Physical Sciences Grade 12 P2 Eastern Cape Mock 2022 Memo

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE/ NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 12 SEPTEMBER 2022 PHYSICAL SCIENCES P2 MARKING GUIDELINE/ FISIESE WETENSKAPPE V2 NASIENRIGLYN MARKS/ PUNTE: 150 This marking guideline consists of 19 pages./ Hierdie nasienriglyn bestaan uit 19 bladsye.

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

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 3 QUESTION/VRAAG 2 2.1 It is a series of organic compounds that can be described by the same general formula. ✓✓ (2 or 0) ʼn Reeks organiese verbindings wat deur dieselfde algemene formule beskryf kan word. (2 of 0) OR/OF A series/group of organic compounds in which one member differs from the next with -CH2- group. ✓✓ (2 or 0) ʼn Reeks organiese verbindings waarin die een lid van die volgende verskil met ʼn CH2-groep. (2) 2.2.1 D ✓ (1) 2.2.2 CnH2n-2 ✓ (1) 2.2.3 O Marking criteria/ Nasienkriteria H H ✓ • Only functional group correct / H C C C H ✓ Slegs funksionele groep korrek: H Max/ Maks ½ H C H • Whole structure correct/ H Hele struktuur korrek: 2/2 (2) 2.3 3-ethyl-2-methylhexanoic acid / 3-etiel-2-metielheksanoësuur Marking criteria • Correct stem i.e hexanoic acid ✓ • All substituents (ethyl and methyl) correctly identified ✓ • IUPAC name completely correct including numbering, sequence and hyphens ✓ Nasienkriteria • Korrekte stam d.i heksanoësuur • Alle substituente (etiel en metiel) korrek geїdentifiseer • IUPAC-naam heeltemal korrek insluitende nommering, volgorde en koppeltekens (3) 2.4.1 Marking criteria/Nasienkriteria H • Longest chain contains 3 carbons / H C H Langste koolstofketting bevat 3 koolstowwe ✓ H H • Two methyl substituents on C2 / H C C C H Twee metielsubstituente op C2 ✓ H • Whole structure is correct / Hele H struktuur korrek ✓ H C H H (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 4 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/SEPTEMBER 2022) 2.4.2 C5H12 + 8 O2 ✓→ 6 H2O + 5 CO2 ✓ (bal ✓) Marking criteria/ Nasienkriteria • Reactants / Reaktanse • Products / Produkte • Balancing / Balansering (3) [15] QUESTION/VRAAG 3 3.1.1 Marking criteria/Nasienkriteria If any of the underlined key words/phrases in the correct context are omitted: - 1 mark per word/phrase. Indien enige van die sleutelwoorde/frases in die korrekte konteks weggelaat word: - 1 punt per woord/frase. The temperature at which the vapour pressure of a liquid equals the atmospheric pressure. ✓✓ Die temperatuur waarby die dampdruk van die vloeistof gelyk is aan die atmosferiese druk. (2) 3.1.2 As the number of C atoms increases: • The surface area/chain length/molecular mass of the alcohols increases ✓ • The strength of London forces/induced dipole forces/dispersion forces increase. ✓ Soos die aantal C-atome toeneem: • Die oppervlak-area/kettinglengte/molekulêre massa van die alkohole verhoog. • Die sterkte van die Londonkragte/geїnduseerde dipoolkragte/ verspreidingskragte verhoog OR/OF As the number of C atoms decreases: • The surface area/chain length/molecular mass of the alcohols decreases ✓ • The strength of London forces/induced dipole forces/dispersion forces decrease. ✓ Soos die aantal C-atome afneem: • Die oppervlak-area/kettinglengte/molekulêre massa van die alkohole verlaag. • Die sterkte van die Londonkragte/geїnduseerde dipoolkragte/ verspreidingskragte verswak (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 5 3.1.3 Marking criteria • Identify the intermolecular forces in both compounds. ✓✓ • Compare the strength of the intermolecular forces. ✓ Nasienkriteria • Die intermolekulêre kragte korrek geїdentifiseer in beide verbindings • Vergelyk die sterkte van die intermolekulêre kragte • Alcohols have both (London forces) and hydrogen bonds ✓ • Ketones have both (London forces) and dipole-dipole forces ✓ • Hydrogen bonds in the alcohols are stronger than the dipole-dipole forces in ketones ✓ • Alkohole het beide (Londonkragte) en waterstofbindings • Ketone het beide (Londonkragte) en dipool-dipool kragte • Waterstofbindings in die alkohole is sterker as die dipool-dipoolkragte in ketone OR/OF • Alcohols have both (London forces) and hydrogen bonds ✓ • Ketones have both (London forces) and dipole-dipole forces ✓ • the dipole-dipole forces in Ketones are weaker than the hydrogen bonds in the alcohols ✓ • Alkohole het beide (Londonkragte) en waterstofbindings • Ketone het beide (Londonkragte) en dipool-dippol kragte • Die dipool-dipoolkragte in ketone is swakker as die waterstofbindings in die alkohole (3) 3.1.4 To have one independent variable✓ OR To have a fair test Om slegs een onafhanklike veranderlike te het OF Om ʼn regverdige toets te hê (1) 3.1.5 Ketone ✓ Lower boiling point / Laer kookpunt ✓ (2) 3.2.1 Propanoic acid / Propanoësuur ✓ (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 6 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/SEPTEMBER 2022) 3.2.2 Marking criteria • Identify the intermolecular forces correctly in both compounds. ✓ • Compare the strength of the intermolecular forces. ✓ • Compare the energy required to overcome the intermolecular forces. ✓ Nasienkriteria • Die intermolekulêre kragte is korrek in beide verbindings geїdentifiseer • Vergelyk die sterkte van die intermolekulêre kragte. • Vergelyk die energie wat benodig word om die intermolekulêre kragte te oorkom. • Both have hydrogen bonds • Propan-1-ol has ONE site for hydrogen bonds • Propanoic acid has TWO sites for hydrogen bonds ✓ • The intermolecular forces of propanoic acid are stronger than that of propan-1-ol ✓ • More energy is needed to overcome the intermolecular forces of propanoic acid. ✓ • Beide het waterstofbindings • Propan-1-ol het EEN plek vir waterstofbindings • Propanoësuur het TWEE plekke vir waterstofbindings • Die intermolekulêrekragte in propanoësuur is sterker as dié in propan-1-ol • Meer energie word benodig om die intermolekulêre kragte te oorkom in propanoësuur OR/OF • Both have hydrogen bonds. • Propan-1-ol has ONE site for hydrogen bonds ✓ • Propanoic acid has two sites for hydrogen bonds • The intermolecular forces of propan-1-ol are weaker than that of propanoic acid ✓ • Less energy is needed to overcome the intermolecular forces of propan-1-ol. ✓ • Beide het waterstofbindings • Propan-1-ol het EEN plek vir waterstofbindings • Propanoësuur het TWEE plekke vir waterstofbindings • Die intermolekulêrekragte in propan-1-ol is swakker as dié in propanoësuur. • Minder energie word benodig om die intermolekulêre kragte te oorkom in propan-1-ol. (3) [14] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 7 QUESTION/VRAAG 4 4.1.1 Esterification / condensation / Esterifikasie / konsensasie✓ (1) 4.1.2 (Mild) heat / (Matige) hitte ✓ (1) 4.1.3 H H H Marking criteria/ Nasienkriteria • Only functional group correct H C C C O H✓ ✓ Slegs funksionele groep korrek: Max/Maks ½ H H H • Whole structure correct/ Hele struktuur korrek: 2/2 (2) 4.1.4 Propyl ✓ethanoate ✓ / Propiel etanoaat (2) 4.1.5 Pentanoic acid / Propanoësuur ✓✓ (2) 4.1.6 Substitution reaction / Substitusie-reaksie ✓ (1) 4.1.7 H2O ✓ (1) 4.1.8 CH3CH2CH2Cℓ ✓✓ Marking criteria/ Nasienkriteria • Only functional group correct / Slegs funksionele groep korrek: Max/Maks ½ • Whole structure correct / Hele struktuur korrek: 2/2 (2) 4.2.1 (Concentrated / Gekonsentreerde) H2SO4 ✓ (2) 4.2.2 H2O in excess ✓ / catalyst/ (Add small amount of HCℓ/H3PO4) (1) 4.2.3 H H H H H H H C C C H✓ + H2O ✓ → H C C C H✓ ✓ ✓ H H H O✓ H H Marking criteria/ Nasienkriteria (Organic molecules / Organiese molekules) • Only functional group correct / Slegs funksionele groep korrek: Max/Maks ½ • Whole structure correct/ Hele struktuur korrek: 2/2 (5) [20] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 8 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/SEPTEMBER 2022) QUESTION/VRAAG 5 5.1 Marking criteria/ Nasienkriteria If any of the underlined key words/phrases in the correct context are omitted: - 1 mark per word/phrase. Indien enige van die sleutelwoorde/frases in die korrekte konteks weggelaat word: - 1 punt per woord/frase ANY ONE • Change in concentration ✓of reactant / product per (unit) time.✓ • Change in amount/number of moles/volume/mass of products or reactants per (unit) time. • Amount/number of moles/volume/mass of products formed/reactants used reactants per (unit) time. ENIGE EEN • Verandering in konsentrasie van reaktanse/produkte per (eenheid) tyd • Verandering in hoeveelheid/getal mol/volume/massa van reaktanse of produkte per (eenheid) tyd. • Hoeveelheid/getal mol/volume/massa van produkte gevorm/ reaktanse gebruik per (eenheid) tyd OR/OF The rate of change in concentration / amount of moles / number of moles / volume / mass. (2 or 0). Die tempo van verandering in konsentrasie / hoeveelheid mol / getal mol/volume/massa (2 of 0) (2) 5.2 Concentration / Konsentrasie (of/van HCℓ) ✓ (1) 5.3 Equal to / Gelyk aan ✓ The same amount of (the limiting reagent), Na2S2O3, is used. ✓ Dieselfde hoeveelheid (van beperkde reagens) Na2S2O3 was gebruik. (2) 5.4.1 Experiment 3 / Eksperiment 3 ✓ (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 9 5.4.2 For T2 • Higher temperature increases kinetic energy of particles ✓ • Greater number of particles have sufficient energy. ✓ • More effective collision per unit time ✓ Vir T2 • Hoër temperatuur verhoog die kinetiese energie van die deeltjies • Groter aantal deeltjies het genoeg energie • Meer effektiewe botsings per eenheidstyd OR/OF For T1 • Lower temperature decreases kinetic energy of particles • Fewer particles have sufficient energy. • Less effective collision per unit time Vir T1 • Laer temperatuur verlaag die kinetiese energie van die deeltjies • Minder aantal deeltjies het genoeg energie • Minder effektiewe botsings per eenheidstyd (3) Number of particles/ 5.4.3 Marking criteria/Nasienkriteria • X < Ea Aantal deeltjies ✓✓ X Ea Kinetic energy / Kinetiese energie (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 10 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/SEPTEMBER 2022) 5.5 Marking criteria • Formula n = m/M • Substitution into n = m/M • Using ratio HCℓ: Na2S2O3 2 : 1 • Substitution into rate equation • Final answer Nasienkriteria • Formule n = m/M • Vervanging in n = m/M • Gebruik van verhouding HCℓ: Na2S2O3 2 : 1 • Vervanging in tempo vergelyking • Finale antwoord m n= ✓ M 0,7118 n= ✓ 158 n (Na2S2O3) = 4,505 x 10-3 mol n (HCℓ) = 2 (4,505 x 10-3) ✓ n (HCℓ) = 9,01 x 10-3 mol Δn Accept / Aanvaar rate/ tempo = - Δt Δn 0 - 9,01 x 10-3 rate/ tempo = rate/ tempo = - ✓ Δt 34 - 9,01 x 10-3 rate/ tempo = 2,65 x 10-4 (mol·s-1) ✓ rate/tempo = 34 ✓ rate / tempo = - 2,65 x 10-4 (mol·s-1) ✓ (5) 5.6 REMAINS THE SAME / BLY DIESELFDE ✓ (1) [17] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 11 QUESTION/VRAAG 6 6.1.1 (A reaction in which) products can be converted back to its reactants ✓✓ (and vice versa) (Is ʼn reaksie waar) produkte terug na reaktanse, en omgekeerd, omgeskakel kan word. (2 or/ of 0) (2) 6.1.2 Turns more pink / Raak meer pienk ✓ (1) 6.1.3 Turns more blue / Raak meer blou ✓ (1) 6.1.4 Exothermic / Eksotermies ✓ (1) 6.1.5 • Increase in temperature shifted the equilibrium position left ✓/Reverse reaction is favoured • Increase in temperature favours the endothermic reaction ✓ • Toename in temperatuur verskuif die ewewigsposisie na links/ Terugwaartse reaksie word bevoordeel. • Toename in temperatuur bevoordeel ʼn endotermiese reaksie. (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 12 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/SEPTEMBER 2022) 6.2 OPTION 1: MOLE CALCULATIONS OPSIE 1: MOL BEREKENINGE Marking criteria: N a. Substitution into formula n = N ✓ A b. Using ratio N2O4 : NO2 = 1 : 2 ✓ c. n(NO2) equilibrium = n initial + Δn ✓ d. n(N2O4) equilibrium = n initial - Δn ✓ e. Divide equilibrium amounts of N2O4 and NO2 by 4 dm3 ✓ f. Correct KC expression (formulae in square brackets) ✓ g. Substitution into equilibrium concentration into KC expression ✓ h. Final answer ✓ Nasienkriteria: N a. Vervanging in formule n = N A b. Gebruik verhouding N2O4 : NO2 = 1 : 2 ✓ c. n(NO2) ewewig = n initial + Δn ✓ d. Deel ewewighoeveelhede van N2O4 en NO2 deur 4 dm3 e. Korrekte Kc-uitdrukking (formules met vierkanthakies) f. Vervanging in ewewigskonsentrasies in Kc-uitdrukking g. Finale antwoord N n= N A 3,01 × 1023 n= ✓ (a) 6,02×1023 n = 0,5 mol N2O4 (g) 2 NO2 (g) Initial quantity (mol) 0,5 - Aanvangshoeveelheid (mol) Change (mol) ✓ (b) 0,4 0,8 Verandering (mol) ratio Equilibrium (mol) 0,1 ✓ (d) 0,8 ✓ (c) Ewewig (mol) Concentration (mol·dm-3) ✓ (e) 0,025 0,2 Konsentrasie (mol·dm-3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 13 [NO2]2 No Kc expression, correct substitution / Geen Kc- Kc = ✓ (f) uitdrukking, korrekte, korrekte substitusie. [N2O4] Max / Maks 7/8 (0,2)2 Wrong Kc expression/Verkeerde Kc – uitdrukking. Kc = ✓ (g) (0,025) Max. Maks. 5/8 Kc = 1,6 ✓ (h) OPTION 2: CONCENTRATION CALCULATIONS/ OPSIE 2: KONSENTRASIEBEREKENINGE Marking criteria N a. Substitution into formula n = N ✓ A b. Using ratio N2O4: NO2 = 1 : 2 ✓ c. c(NO2) equilibrium = c initial + Δc ✓ d. c(N2O4) equilibrium = c initial – Δc ✓ e. Divide n initial and Δn of N2O4 by 4 dm3 ✓ f. Correct KC expression (formulae in square brackets) ✓ g. Substitution into equilibrium concentration into KC expression ✓ h. Final answer ✓ Nasienkriteria: N a. Vervanging in formule n = N A b. Gebruik verhouding N2O4 : NO2 1 : 2 c. Ewewig c(NO2) = begin c + Δc d. Ewewig c (N2O4) = begin c – Δc ✓(b) e. Deel aanvangs en verandering hoeveelhede van N2O4 en NO2 deur 4 dm3 f. Korrekte Kc-uitdrukking (formules met vierkanthakies) ✓ (e) g. Vervanging in ewewigskonsentrasies in Kc-uitdrukking h. Finale antwoord Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 14 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/SEPTEMBER 2022) N n= N A 3,01 × 1023 n= ✓ (a) 6,02 × 1023 n = 0,5 mol N2O4 (g) 2 NO2 (g) Initial concentration (mol·dm-3) 0,125 - Aanvangs konsentrasie (mol·dm-3) ✓ (d) Change in concentration (mol·dm-3) 0,1 0,2 Verandering in konsentrasie(mol·dm-3) Equilibrium concentration (mol·dm-3) 0,025✓ (c) 0,2 Ewewig konsentrasie (mol·dm-3) [NO2]2 No Kc expression, correct substitution / Geen Kc- Kc = ✓ (f) uitdrukking, korrekte substitusie. [N2O4] Max / Maks 7/8 (0,2)2 Wrong Kc expression / Verkeerde Kc -uitdrukking. Kc = ✓ (g) (0,025) Max. Maks. 5/8 Kc = 1,6 ✓ (h) (8) [15] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 15 QUESTION/VRAAG 7 7.1.1 An acid is a proton (H+ ion) donor / ʼn Suur is ‘n proton (H+-ioon) skenker ✓✓ (2) 7.1.2 HCℓ and/en Cℓ- ✓✓ OR/OF H3O+ and/en H2O ✓✓ (2) 7.1.3 Solution I. ✓ • HCℓ is a stronger acid than CH3COOH / HCℓ has a higher Ka ✓ (than CH3COOH) • HCℓ will produce a higher concentration of H3O+ ✓ (than CH3COOH) OR • CH3COOH is a weaker acid than HCℓ / CH3COOH has a lower Ka (than HCℓ) • CH3COOH will produce a lower concentration of H3O+ (than HCℓ) Oplossing I. • HCℓ is ʼn sterker suur as CH3COOH / HCℓ het ʼn hoër Ka-waarde as CH3COOH • HCℓ sal ʼn hoër konsentrasie van H3O+ produseer as CH3COOH OF • CH3COOH is ʼn swakker suur as HCℓ / CH3COOH het ʼn laer Ka-waarde as HCℓ • CH3COOH sal ʼn laer konsentrasie H3O+ produseer as HCℓ (3) 7.2.1 n = cV ✓ = 1 x10 / 1 000 ✓ = 0,01 mol ✓ (3) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 16 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/SEPTEMBER 2022) 7.2.2 Marking criteria Marking criteria • Formula pH = - log [H3O+] ✓ • Formula pOH + pH = 14 ✓ • pH value substituted into • pH value substituted into formula ✓ formula ✓ • Substitution in Kw formula✓ • Substitution in pOH formula✓ • Substitution into n = cV✓ • Substitution into n = cV✓ • Final answer✓ • Final answer✓ Nasienkriteria Nasienkriteria • Formule pOH + pH = 14 • Formule pH = - log [H3O+] • pH-waarde vervang in formule • pH-waarde vervang in formule • Vervanging in pOH formule • Vervanging in Kw formule • Vervanging in n = cV • Vervanging in n = cV • Finale antwoord • Finale antwoord OPTION 1 / OPSIE 1 OPTION 2 / OPSIE 2 pH = - log [H3O+] ✓ pOH + pH = 14 ✓ 13 ✓ = - log [H3O+] pOH + 13 ✓ = 14 [H3O+] = 1 × 10-13 mol·dm-3 pOH = 1 Kw = [OH-][H3O+] = 1 × 10-14 pOH = - log [OH-] [OH-][H3O+] = 1 × 10-14 1 = - log [OH-] ✓ [OH-](1 × 10-13) = 1 × 10-14 ✓ [OH-] = 0,1 mol·dm-3 [OH-] = 0,1 mol·dm-3 [NaOH] = 0,1 mol·dm-3 [NaOH] = 0,1 mol·dm-3 n OR/OF c = V c1V1 = c2V2 From 7.2.1 0,01 Vanaf 7.2.1 (1)(10) = (0,1)V2 ✓ 0,1 = ✓ V V2 = 100 cm3 V = 0,1 (dm3)✓ V = 0,1 (dm3) ✓ (5) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 17 7.2.3 Marking criteria Marking criteria / c V n • Formula n = cV✓ • Formula ca Va = na ✓ • Substitution of acid values into n = cV b b b c V AND • Substitution LHS ca Va ✓ ✓ n b b Using ratio Acid : Base = 1 : 2 • Substitution RHS na ✓ • Substitution of V and c into b n = cV for V base reacting ✓ • Subtracting Vremaining = Vinitial ‒ Vreacting ✓ • Subtracting Vremaining = Vinitial ‒ Vreacting ✓ • Final answer ✓ • Final answer ✓ Nasienkriteria Nasienkriteria c V n • Formule n = cV • Formule ca Va = na b b b • Vervanging van suur waardes in • c V Vervang LK ca Va b b formule n = cV n EN • Vervang RK na b Gebruik verhouding Suur : Basis = 1 : 2 • Aftrekking • Vervanging van V en c in n Voorbly = Vaanvangs – Vreageer = cV vir V basis wat reageer • Finale antwoord • Aftrekking Voorbly = Vaanvangs - Vreageer • Finale antwoord OPTION 1/OPSIE 1 OPTION 2/OPSIE 2 n acid reacting = cV✓ ca V a na = ✓ = 0,09 x 15/1 000 cb V b n b = 1,35 x 10-3 mol ✓ -3 n base reacting= 2 x 1,35 x 10 mol (0,09)(15) 1 = 2,7 x 10 -3 mol ✓= ✓ (0,1)Vb 2 n = cV Vb = 27 cm3 2,7 x 10 -3 = 0,1 Vbase reacting /basis reageer✓ Vb = 0,027 dm3 0,027 dm3 = Vbase reacting/ basis reageer Vremaining/oorbly = 0,1 – 0,027 ✓ = 0,073 dm3 ✓ (5) [20] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com 18 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/SEPTEMBER 2022) QUESTION/VRAAG 8 8.1 Loss of electrons / Verlies aan elektrone ✓✓ (2 or/of 0) (2) 8.2.1 1 mol·dm-3 ✓ (1) 8.2.2 Platinum ✓ (1) 8.2.3 Cu ✓ (1) 8.2.4 O2 + 4H+ + 4e- → 2 H2O ✓✓ Marking criteria / Nasienkriteria • O2 + 4H+ + 4e- ⇌ 2 H2O ½ • 2 H2O ← O2 + 4H + 4e + - 2/2 • 2 H2O ⇌ O2 + 4H + 4e + - 0/2 • 2 H2O → O2 + 4H+ + 4e- 0/2 • Ignore if the charge omitted on electron / Ignoreer indien lading op elektron weggelaat is. (2) 8.2.5 2 Cu + O2 + 4 H+ ✓→ 2 Cu2+ + 2 H2O ✓ (✓ bal) Marking criteria/Nasienkriteria • Reactants/ Reaktanse • Products / Produkte • Balancing / Balansering (3) 8.3.1 Eθcell = Eθcathode/reduction/oxidising agent – Eθanode/oxidation/reducing agent ✓ Notes/Aantekeninge Eθcell = (1,23) ✓ – (0,34) ✓ • Any other formula using unconventional abbreviation , e.g. Eθcell = 0,89 V ✓ Eocell = EoOA – Eo RA followed by the correct substitution : ¾ • Enige ander formule wat onkonvensionele afkortings gebruik bv. • Eosel = EoOM – Eo RM gevolg met korrekte vervangings: ¾ (4) 8.3.2 Concentration of the reactants decreases ✓ Rate of the forward reaction decreases ✓ Konsentrasie van reaktanse verlaag Tempo van voortwaartse reaksie verlaag (2) 8.3.3 Equilibrium / Ewewig ✓ (1) [17] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 19 QUESTION/VRAAG 9 9.1.1 Marking criteria/ Nasienriglyne If any of the underlined key words/phrases in the correct context are omitted: - 1 mark per word/phrase. Indien enige van die sleutelwoorde/frases in die korrekte konteks weggelaat word: - 1 punt per woord/frase (It is a cell in which) electrical energy ✓ is converted into chemical energy ✓ (Dit is ʼn sel waarin) elektriese energie omgeskakel word na chemiese energie. (2) 9.1.2 2 Cℓ- → Cℓ2(g) + 2e− ✓✓ Ignore phases / Ignoreer fases (2) Marking criteria / Nasienkriteria • 2 Cℓ- ⇌ Cℓ2(g) + 2e− ½ • Cℓ2(g) + 2e− ← 2 Cℓ- 2/2 • Cℓ2(g) + 2e− ⇌ 2 Cℓ- 0/2 Ignore if the charge omitted on electron / Ignoreer indien lading weggelaat is op elektron 9.1.3 H2 / Hydrogen gas / Waterstofgas (1) 9.1.4 H2O is a stronger oxidising agent than Na+ ✓ H2O is reduced to H2 ✓ H2O is ʼn sterker oksideermiddel as Na+ H2O word gereduseer na H2 (2) 9.2.1 Cathode / Katode ✓ (1) 9.2.2 nCu =½x6✓ Marking criteria = 3 mol • Use of ratio of electrons to Cu mCu = nM = 3 x 63,5✓ • Subst. into n = m/M • Division by 0,95 = 190,5 g • Final answer 0,95 ✓m IMPURE sample = 190,5 Nasienkriteria • Gebruik van verhouding van m IMPURE sample = 200,53 g ✓ elektrone tot Cu • Vervanging in n = m/M • Deel deur 0,95 • Finale antwoord (4) [12] TOTAL/TOTAAL: 150 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief