021) 3.5.3 Lower than ✓ Laer as. (1) 3.5.4 • 2-methylpropan-1-ol has a smaller surface area than butan-1-ol. ✓ • Both compounds have London forces and (hydrogen bonds) ✓ • 2-methylpropan-1-ol have weaker London forces than butan-1-ol ✓ • Less energy is needed to overcome the intermolecular forces in 2-methylpropan-1-ol ✓ • 2-metielpropan-1-ol het ʼn Kleiner oppervlakte as butan-1-ol • Beide verbindings het Londonkragte en (waterstofbinding) • 2-metielpropan-1-ol het swakker Londonkragte as butan-1-ol • Minder energie word benodig om die intermolekulêrekragte in 2-metielpropan-1-ol te oorkom OR/OF • Butan-1-ol has a larger surface area than 2-methylpropan-1-ol ✓ • Both compounds have London forces and (hydrogen bonds) ✓ • Butan-1-ol have stronger Londonforces than 2-methylpropan-1-ol ✓ • More energy is needed to overcome the intermolecular forces in butan-1-ol ✓ • Butan-1ol het ʼn groter oppervlakte as 2-metielpropan-1-ol • Beide verbindings het Londonkragte en (waterstofbinding) • Butan-1-ol ol het sterker Londonkragte as 2-metielpropan-1-ol • Meer energie word benodig om die intermolekulêrekragte in butan-1-ol te oorkom (3) 3.6 • Methanoic acid and propan-1-ol have both Hydrogen bond and (London forces) ✓ • Methanoic acid have two sites for hydrogen bonds while propan-1-ol have only one site for hydrogen bonds. ✓ • Methanoic acid has stronger intermolecular forces than propan-1-ol ✓ • More energy is needed to overcome the intermolecular forces in methanoic acid. ✓ • Metanoësuur en propan-1-ol het beide waterstofbinding en (Londonkragte) • Metanoësuur het twee plekke vir waterstofbinding terwyl propan-1-ol slegs een plek het vir waterstofbinding • Metanoësuur het sterker intermolekulêrekragte as propan-1-ol • Meer energie word benodig om die intermolekulêrekragte te oorkom metanoësuur OR/OF Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/JUNE/JUNIE 2021) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 7 • Methanoic acid and propan-1-ol have both Hydrogen bond and (London forces) ✓ • Methanoic acid have two sites for hydrogen bonds while propan-1-ol have only one site for hydrogen bonds. ✓ • Propan-1-ol has weaker intermolecular forces than methanoic acid ✓ • Less energy is needed to overcome the intermolecular forces in propan-1-ol. ✓ • Metanoësuur en propan-1-ol het beide waterstofbinding en (Londonkragte) • Metanoësuur het twee plekke vir waterstofbinding terwyl propan-1-ol slegs een plek het vir waterstofbinding • Propan-1-ol het swakker intermolekulêrekragte as metanoësuur • Minder energie word benodig om die intermolekulêrekragte te oorkom in propan-1-ol (4) [22] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

8 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/JUNE/JUNIE 2021) QUESTION 4/VRAAG 4 4.1 Process of breaking down long chain hydrocarbons ✓/alkanes into smaller more useful chains ✓ Proses van opbreek van lang ketting koolwaterstowwe/alkane na kleiner meer bruikbare kettings (2) 4.2 4.2.1 C4H10 ✓✓ (2) 4.2.2 HIGH TEMPERATURE ✓ OR HIGH PRESSURE HOË TEMPERATUUR OF HOË DRUK (1) 4.3 4.3.1 Substitution ✓ Substitusie (1) 4.3.2 Elimination ✓ Eliminasie (1) 4.4 Hydrogenation ✓ Hidrogenasie (1) 4.5 4.5.1 Br2/Bromine ✓ Br2/ Broom (1) 4.5.2 Pt/Ni/Pd/Platinum/Nickel/Palladium ✓ Pt/Ni/Pd / Platinum/Nikkel/ Palladium (1) 4.6 CH3CH2CH2CHBr ✓✓+ KOH CH3CH = CHCH3 ✓✓ + KBr + H2O Marking criteria/Nasienkriteria • Organic reactant ✓✓ Organiese reaktant • Organic product ✓✓ Organiese produk • ALL Inorganic reagents correct ✓ (KOH, KBr and H2O) ALLE anorganiese reagense korrek (KOH, KBr en H2O (5) [15] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/JUNE/JUNIE 2021) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 9 QUESTION 5/VRAAG 5 5.1 Change in concentration (of reactant/products) per unit time ✓✓ Verandering in konsentrasie (van reaktante/produkte) per eenheidstyd OR/OF Amount/Volume/Mass of reactant/product used/formed per unit time Hoeveelheid/volume/Massa van reaktante/produkte gebruik/gevorm per eenheidstyd (2) 5.2 RELEASED ✓ VRYGESTEL ΔH < 0 ✓/Energy of products is less than the energy of reactants/ Reaction exothermic ΔH < 0/ Energie van produkte is minder as die energie van die reaktante/ Reaksie is eksotermies (2) 5.3 5.3.1 INCREASES ✓ VERHOOG (1) 5.3.2 NO EFFECT ✓ GEEN EFFEK (1) 5.4 5.4.1 After 120 s ✓ Na 120 s (1) 5.4.2 Concentration (of HCℓ) ✓ Surface area (of Zinc) ✓ OR temperature Konsentrasie (van HCℓ) Oppervlak (van Sink) OF temperatuur (2) 5.5 5.5.1 Rate / Tempo = Δv/Δt= 300 -0✓ /120 – 0 ✓= 2,50 cm3∙s-1 ✓ (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

10 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/JUNE/JUNIE 2021) 5.5.2 n=V/Vm ✓ OR/OF pV = nRT n= 250 × 10-3 ✓ (101,3×103)(250×10-6) = n (8,31)(20+273)✓ 24 n= 0,01 mol H2 produced/geproduseer n = 0,01 mol H2 produced/geproduseer NOTE/LET WEL: Mole ratio HCℓ: H2 If the above formula was Mol verhouding 2 :1 used to calculate the mole of H2 then award formula n((HCℓ) = 2 n (H2) mark for m= nM n((HCℓ) = 2(0,01) ✓ n((HCℓ) = 0,02 mol reacted As die bostaande formule gebruik was om die mol van H2 te bereken, dan die toekenningsformule- punt vir m=nM Mole Option/ Mol Opsie Mass Option/Massa Opsie n= cV m = nM n = (0,5)( 50×10-3) ✓ m = (0,02)(36,5) ✓ n = 0,025 mol initially m = 0,73 g reacted aanvanklik reageer n (left) = n (initially) – n (reacted) m = cMV n (left) = 0,025 – 0,02 ✓ m = (0,5)(36,5)(50×10-3) ✓ n (left) = 0,005 mol m = 0,9125 g initially m = nM m(left) = m (i) – m (r) m = (0,005)(36,5) ✓ m (left) = 0,9125 – 0,73 ✓ m = 0,1825 g ✓ m (left) = 0,1825 g ✓ (7) 5.6 5.6.1 Catalyst ✓ OR Increases reaction rate Katalisator OF Toename in reaksie-tempo (1) 5.6.2 • Catalyst lowers activation energy/provides an alternative path of lower activation energy ✓ Katalisator verlaag die aktiveringsenergie/ bied ʼn alternatiewe pad van laer aktiveringsenergie • More particles have sufficient Ek OR more particles have Ek>Ea ✓ Meer deeltjies het genoeg Ek OF meer deeltjie het Ek>Ea • More effective collisions per unit time/Frequency of effective collisions increase ✓✓ Meer effektiewe botsings per eenheidstyd/ Frekwensie van die effektiewe botsings neem toe (4) [24] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/JUNE/JUNIE 2021) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 11 QUESTION 6/VRAAG 6 6.1 Reaction in which products can be converted back to reactants ✓✓ (2 or 0) Reaksie waarin produkte terug na reaktante oorgeskakel word (2 of 0) (2) 6.2 6.2.1 Decreases ✓ Verlaag (1) 6.2.2 Increases ✓ Verhoog (1) 6.3 • (When the temperature is decreased) the exothermic reaction is favoured ✓ • Forward reaction is favoured ✓ (Wanner die temperatuur verlaag) word die eksotermiese reaksie bevoordeel Voorwaartse reaksie word bevoordeel (2) 6.4 CALCULATION USING MOLES/BEREKENINGE DEUR MOL TE GEBRUIK Marking guideline/Nasienriglyn • Formula/formule n=m/M • Substitution of/Substitusie van 28 g∙mol-1 • Use of ratio/Gebruik van verhouding N2:H2:NH3 • Equilibrium amounts of N2 and H2 formed/ Ewewigshoeveelheid van N2 en H2 gevorm • Division n equilibrium of N2, H2 and NH3 by 2 / Deel van n ewewig van N2, H2 en NH3 deur 2 • Correct Kc expression/Korrekte Kc uitdrukking • Substitution into Kc expression/substitusie in Kc uitdrukking • Final answer/Finale antwoord n = m/M ✓ = 7,84/28 ✓ = 0,28 mol N2 + 3 H2 ⇋ 2 NH3 ni (mol) 0,28 0,6 0 Δn (mol) 0,06 0,18 0,12 Ratio ✓/Verhouding ne (mol) 0,22 0,42 ✓ 0,12 ce 0,22/2 0,42/2 0,12/2 Division by 2 ✓/Deel met 2 (mol∙dm-3) =0,11 0,21 0,06 Kc = [NH3]2/[N2].[H2]3 ✓ = 0,062/(0,11 x 0,213) ✓ = 3,53 ✓ Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

12 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/JUNE/JUNIE 2021) CALCULATION USING CONCENTRATION/BEREKENIGE DEUR GEBRUIK TE MAAK VAN KONSENTRASIE Marking guidelines/ Nasienriglyne • Formula / Formule c=m/MV or c=n/v • Substitution into/ Substitusie in c=m/MV or c=n/V • Dividing by 2 for all concentration/ Deel deur 2 vir alle konsentrasies • Use of ratio/ Gerbuik van verhoudings N2:H2:NH3 • Equilibrium concentrations of/ Ewewig konsentrasies van N2, H2 and NH3 • Correct Kc expression/Korrekte Kc uitdrukking • Substitution into Kc expression/ Substitusie in Kc uitdrukking • Final answer /Finale antwoord ✓ (Any one/Enige een) c (N2) = m/MV c (H2) = n/V c (NH3) = n/V c (N2) = 7,84/(28)(2) ✓ c (H2) = 0,6/2 c (NH3) = 0,12/2 c (N2) = 0,14 mol∙dm -3 c (H2) = 0,3 mol∙dm c (NH3) = 0,06 mol∙dm-3 -3 (dividing by/deel van 2) ✓ N2 + 3 H2 → 2 NH3 ci 0,14 0,3 0 Δc -0,03 -0,9 +0,06 ratio ✓/verhouding ceq 0,11 0,21 0,06 ✓ Kc = [NH3]2/[N2]∙[H2]3 ✓ = 0,062/(0,11 x 0,213) ✓ = 3,53 ✓ (8) 6.5 As pressure increases percentage yield increases. ✓✓ As die druk toeneem, neem die persentasie opbrengs toe. (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/JUNE/JUNIE 2021) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 13 6.6 MOLE OPTION / MOLOPSIE Ratio/Verhouding N2 : H2 Ratio/Verhouding N2 : H2 1: 3 1 :3 n(H2) = 3 (0,28) ✓ n(N2) = 1/3 (0,6) n(H2) = 0,84 mol of H2 needed n(N2) = 0,2 mol of N2 needed only 0,6 mol of H2 is available 0,28 mol of N2 is available 0,84 mol van H2 word benodig 0,2 mol N2 word benodig Slegs 0,6 mol van H2 is beskikbaar 0,28 mol N2 is beskikbaar ∴ H2 is the limiting reagent ✓ ∴ H2 is the limiting reagent ∴H2 is die beperkende reagens ∴ H2 is die beperkende reagens Theoretical yield/Teoretiese opbrengs = 0,6 x 2/3 = 0,4 mol ✓ % Yield/Opbrengs = actual yield (werklike opbrengs)/theoretical yield(teoretiese opbrengs) × 100 % = 0,12/0,4 x 100 ✓ = 30% Pressure / Druk= 100 (atmospheres/atmosfeer) ✓ CONCENTRATION OPTION/KONSENTRASIE-OPSIE • V is constant/V is konstant • Concentration ratio N2 : H2 Concentration ratio N2 : H2 Konsentrasie-verhouding 1: 3 Konsentrasie-verhouding 1: 3 c(H2) = 3 (0,14) ✓ c(N2) = 1/3 (0,3) c(H2) = 0,42 mol∙dm-3 of H2 required c(N2) = 0,1 mol∙dm-3 H2 benodig only 0,3 mol∙dm-3 is available 0,14 mol∙dm-3 is available slegs 0,3 mol∙dm-3 is beskikbaar 0,14 mol∙dm-3 is beskikbaar ∴ H2 is the limiting reagent/is die beperkende reagens ✓ Theoretical yield/teoretiese opbrengs = 0,3×2/3 ✓= 0,2 mol∙dm-3 % yield/opbrengs = actual yield (werklike opbrengs)/theoretical yield/teoretiese opbrengs ×100 % % yield/opbrengs = 0,06/0,2 ×100 % ✓ % yield/opbrengs = 30 % Pressure/druk 100 (atmosphere/atmosfeer) ✓ (5) [21] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

14 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/JUNE/JUNIE 2021) QUESTION 7/VRAAG 7 7.1 7.1.1 Reaction of a salt with water ✓✓ Reaksie van ʼn sout met water (2) 7.1.2 (Excess) Hydroxide/OH- ions are formed ✓ Hydroxide/ OH- is basic/alkaline ✓ (Oormaat) Hidroksied/ OH- ione word gevorm Hidroksied/ OH- is basies/alkalies (2) 7.1.3 H2O ✓ and HCO3- ✓ (2) 7.1.4 HCO3- can accept a proton (H+) (to form H2CO3) ✓ HCO3- can donate a proton (H+) (to form CO32-) ✓ HCO3- kan ʼn proton (H+) aanvaar (om H2CO3 te vorm) HCO3- kan ʼn proton (H+) skenk (om CO32- te vorm) (2) 7.2 7.2.1 Acid is a proton donor ✓✓ Suur is ʼn protonskenker (2) 7.2.2 pH = - log [H3O+] ✓ 1 = - log [H3O+] ✓ [H3O+] = 0,1 mol∙dm -3 ✓ [X] = 2 [H3O+] [X] = 2(0,1) [X] = 0,2 mol∙dm -3 ✓ (4) 7.2.3 It is a solution of known concentration ✓✓ Dit is ʼn oplossing met bekende konsentrasie. (2) 7.2.4 Bromothymol blue ✓ Acid X is a strong acid. KOH is a strong base. ✓ There is no hydrolysis of the salt produced, therefore the equivalence point of the titration would be within the range of indicator. ✓ Broomtimolblou Suur X is ʼn sterk suur. KOH is ʼn sterk basis. Daar is geen hidrolisereaksie van die sout wat vorm, dus sal ekwivalente punt van die titrasie binne die grense van die indikator wees. (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/JUNE/JUNIE 2021) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 15 7.2.5 c1V1=c2V2 0,049 x 15 ✓ = c2 x 90 ✓ c2 = 8,17 ×10-3 mol∙dm-3 nAcid/suur = cV ✓ = 8,17 ×10-x 25×10-3 ✓ = 2,04×10-4 mol caVa/cb.Vb = na/nb ✓ n(KOH) = 2 x 2,04×10-4 ✓ 8,17 ×10-3 x 25 ✓/ cb.28,5 ✓ = 4,08 x 10-4 mol =½✓ c = n/V cb = 0,014 mol∙dm-3 ✓ = 4,08 x 10-4/ 28,5 x 10-3 ✓ = 0,014 mol∙dm-3 ✓ (7) [26] TOTAL/TOTAAL: 150 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief