# Physical Sciences Grade 12 Paper 2 NSC November 2020 Memo

> Grade 12 Physical Sciences Paper 2 memorandum from the NSC November Exam 2020, 17 pages. Read online or download the free PDF.

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- Updated: 2026-09-27
- Subject: Physical Sciences
- Grade: Grade 12
- Document type: Memorandum
- Year: 2020
- Exam period: NSC November Exam
- Paper: 2
- Curriculum: CAPS
- Pages: 17

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             SENIOR CERTIFICATE/SENIOR SERTIFIKAAT
                 NATIONAL SENIOR CERTIFICATE/
                 NASIONALE SENIOR SERTIFIKAAT

                                   GRADE/GRAAD 12

                       PHYSICAL SCIENCES: CHEMISTRY (P2)
                       FISIESE WETENSKAPPE: CHEMIE (V2)

                                        NOVEMBER 2020

                      MARKING GUIDELINES/NASIENRIGLYNE

MARKS/PUNTE: 150

                     These marking guidelines consist of 17 pages./
                      Hierdie nasienriglyne bestaan uit 17 bladsye.

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Physical Sciences/P2/Fisiese Wetenskappe/V2      2                            DBE/November 2020
                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

QUESTION 1/VRAAG 1

1.1       C                                                                                     (2)

1.2       D                                                                                     (2)

1.3       C                                                                                     (2)

1.4       B                                                                                     (2)

1.5       D                                                                                     (2)

1.6       B                                                                                     (2)

1.7       B                                                                                     (2)

1.8       C                                                                                     (2)

1.9       A                                                                                     (2)

1.10      C                                                                                      (2)
                                                                                                  [20]

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                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

QUESTION 2/VRAAG 2

2.1.1     Ketones/Ketone                                                                                  (1)

2.1.2     Pentanal/Pentanaal                                   Marking criteria/Nasienriglyne
                                                                  Correct functional group,i.e. –
          ACCEPT/AANVAAR                                           al / Korrekte funksionele groep
          2,2-dimethylpropanal/2,2-dimethylpropanaal               d.i. al 
          2-methylbutanal/2-metielbutanaal                        Whole name correct/Hele
          3-methylbutanal/3-metielbutanaal                         naam korrek                            (2)

2.2.1     5 – bromo-2,3 – dimethylhexane/5 – bromo-2,3 – dimetielheksaan

          Marking criteria/Nasienriglyne:
           Correct stem i.e. hexane./Korrekte stam d.i. heksaan. 
           All substituents (bromo and dimethyl) correctly identified./Alle substituente (bromo
            en dimetiel) korrek geïdentifiseer. 
           IUPAC name completely correct including numbering, sequence, hyphens and
            commas./IUPAC-naam heeltemal korrek insluitende volgorde, koppeltekens en
            kommas .                                                                                      (3)

2.2.2         H     H                   H        Marking criteria/Nasienriglyne
                              
                                                 Whole structure correct/Hele struktuur
         H    C     C     C     C       C   H                                                   2
                                                       korrek:
                                                                                                    2
              H                         H         Only functional group correct:/Slegs
               H    C    H
                                                       funksionele groep korrek: Max/Maks.: 1
                                                                                                    2
                    H                            IF/INDIEN
                                                 More than one functional group/Meer as een
                                                 funksionele groep                             0
                                                                                                   2       (2)
          IF/INDIEN
          Molecular formula/Molekulêre formule 0
                                                   2
          Condensed structural formula /Gekondenseerde struktuurformule 1
                                                                                  2

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                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

2.3.1     The C atom bonded to the hydroxyl group is bonded to only one other
          C-atom.  (2 or 0)
          Die C-atoom wat aan die hidroksielgroep gebind is, is aan slegs een ander
          C-atoom gebind.(2 or 0)
          OR/OF
          The hydroxyl group/-OH/ is bonded to a C atom which is bonded to two
          hydrogens atoms. (2 or 0)
          Die hidroksielgroep/funksionele groep is gebind aan 'n C-atoom wat aan twee
          waterstofatome gebind is. (2 of 0)
          OR/OF
          The hydroxyl group/functional group/-OH is bonded to:
          a primary C atom / the first C atom (2 or 0)
          Die hidroksielgroep/funksionele groep/-OH aan
          'n primêre C-atoom gebind / die eerste C-atoom gebind (2 of 0)

          OR/OF
                                  |
          The functional group (─ C - OH) is bonded to only one other C-atom.
                                  |
                                    |
          Die funksionele groep (─ C – OH) is aan slegs een ander C-atoom gebind.
                                    |                                                                   (2)

2.3.2     Esterification/condensation 
          Verestering/esterifikasie/kondensasie                                                         (1)

2.3.3     Butanoic acid/Butanoësuur                                                                     (1)
                                                                                                        [12]

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                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

QUESTION 3/VRAAG 3
3.1       Marking criteria/Nasienriglyne
          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.

          The temperature at which the vapour pressure equals atmospheric (external)
          pressure. 
          Die temperatuur waar die dampdruk gelyk is aan atmosferiese (eksterne) druk.                  (2)
3.2          O

             C    H                                                                                    (1)

3.3        Increase in the number of C-atoms increases molecular mass/size/chain
            length/surface area. 
           Strength of the intermolecular forces increases/More sites for London
            forces. 
           More energy is needed to overcome/break intermolecular forces. 

           Toename in aantal C-atome verhoog molekulêre massa/molekulêre
            grootte/kettinglengte/reaksie-oppervlak.
           Sterkte van die intermolekulêre kragte verhoog./Meer punte vir
            Londonkragte.
           Meer energie benodig om intermolekulêre kragte te oorkom/breek.                             (3)
3.4.1     C                                                                                            (1)
3.4.2     B

          Marking criteria/Nasienriglyne
           Compare strength of intermolecular forces of A, B and C. 
           Compare boiling points/energy required to overcome intermolecular forces of
            alcohols/A and aldehydes/B. 
            OR
            Alcohols have the highest boiling point.
           Compare boiling points/ energy required to overcome intermolecular force of
            aldehydes/B and alkanes/C .
            OR
            Alkanes have the lowest boiling point.

           Vergelyk sterkte van intermolekulêre kragte van A, B en C. 
           Vergelyk kookpunte /energie benodig om intermolekulêre kragte van alkohole/A
            en aldehiede/B te oorkom. 
            OF
            Alkohole het die hoogste kookpunt.
           Vergelyk kookpunte /energie benodig om intermolekulêre kragte van aldehiede/B
            en alkane/C.
            OF
            Alkane het die laagste kookpunt.

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          Aldehydes/B have (in addition to London forces) dipole-dipole forces which
          are stronger than London forces, but weaker than hydrogen bonds. 
          Therefore aldehydes/B have lower boiling points/require less energy to
          overcome intermolecular forces than alcohols/A,but higher boiling points /
          require more energy to overcome intermolecular forces than alkanes/C. 

          Aldehiede/B het (in toevoeging tot Londonkragte) dipool-dipoolkragte wat
          sterker is as Londonkragte, maar swakker is as waterstofbinding.
          Dus het aldehiede/B laer kookpunte/benodig minder energie om
          intermolekulêre kragte te oorkom             as alkohole/A, maar hoër
          kookpunte/benodig meer energie om intermolekulêre kragte te oorkom as
          alkane/C.
          OR/OF
          Aldehydes/B have stronger intermolecular forces than alkanes, but weaker
          intermolecular forces than alcohols/A. 
          Therefore aldehydes/B have higher boiling points/ more energy required to
          overcome intermolecular forces than alkanes/C,  but lower boiling points/
          less energy to overcome intermolecular forces than alcohols/A. 

          Aldehiede/B het sterker intermolekulêre kragte as alkane/C, maar swakker
          intermolekulêre kragte as alkohole/A.
          Dus het aldehiede/B laer kookpunte/ benodig minder energie om
          intermolekulêre kragte te oorkom as alkohole/A, maar hoër kookpunte/
          benodig meer energie om intermolekulêre kragte te oorkom as alkane/C.                           (4)

3.5       Butanal                     Marking criteria/Nasienriglyne
          Butanaal                       Correct stem, i.e. but/Korrekte stam d.i. but 
                                         Whole name correct/Hele naam korrek                            (2)

3.6       Pentan-1-ol 
          OR/OF
          1-pentanol                                                                                     (2)
                                                                                                          [15]

QUESTION 4/VRAAG 4

4.1       Marking criteria/Nasienriglyne
           Addition reaction / reaction of alkene / reaction of C – C double bond /reaction of
            unsaturated hydrocarbon
            Addisie reaksie / reaksie van ‘n alkeen /reaksie van C – C dubbelbinding/reaksie
            van ‘n onversadigde koolwaterstof.
           (Addition of) hydrogen halide/HX/ hydrogen and halide. 
            (Addisie van) waterstofhalied/HX/waterstof en halied.

          The addition of a hydrogen halide/HX to an alkene.
          Die addisie van 'n waterstofhalied/HX aan 'n alkeen.                                            (2)

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                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

4.2            H          H                   Marking criteria/Nasienriglyne
                                               Whole structure correct:
          H    C     C     C       H                                                     2
                                                 Hele struktuur korrek:
                                                                                             2
               H     H                          Only functional group correct/Slegs funksionele
                                                 groep korrek:           Max/Maks: 1
                                                                                             2                   (2)

4.3.1    Cracking/Kraking                                                                                       (1)

4.3.2    C8H18                                                                                                  (1)

4.4      1,2–dibromo  propane 
         1,2-dibromopropaan/1,2-dibroompropaan                                                                   (2)

4.5.1         H     H     H                                      H       H       H
                                                                                               
                                           
         H    C     C     C    H + NaOH/H2O              H       C       C       C       H + NaCℓ/HCℓ
                                         /KOH                                                  /KCℓ
               H    Cℓ    H                                      H       O       H
                                                                                 
                                                                         H
         Marking criteria for the alcohol/Nasienriglyne vir die alkohol
           Whole structure of alcohol correct/Hele struktuur van alkohol korrek: 2
                                                                                                 2
           Only functional group correct/Slegs funksionele groep korrek: 1
                                                                                         2
         Notes/Aantekeninge:
            If 1-chloropropane used as reactant, 2 marks for the primary alcohol.
             Indien 1-chloropropaan as reaktanse gebruik is, 2 punte vir die primêre alkohol.
          Condensed or semi-structural formula: Max. 4
                                                                 5
              Gekondenseerde of semistruktuurformule: Maks. 4
                                                                     5
             Molecular formula/Molekulêre formule: 2
                                                         5
             Any additional reactants or products: Max. 4
                                                             5
              Enige addisionele reaktanse of produkte: Maks. 4
                                                                     5
             If arrow in completely correct equation omitted: Max. 4
                                                                             5
              Indien pyltjie in volledige korrekte vergelyking uitgelaat is: Maks. 4
                                                                                             5
             The product NaCℓ/KCℓ/HCℓ must be marked in conjunction with reactant
              NaOH/KOH/H2O.
              Die produk NaCℓ/KCℓ/HCℓ moet in samehang met die reaktans NaOH/KOH /
              H2O nagesien word.                                                                                 (5)

4.5.2         (Mild) heat/(Matige) hitte 
              Dilute strong base/NaOH/LiOH/KOH OR water/H2O 
               Verdunde sterk basis/NaOH/LiOH/KOH OF water/H2O                                                    (2)
                                                                                                                 [15]

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                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

QUESTION 5/VRAAG 5

5.1.1     (Reaction) rate/Reaksietempo                                                                 (1)

5.1.2     Surface area/state of division /particle size 
          Reaksie-oppervlak/toestand van verdeeldheid/deeltjie grootte                                  (1)

5.2.1     (Decreasing gradient indicates) rate of reaction is decreasing. 
          (Afnemende gradiënt dui aan dat) reaksietempo afneem.                                         (1)

5.2.2     (Gradient is zero, indicates) reaction rate is zero 
          (Gradiënt is nul, wat aandui dat) reaksietempo nul is.                                        (1)
5.3                                  V
          ave rate/gem tempo =
                                     t
                                     500 (  0)
                                 =               = 8,33 (cm3∙s-1) 
                                     60(  0)                                                          (3)
5.4       Equal to/Gelyk aan                                                                           (1)
5.5       Greater than/Groter as 
          Experiment C/Eksperiment C:
           Surface area of CaCO3 powder is greater than that of CaCO3 granules./
            More particles are exposed /More particles with correct orientation 
           More effective collisions per unit time/Higher frequency of effective
            collisions. 
           Increase in reaction rate.
           Reaksieoppervlak van CaCO3-poeier is groter (as die van CaCO3-korrels
            /Meer deeltjies met korrekte oriëntasie.
           Meer effektiewe botsings per eenheid tyd./Hoër frekwensie van effektiewe
            botsings
           Toename in reaksie tempo
          OR/OF
          Experiment A/Eksperiment A:
           Surface area of CaCO3 granules is smaller/Fewer particles are exposed
            (than that of powdered CaCO3). Less particles with correct orientation 
           Less effective collisions per unit time./Lower frequency of effective
            collisions. 
           Decrease in reaction rate..

           Reaksieoppervlak van CaCO3 is kleiner/Minder deeltjies is blootgestel (as
            die van die verpoeierde CaCO3)./ Minder deeltjies met korrekte oriëntasie
           Minder effektiewe botsings per eenheidtyd./Laer frekwensie van
            effektiewe botsings.
           Afname in reaksie tempo                                                                     (4)

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                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

5.6       Marking criteria/Nasienriglyne:
                                                                       V
             Divide volume by 25,7 in / Deel volume deur 25,7 in n =     .
                                                                      VM
              If no substitution step shown, award mark for answer: 0,0195 mol
              Indien geen vervanging stap getoon is nie, ken punt toe vit antwoord: 0,0195 mol
             Ratio/Verhouding: n(CO2) = n(CaCO3). 
                                              m
             Substitute/Vervang 100 in n =     or in ratio / of in verhouding. 
                                              M
             Final answer/Finale antwoord: 1,95 g to/tot 2 g. 
          OPTION 1/OPSIE 1                            OPTION 2/OPSIE 2
                    V     0,5                         25,7 dm3 .........1 mol
          n(CO2 )      =
                    Vm    25,7                       0,5 dm3 ..........0,0195 mol 
                  = 0,0195 mol                        100 g ...........1 mol
          n(CaCO3) = n(CO2) = 0,0195 mol             x ....................0,0195 mol 

          m(CaCO3) = nM                               x = m(CaCO3) = 1,95 g 
                     = 0,0195(100)
                     = 1,95 g 
          OPTION 3/OPSIE 3
                     V     0,5
          n(CO2 )      =       
                    Vm    25,7
                  = 0,0195 mol
          0,0195 mol CO2 ≡ 0,856 g CO2 
          m(CO2) produced : m(CaCO3)
          44 g              : 100 g 
          0,856             :x
          x = 1,95 g CaCO3                                                                                (4)
                                                                                                          [16]
QUESTION 6/VRAAG 6
6.1       Products can be converted back to reactants. 
          Produkte kan omgeskakel word na reaktanse.
          OR/OF
          Both forward and reverse reactions can take place.
          Beide voor-en terugwaartse reaksies kan plaasvind.
          OR/OF
          A reaction which can take place in both directions.
          ‘n Reaksie wat in beide rigtings kan plaasvind.                                                 (1)

6.2.1     Remains the same/Bly dieselfde                                                                 (1)

6.2.2     Increases/Toeneem                                                                              (1)

6.3          (When pressure is increased) the reaction that leads to the smaller
              amount of gas / side with less molecules/number of moles is favoured. 
              (Wanneer die druk verhoog word,) word die reaksie wat tot die kleiner
              hoeveelheid gas /minder gas molekule/aantal mol lei, bevoordeel.
             The reverse reaction is favoured. 
              Die terugwaartse reaksie word bevoordeel.                                                   (2)

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6.4      Endothermic/Endotermies 

           Kc decreases with decrease in temperature. 
           Reverse reaction is favoured. / Concentration of reactants increases. /
            Concentration of products decreases./Yield decreases 
           Decrease in temperature favours an exothermic reaction. 

           Kc neem af met afname in temperatuur.
           Terugwaartse reaksie word bevoordeel./Konsentrasie van reaktanse neem
            toe./Konsentrasie van produkte neem af./Opbrengs neem af
           Afname in temperatuur bevoordeel 'n eksotermiese reaksie.

         OR/OF
          Kc increases with increase in temperature. 
          Forward reaction is favoured. / Concentration of reactants decreases. /
           Concentration of products increases./Yield increases 
          Increase in temperature favours an endothermic reaction. 

           Kc neem toename met toename in temperatuur.
           Voorwaartse reaksie word bevoordeel./Konsentrasie van produkte neem
            toe./Konsentrasie van reaktanse neem af./Opbrengs neem toe
           Toename in temperatuur bevoordeel 'n endotermiese reaksie                                   (4)

6.5       CALCULATIONS USING NUMBER OF MOLES
          Mark allocation
           Correct Kc expression (formulae in square brackets). 
           Substitution of equilibrium concentrations into Kc expression. 
           Substitution of Kc value. 
           Multiply equilibrium concentrations of I2 and I by 12,3 dm3.  (OPTION 1)
           Multiply equilibrium concentrations of I by 12,3 dm3 and divide equilibrium mol of
            I2 by 12,3 dm3. (OPTION 2)
           Change in n(I) = n(I at equilibrium). 
           USING ratio/GEBRUIK verhouding: I2 : I = 1 : 2 
           Initial n(I2) = equilibrium n(I2) + change in n(I2). 
           Substitute 254 g·mol-1 as molar mass for I2.
           Final answer: (26 g - 27,94 g). 
          BEREKENINGE WAT AANTAL MOL GEBRUIK
          Puntetoekenning:
           Korrekte Kc-uitdrukking (formules in vierkanthakies).
           Vervanging van ewewigskonsentrasies in Kc-uitdrukking.
           Vervanging van Kc-waarde. 
           Vermenigvuldig ewewigskonsentrasies van I2 en I met 12,3 dm3.(OPSIE 1)
            Vermenigvuldig ewewigskonsentrasies van I met 12,3 dm3 en deel ewewigsmol I2
            met 12,3 dm3(OPSIE 2)
           Verandering in n(I) = n(I by ewewig)
           GEBRUIK verhouding: I2 : I = 1 : 2 
           Aanvanklike n(I2) = ewewigs n(I2) + verandering in n(I2).
           Vervang 254 g·mol-1 as molêre massa van I2.
           Finale antwoord: (26 g – 27,94 g)

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          OPTION 1/OPSIE 1
                 [ I] 2                      No Kc expression, correct substitution/Geen Kc-
          Kc           
                 [I 2 ]                      uitdrukking, korrekte substitusie: Max./Maks. 8
                                                                                             9
              
         3,76x10-3 =
                            
                      4,79  103  2
                                       Wrong Kc expression/Verkeerde Kc-uitdrukking:
                           I 2       Max./Maks. 6
          [I2] = 6,102 x 10 mol∙dm
                               -3   -3              9

                                                               I2                       I
           Initial mass (g)                             (0,1045)(254) 
           Aanvangsmassa (g)                             = 26,543 g 
           Initial quantity (mol)
                                                             0,1045                     0
           Aanvangshoeveelheid (mol)
           Change (mol)                                                                            Using
                                                             0,0295            0,0589 
           Verandering (mol)                                                                        ratio 
           Quantity at equilibrium (mol)/
                                                             0,0751             0,0589
           Hoeveelheid by ewewig (mol)
           Equilibrium concentration (mol∙dm-3)                                                     x12,3 
                                                         6,102 x 10-3         4,79 x 10-3
           Ewewigskonsentrasie (mol∙dm-3)

          OPTION 2/OPSIE 2
                                                                 I2             I
           Initial amount (moles)                                x              0
           Aanvangshoeveelheid (mol)
           Change in amount (moles)                                                              ratio 
                                                            0,0295          0,0589              verhouding
           Verandering in hoeveelheid (mol)
           Equilibrium amount (moles)
           hoeveelheid (mol)                                x - 0,0295    0,0589            
           Equilibrium concentration (mol∙dm-3)             x  0,0295                           x 12,3 and
                                                                                            -3
           Ewewigskonsentrasie (mol∙dm-3)                                 4,79 x 10              divide by
                                                               12,3                              12,3
                                            No Kc expression, correct substitution/Geen Kc-
               [ I] 2
          Kc                              uitdrukking, korrekte substitusie: Max./Maks. 8
               [I 2 ]                                                                       9

                   -3
          3,76x10 =
                     4,79  10   Wrong K expression/Verkeerde K -uitdrukking:
                                    3 2
                                                    c                               c

                             x  0,0295     Max./Maks. 6
                                                             9
                                12,3
                        x = 0,1045 mol

          m = nM            
                 = (0,1045)(254)
                 = 26,543 g 

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### Page 12

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Physical Sciences/P2/Fisiese Wetenskappe/V2     12                                       DBE/November 2020
                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

          CALCULATIONS USING CONCENTRATION
          Mark allocation
           Correct Kc expression (formulae in square brackets). 
           Substitution of equilibrium concentrations into Kc expression. 
           Substitution of Kc value 
           Change in n(I) = n(I at equilibrium). 
           USING ratio: I2 : I = 1 : 2 
           Initial [I2] = equilibrium [I2] + change in [I2]. 
           Divide by 12,3 dm3. 
           Substitute 254 g·mol-1 as molar mass for I2.
           Final answer 26,543 g. 
          BEREKENINGE WAT KONSENTRASIE GEBRUIK
          Puntetoekenning
           Korrekte Kc-uitdrukking (formules in vierkanthakies).
           Vervanging van ewewigskonsentrasies in Kc-uitdrukking.
           Vervanging van Kc-waarde.
           Verandering in n(I) = n(I by ewewig).
           GEBRUIK verhouding I2 : I = 1 : 2
           Aanvanklike [I2] = ewewigs [I2] + verandering in [I2].
           Deel deur 12,3 dm3. 
           Vervang 254 g·mol-1 as molêre massa van I2.
           Finale antwoord: 26,543 g

          OPTION 3/OPSIE 3
                 [ I] 2                             No Kc expression, correct substitution/Geen Kc-
          Kc           
                 [I 2 ]                             uitdrukking, korrekte substitusie: Max./Maks. 8
                                                                                                    9
                   -3
          3,76x10 =
                     4,79  10       3 2

                               I 2                Wrong Kc expression/Verkeerde Kc-uitdrukking:
                                                    Max./Maks. 6
          [I2] = 6,102 x 10-3 mol∙dm-3                           9

                                                                      I2                 I
                                               -3
           Initial concentration (mol∙dm )
           Aanvangskonsentrasie (mol∙dm-3)                        8,497x10-3             0
                                                                                                  Using
           Change (mol∙dm-3)
                                                                  2,395x10-3       4,79x10-3      ratio 
           Verandering (mol∙dm-3)
           Equilibrium concentration (mol∙dm-3)
                                                                6,102 x 10-3       4,79 x 10-3
           Ewewigskonsentrasie (mol∙dm-3)

              m
          c
              MV
                            m
          8,497  10 3 
                       (254)(12,3)
          m  26,546 g                                                                                         (9)
                                                                                                                [18]

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Physical Sciences/P2/Fisiese Wetenskappe/V2     13                               DBE/November 2020
                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

QUESTION 7/VRAAG 7

7.1.1       Weak/Swak 
        -
            Ionises/Dissociates incompletely/partially (in water) 
            Ioniseer/Dissosieer/onvolledig/gedeeltelik (in water)                                       (2)

7.1.2       OPTION 1/OPSIE 1                        OPTION 2/OPSIE 2
            pH = -log[H3O+]                        [H3O+] = 10-pH 
            3,85  = -log[H3O+]                            = 10-3,85 
            [H3O+] = 1,41 x 10-4 mol∙dm-3                 = 1,41 x 10-4 mol∙dm-3                      (3)
7.1.3       Greater than/Groter as                                                                     (1)
7.1.4       CH3COO-(aq) + H2O(ℓ)  ⇌ CH3COOH(aq) + OH-(aq) 
            OR/OF
            CH3COONa(aq) + H2O(ℓ)  ⇌ CH3COOH(aq) + NaOH(aq) 
            Due to formation of hydroxide/OH- / the solution is basic/alkaline /pH > 7. 
            As gevolg van die vorming van hidroksied/OH- is die oplossing basies/
            alkalies /pH > 7                                                                            (3)
7.2.1       Marking criteria/Nasienriglyne
                                                                       n c a  Va n a
               Substitute/vervang: 1 x 0,0145 OR/OF 1 x 14,5 in c =    /               
                                                                       V c b  Vb   nb .
               Use/Gebruik: n(CH3COOH) : n(NaOH) = 1:1 
               Final answer/Finale antwoord: 0,0145 mol 
            OPTION 1/OPSIE 1
            n(NaOH)reacted = cV
                           = 1(0,0145) 
                           = 0,0145 mol

            n(CH3COOH)diluted = n(NaOH) 
                              = 0,0145mol 
                                                                                                        (3)

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Physical Sciences/P2/Fisiese Wetenskappe/V2     14                               DBE/November 2020
                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

7.2.2    POSITIVE MARKING FROM 7.2.1./POSITEWE NASIEN VANAF VRAAG 7.2.1.
         Marking criteria/Nasienriglyne
          Calculate mass/Bereken massa CH3COOH in 25 cm3 (1,13 g). 
                                     m
             Formula/Formule: n =       .
                                     M
             Substitute/Vervang: M = 60 g∙mol-1. 
             n(CH3COOH)reacted/reageer = ninitial/begin - nunreacted/nie reageer 
             USE mol ratio/GEBRUIK molverhouding: n(CaCO3) : n(CH3COOH) = 1 : 2.
             Substitution of/Vervanging van 100 g∙mol-1 in m = nM. 
                                                                   0,217
             Calculate percentage/Bereken persentasie:                      100 
                                                                    1,2
             Final answer/Finale antwoord: 18,08%  (17,92 – 22,92)
                         4,52
         m(CH3COOH) =           25  = 1,13 g
                         100
                               m
         n(CH3COOH)ini/aanv. =    
                               M
                               1,13
                             =      = 0,01883 mol
                                60

         n(CH3COOH)rea = 0,01883 
                                 – 0,0145 = 0,0043 mol
                   1
         n(CaCO3) = n(CH3COOH)
                        2
                 = 0,5(0,0043) 
                 = 0,00217 mol
         m(CaCO3) = nM        
                  = 0,00217(100) = 0,217 g

                        0,217
         % CaCO3 =             100 
                         1,2
                      = 18,08 %                                                                         (8)
                                                                                                        [20]

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Physical Sciences/P2/Fisiese Wetenskappe/V2     15                                      DBE/November 2020
                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

QUESTION 8/VRAAG 8

8.1       Provides path for movement of ions./Ensures(electrical)neutrality in the cell. 
          Verskaf pad vir beweging van ione./Verseker (elektriese) neutraliteit in die sel.                    (1)

8.2       (The electrode) where oxidation takes place/electrons are lost. 
          (Die elektrode) waar oksidasie plaasvind/elektrone verloor word.                                     (2)

8.3       Mg/Magnesium                                                                                        (1)

8.4.1    2H++ 2e- → H2 

         Marking criteria/Nasienriglyne
         H2 ← 2H+ + 2e-              (2 )                     2H+ + 2e- ⇌ H2        (1 )
                                        2                                              2
         H2 ⇌ 2H + 2e +       -
                                      (0 )                       +
                                                              2H + 2e ← H2           (0 )
                                        2                                              2
             Ignore if charge omitted on electron./Ignoreer indien lading weggelaat op
              elektron.
             If charge (+) omitted on H+/Indien lading (+) weggelaat op H+:
                                                                                       Max./Maks: 1
                                                -
             Example/Voorbeeld: 2H+ 2e → H2 
                                                                                                       2       (2)

8.4.2    Magnesium/Mg                                                                                         (1)

8.5       OPTION 1/OPSIE 1                          Notes/Aantekeninge
            
          E cell     
                  E reduction     
                                E oxidation        Accept any other correct formula from the data
                                                      sheet./Aanvaar enige ander korrekte formule
                  0  ( 2,36)                     vanaf gegewensblad.
            
          E cell  2,36 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: 3
                                                                       4
         OPTION 2/OPSIE 2
             +    -
          2H + 2e → H2                                         E = 0 V 
             Mg(s)  Mg2+(aq) + 2e-                             E  = +2,36 V 
             Mg(s) + 2H+(aq)→ Mg2+(aq) + H2(g)                  E  = +2,36 V                                 (4)

8.6       H2 is a stronger reducing agent  than Cu  and therefore Cu2+/Cu ions are
          reduced/H2 is oxidised  Electrons flow from H2 to Cu.
          H2 is 'n sterker reduseermiddel as Cu en dus word Cu2+/Cu-ione
          gereduseer/H2 is geoksideer. Elektrone vloei vanaf H2 na Cu.                                          (3)
                                                                                                               [14]

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Physical Sciences/P2/Fisiese Wetenskappe/V2     16                                   DBE/November 2020
                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

QUESTION 9/VRAAG 9

9.1       ANY ONE/ENIGE EEN:
           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. (2 or 0)
           Decomposition of an ionic compound by means of electrical energy.
             (2 or 0)
           The process during which and electric current passes through a
             solution/ionic liquid/molten ionic compound. (2 or 0)

             Die chemiese proses waarin elektriese energie omgeskakel word na
              chemiese energie. (2 of 0)
             Die gebruik van elektriese energie om 'n chemiese verandering te weeg
              te bring. (2 of 0)
             Ontbinding van 'n ioniese verbinding met behulp van elektriese energie.
              (2 of 0)
             Die proses waardeur 'n elektriese stroom deur 'n oplossing/ioniese
              vloeistof/gesmelte ioniese verbinding beweeg. (2 of 0)                                      (2)

9.2       Battery/cell/ power source 
          Battery/sel/kragbron                                                                            (1)

9.3       Silver nitrate/AgNO3/ Silver ethanoate/CH3COOAg / Silver fluoride /AgF/
          Silver perchlorate AgCℓO4. 
          Silwernitraat/AgNO3/ Silweretanoaat/CH3COOAg / Silwerfloried / AgF /
          Silwerperchloraat / AgCℓO4                                                                      (1)

9.4       Remains the same/Bly dieselfde 
      -
          Rate of oxidation is equal to the rate of reduction. 
          Tempo van oksidasie is gelyk aan die tempo van reduksie.                                        (2)

9.5       Ag → Ag+ + e- 

          Notes/Aantekeninge
          Ag+ + e- ← Ag   (2 )                         Ag ⇌ Ag+ + e-      (1 )
                                  2                                           2
                    +
          Ag ← Ag + e    -
                             (0       )                Ag + e ⇌ Ag
                                                         +    -
                                                                           ( 0   )
                                  2                                            2
             Ignore if charge omitted on electron./Ignoreer indien lading weggelaat op
              elektron.
             If charge (+) omitted on Ag+/Indien lading (+) weggelaat op Ag+:
              Example/Voorbeeld: Ag → Ag + e-                                                          Max./Maks:
                                                                                                          (2)
                                                                                                          [8]

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Physical Sciences/P2/Fisiese Wetenskappe/V2     17                              DBE/November 2020
                           SC/NSC/SS/NSS – Marking Guidelines/Nasienriglyne

QUESTION 10/VRAAG 10

10.1.1    (Liquid) Air/(Vloeibare)Lug                                                              (1)

10.1.2    Natural gas/methane/oil/coal/coke
          Aardgas/metaan/olie/steenkool/kooks                                                       (1)

10.1.3    Iron/iron oxide/Fe/FeO 
          Yster/ysteroksied/Fe/FeO                                                                  (1)

10.1.4    NH3/Ammonia/Ammoniak                                                                     (1)

10.1.5    Ostwald (process)/Ostwald(proses)                                                        (1)

10.1.6    NH3 + HNO3  → NH4NO3                    Bal 

          Marking criteria/Nasienriglyne
           Reactants           Products          Balancing 
            Reaktanse            Produkte           Balansering
           Ignore double arrows./Ignoreer dubbelpyle.
           Marking rule 6.3.10./Nasienreël 6.3.10.                                                 (3)

10.2.1   NPK ratio/Ratio of primary nutrients 
         NPK-verhouding/Verhouding van primêre voedingstowwe                                        (1)

10.2.2    OPTION 1/OPSIE 1                      OPTION 2/OPSIE 2
          4  x X x 20  = 2,315 kg             m(P) = 2,315 kg
          9      100                                                  2,315
                                                Mass of 1 part P =          = 0,57575
                                                                        4
          X = 26  (26,04)
                                                Mass of N = (0,57575)(2) = 1,1575 kg
                                                Mass of K = (0,57575)(3) = 1,73625 kg

                                                Total mass of fertiliser:
                                                1,1575 + 2,315 + 1,73625 = 5,20875 kg 
                                                     5,20875
                                                X=           x 100 = 26,04 
                                                        20                                           (3)
                                                                                                    [12]

                                                                              TOTAL/TOTAAL:         150

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