Physical Sciences Grade 12 P2 Eastern Cape June 2022 Memo

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE/ NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 12 JUNE/JUNIE 2022 PHYSICAL SCIENCES: CHEMISTRY P2 MARKING GUIDELINE/ FISIESE WETENSKAPPE: CHEMIE V2 NASIENRIGLYN MARKS/PUNTE: 150 This marking guideline consists of 13 pages./ Hierdie nasienriglyn bestaan uit 13 bladsye.

Downloaded from hlayiso.com 2 PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 (EC/JUNE/JUNIE 2022) QUESTION/VRAAG 1 1.1 A  (2) 1.2 B  (2) 1.3 A  (2) 1.4 C  (2) 1.5 B  (2) 1.6 D  (2) 1.7 B  (2) 1.8 A  (2) 1.9 B  (2) 1.10 D  (2) [20] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/JUNE/JUNIE 2022) PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 3 QUESTION/VRAAG 2 2.1 2.1.1 Alkyne  (1) 2.1.2 Haloalkane  (1) 2.2 2.2.1 E (1) 2.2.2 D (1) 2.3 2.3.1 Compound that contains carbon and hydrogen atoms only.  (2 or 0) Verbinding wat slegs koolstof- en waterstof-atome bevat. (2 of 0) (2) 2.3.2 UNSATURATED  Contains triple bond /multiple bonds (between the C-atoms in die hydrocarbon chain) ONVERSADIG Bevat ʼn drievoudige binding/ meervoudige bindings (tussen C-atome in die koolwaterstofketting) (2) 2.3.3 6-ethyl -2-methyl oct-4-yne  / 6-ethyl-2-methyl-4-octyne 6-etiel-2-metielokt-4-yne / 6-etiel-2-metiel-4-oktyn (3) 2.4 H O H Marking criteria/Nasienkriteria:  • Whole structure correct/Hele struktuur korrek: (2/2) H C C C H  • Only functional group correct Slegs funksionele groep korrek Max./Maks. (1/2) H H (2) 2.5 2.5.1 Butanal  (2) 2.5.2 Marking criteria/Nasienriglyne H H O • Whole structure correct/Hele struktuur korrek: (2/2) • Only functional group correct H C C C  Slegs funksionele groep korrek Max./Maks. (1/2) H H H C H H (2) 2.6 2.6.1 Combustion /Oxidation Verbranding / Oksidasie (1) 2.6.2 2 C6H14 + 19 O2  → 12 CO2 + 14 H2O  ( Balancing/ balansering) (3) 2.6.3 Compound A reacts exothermically with oxygen / releases heat when it reacts with oxygen.  Verbinding A reageer eksotermies met suurstof / hitte word vrygestel wanneer dit met suurstof reageer. (1) [22] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 4 PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 (EC/JUNE/JUNIE 2022) QUESTION/VRAAG 3 3.1 3.1.1 Boiling point is the temperature at which the vapour pressure of a liquid equals the atmospheric pressure.  Kookpunt is die temperatuur waarby die dampdruk van ʼn vloeistof gelyk is aan die atmosferiese druk. (2) 3.1.2 Functional group/ Homologous series/ Type of intermolecular forces. Funksionele groep / Homoloë reeks / Tipe intermolekulêrekragte. (1) 3.1.3 London forces /induced dipole forces/dispersion forces. Londonkragte/geЇnduseerde dipool kragte/verspreidingskragte. (1) 3.1.4 C has hydrogen bonds  (in addition to London forces) B has dipole-dipole forces (in addition to London forces) Hydrogen bonds are stronger than dipole dipole-forces  More energy is needed to overcome intermolecular forces in C  C het waterstofbinding (bykomend tot Londonkragte) B het dipool-dipoolkragte (bykomend tot Londonkragte) Waterstofbindings is sterker as die dipool-dipoolkragte Meer energie word benodig om die intermolekulêrekragte te oorkom in C OR/OF C has hydrogen bonds  (in addition to London forces) B has dipole-dipole forces (in addition to London forces) Dipole dipole forces are weaker than hydrogen bonds  Less energy is needed to overcome intermolecular forces in B  C het waterstofbinding (bykomend tot Londonkragte) B het dipool-dipoolkragte (bykomend tot Londonkragte) Dipool-dipool is swakker as die waterstofbindings Minder energie word benodig om die intermolekulêrekragte te oorkom in B (4) 3.2 3.2.1 Vapour pressure is the pressure exerted by a vapour  in equilibrium with its liquid in a closed container./  Dampdruk is die druk uitgeoefen deur ʼn damp in ewewig met sy vloeistof in ʼn geslote sisteem. (2) 3.2.2 p1 = 100 (kPa) /101,3 (kPa) / 1 atmosphere / atmosfeer (1) 3.2.3 Gas  A is above its boiling point / Bo A se kookpunt  (2) 3.2.4 LOWER THAN/LAER AS  (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/JUNE/JUNIE 2022) PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 5 3.2.5 Compound C only reached its boiling point at 117,7 °C where its vapour pressure will equal 101,3 kPa.  Verbinding C bereik eers sy kookpunt by 117,7 °C waar sy dampdruk eers gelyk aan 101,3 kPa gaan wees. (2) [16] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 6 PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 (EC/JUNE/JUNIE 2022) QUESTION/VRAAG 4 4.1 Substitution /Hydrolysis (of haloalkanes) Substitusie / Hidrolise (van haloalkane) (1) 4.2 CH3CH2CH2CH2OH  (2) 4.3 Primary alcohol  The carbon atom that contains the hydroxyl group (-OH) is bonded to one other carbon atom only.  Primêre alkohol Die koolstof-atoom wat die hidroksielgroep (-OH) bevat is verbind aan slegs een ander koolstof-atoom. (2) 4.4 Esterification/Condensation  Esterifikasie / Kondensasie (1) 4.5 Butyl ethanoate / Butiel-etanoaat  Marking criteria/Nasienkriteria: • Functional group/Funksionele groep.  (1/2) • Whole structure correct/ Hele struktuur korrek  (2/2) H H H H O H  H C C C C O C C H  H H H H H (4) 4.6 Dehydration / Dehidrasie  (1) 4.7 (concentrated / gekonsentreerde) H2SO4  (1) 4.8 Compounds with same molecular formula  but different positions of the functional group /side chains/substituent on the parent chain./ Verbindings met dieselfde molekulêre formule maar verskillende posisies van die funksionele groep/sykettings/substituent op die stamketting. (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/JUNE/JUNIE 2022) PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 7 4.9 H H Br H H C C C C H  + KOH/NaOH  → H H H H H H H H H C C C C H  + KBr/NaBr + H2O  H H Marking criteria/ Nasienkriteria Reactants / Reaktanse • Organic molecule correct/ Organiese molecule korrek  • KOH/NaOH  Products / Produkte • Organic molecule / Organiese molekule • Functional group/Funksionele groep.  (1/2) • Whole structure correct/ Hele struktuur korrek  (2/2) Inorganic products / Anorganiese produkte • KBr/NaBr  • H2O  (6) [20] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 8 PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 (EC/JUNE/JUNIE 2022) QUESTION 5/VRAAG 5 5.1 Change in concentration per unit time. /Amount of product formed/reactant used up per unit time. Verandering in konsentrasie per eenheid tyd / Hoeveelheid produk gevorm / reaktanse opgebruik per eenheidstyd. OR/OF Rate of change in concentration (2 or 0) Tempo van verandering in konsentrasie (2 of 0) (2) 5.2 Concentration  and a catalyst. / Konsentrasie en ʼn katalisator. (2) 5.3 5.3.1 Concentration (of H2O2) decreases / Konsentrasie (van H2O2) verlaag  (2) 5.3.2 t = 5 000(s)  (1) 5.3.3 Rate/tempo = - ∆c/∆t = - ( 1,0 – 0) /(0 – 5 000)  = 2 x 10 -4 mol·dm-3.s-1 (3) 5.3.4 ∆c = 0,8 mol·dm-3 n (H2O2) = cV = 0,8 x (0,15)  = 0,12 mol n (H2O2) = n (O2) = 0,12 mol  (Ratio / verhouding) n = V/Vm  0,12 = V/25 000  V = 3 000 cm3 /(3 dm3) (5) 5.4 5.4.1 Decrease / Verlaag  (1) 5.4.2 Remains the same / Bly dieselfde  (1) 5.5 5.5.1 Minimum energy required for a reaction to take place. / Minimum energie benodig vir ʼn reaksie om plaas te vind. (2) 5.5.2 Particles with sufficient kinetic energy to react. / Deeltjies met genoeg kinetiese energie om te reageer. (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/JUNE/JUNIE 2022) PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 9 5.5.3 E2  Calatyst lowers the activation energy  More particles have sufficient kinetic energy to react  More effective collisions per unit time /Frequency of effective collisions increases ʼn Katalisator verlaag die aktiveringsenergie. Meer deeltjies het genoeg kinetiese energie om te reageer Meer effektiewe botsings per eenheid tyd / Frekwensies van die effektiewe botsings neem toe (4) [24] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 10 PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 (EC/JUNE/JUNIE 2022) QUESTION 6/VRAAG 6 6.1 6.1.1 Reversible  (reaction) / Omkeerbare (reaksie) (1) 6.1.2 HIGHER THAN / HOËR AS  (2) 6.1.3 EQUAL TO / GELYK AAN  (1) 6.2 OPTION 1/ OPSIE 1 : MOLE OPTION / MOL OPSIE Marking Criteria/ Nasienkriteria: • Divide by 17 to calculate n(NH3)equilibrium.  Deel deur 17 om n(NH3)ewewig te bereken. • ∆n NH3  • Use mole ratio N2:H2: NH3 / Gebruik mol verhouding N2:H2: NH3  • n equilibrium / ewewig N2 and/en H2  • Divide 2 dm3 all n equilibrium / Deel deur 2 dm3 in alle newewig  • Correct Kc expression/Korrekte Kc uitdrukking.  • Substitution into Kc expression /Vervanging in Kc uitdrukking. • Final answer / Finale antwoord (0,41)  n (NH3) = m/M = 41,48/17  = 2,44 mol N2 3 H2 2 NH3 ni 4,88 6,18 0 ∆n 1,22 3,66 2,44  Ratio / verhouding ne 3,66 2,52  2,44  ce 1,83 1,26 1,22  (Div/by deel met 2 dm3) Kc = [NH3]2/[N2].[H2]3  = 1,222/1,83 x 1,263  = 0,41  Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/JUNE/JUNIE 2022) PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 11 OPTION 2: CONCENTRATION / OPSIE 2: KONSENTRASIE Marking criteria/ Nasienkriteria: • Calculate c (NH3)equilibrium.  Bereken c(NH3)ewewig • ∆c NH3  • ci N2 and/en H2  • Use conc. ratio N2:H2: NH3/Gebruik gekonsen. verhouding N2:H2: NH3  • c equilibrium /ewewig N2 and/en H2  • Correct Kc expression/Korrekte Kc uitdrukking.  • Substitution into Kc expression /Vervanging in Kc uitdrukking. • Final answer/Finale antwoord (0,41)  n (NH3) = m/M = 41,48/17 = 2,44 mol ce (NH3) = n/V = 2,44/2  = 1,22 mol·dm-3 ci (N2) = n/V = 4,88/2 = 2,44 mol·dm-3 ci (H2) = n/V = 6,18/2 = 3,09 mol·dm-3 N2 3 H2 2 NH3 ci 2,44 3,09 0 ∆c 0,61 1,83 1,22  Ratio / verhouding ce 1,83 1,26  1,22  Kc = [NH3]2/[N2].[H2]3  = 1,222/1.83 x 1,263  = 0,41  (8) 6.3 Temperature / Temperatuur  (1) 6.4 A At a given temperature the yield of NH3 is the highest  (in graph A) Increase pressure favours reaction which produces less gas moles  Forward reaction is favoured  By ʼn gegewe temperatuur is die opbrengs van NH3 die hoogste (in grafiek A) Toename in druk bevoordeel die reaksie wat die minste gas mol produseer Voorwaartse reaksie word bevoordeel (4) 6.5 6.5.1 Increase / Toeneem  (1) 6.5.2 No effect / Geen effek  (1) 6.5.3 Decrease/ Afneem  (1) [20] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 12 PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 (EC/JUNE/JUNIE 2022) QUESTION 7/VRAAG 7 7.1 7.1.1 An acid is a proton (H+-ion) donor  ʼn Suur is ʼn proton (H+-ioon) -skenker (2) 7.1.2 H2O  and / en H2SO4-  (2) 7.1.3 H2O or/of HSO4- (Any ONE / Enige EEN ) (1) 7.2 7.2.1 WEAK ACID  Low Ka value/ Ka < 1  SWAKSUUR Lae Ka-waarde / Ka < 1 (2) 7.2.2 H2SO4  (1) 7.2.3 pH = - log [H3O+]  Marking criteria/ Nasienkriteria • pH formula / formule 3 = - log [H3O+]  • Substitution / Substitusie • Ratio / Verhouding [H3O+] = 1 x 10-3 mol·dm-3 • Final answer / Finale antwoord [H2SO4] = ½ x 10-3  = 5 x 10 -4 mol.dm-3  (4) 7.2.4 CO32- + H2O  → HCO3- + OH- Na2CO3 + H2O → NaHCO3 + NaOH (Excess) OH- formed / (oormaat) OH- word geproduseer  (3) 7.3.1 It is a solution of known concentration  Dit is ʼn oplossing van bekende konsentrasie (2) 7.3.2 OPTION 1 / OPSIE 1: OPTION 2 / OPSIE 2: n = m/M n = 1,74/58  c = m/MV = 0,03 mol c = 1,74 / (58)(0,2)  c = n/V = 0,15 mol·dm-3 = 0,03 / 0,2  = 0,15 mol·dm-3 OPTION 3 / OPSIE 3: OPTION 4 / OPSIE 4: n = cV m = cMV = (0,15)(0,2)  = (0,15)(58)(0,2)  n = 0,3 mol m = 1,74 g m = nM = (0,3)(58)  = 1,74 g (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/JUNE/JUNIE 2022) PHYSICAL SCIENCES P2/FISIESE WENTESKAPPE V2 13 7.3.3 Marking guideline / Nasienriglyn • Calculating mole for Mg(OH)2 / Bereken mol vir Mg(OH)2 • Calculating the diluted concentration for HCl / Bereken die verdunde konsentrasie van HCl • Calculating the total mole for HCl / Bereken die totale mol van HCl • Calculating the reacted mole for HCl / Bereken die mol van HCl wat gereageer het • Determining the remaining mole for HCl / Bepaal die mol van HCl wat oorbly • Use of formula c = n/V in calculating the concentration of excess ions / Gebruik formule c = n/V om die konsentrasie van die oormaat ione te bereken • Substituting into / Vervanging in c = n/V • Final answer/ Finale antwoord n [Mg(OH)2] = cV = 0,15 x 0,04  = 0,006 mol c1V1 = c2V2 n = cV 5 x10 = c2(100)  OR/OF = (10)5 x 10-3 ) c2 = 0,5 mol·dm-3 n = 0,05 mol 𝑛 c=𝑉  0,05 = 0,1 c = 0,5 mol.dm-3 n (HCl) = cV = 0,5 x 0,05  = 0,025 mol n (HCl) reacting = 2 x 0,006  = 0,012 mol n (HCl) remaining = 0,025 – 0,012  = 0,013 mol c (HCl) = n/V = 0,013 / (0,09)  = 0,14 mol·dm-3  (9) [28] TOTAL/TOTAAL: 150 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief