# Physical Sciences Grade 12 Paper 2 NSC June 2018 Memo

> Grade 12 Physical Sciences Paper 2 memorandum from the NSC June Exam 2018, 15 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: 2018
- Exam period: NSC June Exam
- Paper: 2
- Curriculum: CAPS
- Pages: 15

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                  SENIOR CERTIFICATE EXAMINATIONS
                    SENIORSERTIFIKAAT-EKSAMEN

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

                                           2018

                      MARKING GUIDELINES/NASIENRIGLYNE

                                                                    MARKS/PUNTE: 150

                      These marking guidelines consist of 15 pages.
                       Hierdie nasienriglyne bestaan uit 15 bladsye.

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Physical Sciences P2/Fisiese Wetenskappe V2        2                                              DBE/2018
                                SCE/SSE – Marking Guidelines/Nasienriglyne

QUESTION 1/VRAAG 1

1.1      D                                                                                                    (2)
1.2      A                                                                                                    (2)
1.3      B                                                                                                    (2)
1.4      B                                                                                                    (2)
1.5      D                                                                                                    (2)
1.6      C                                                                                                    (2)
1.7      B                                                                                                    (2)
1.8      D                                                                                                    (2)
1.9      D                                                                                                    (2)
1.10     C                                                                                                    (2)
                                                                                                                [20]

QUESTION 2/VRAAG 2
2.1
2.1.1    A                                                                                                     (1)
2.1.2     D                                                                                                    (1)
2.1.3    B                                                                                                     (1)
2.1.4    E                                                                                                     (1)
2.1.5    B                                                                                                     (1)

2.2                                                      Marking criteria/Nasienriglyne
                                                        • Whole structure correct:
2.2.1            H               O       H
                                                           Hele struktuur korrek:                   2
         H       C       O       C       C       H                                                      2
                                                        • Only functional group correct:/Slegs
             H                           H                 funksionele groep korrek: Max/Maks.: 1
                                                                                                        2
          OR/OF
                                                         Accept/Aanvaar
                     H       H               O
                                                         Any correct arrangement of correct number of
             H                       O               H   atoms
                     C       C               C
                                                         Enige korrekte struktuur met die korrekte
                                                         aantal atome.
                     H       H                                                                                  (2)
2.2.2     ANY ONE/ENIGE EEN:
          Methyl ethanoate /metieletanoaat
          OR/OF
          Ethyl methanoate //etielmetanoaat                                                                   (2)

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                                 SCE/SSE – Marking Guidelines/Nasienriglyne

2.3
2.3.1     A large molecule composed of smaller monomer units covalently bonded to
          each other in a repeating pattern. 
          'n Groot molekuul wat uit kleiner monomeer-eenhede bestaan wat kovalent
          aan mekaar in 'n herhalende patroon gebind is.                                               (2)

2.3.2    Polyethene 
         Polieteen
         Accept/Aanvaar:
         Polyethylene/polythene
         Poli-eteen/poli-etileen/politeen                                                               (1)

2.3.3         H H                      H H                           H H
          n   C     C                   C   C          OR/OF     ...   C      C   ...

              H     H                   H   H     n                   H      H

         Accept as reactant/Aanvaar as reaktans:        Marking guidelines/Nasienriglyne
                                                        • Structure shows TWO C atoms with
           n CH2 CH2                                      four bonds (ethene) each and FOUR
                                                          H atoms./Struktuur toon TWEE C-
           n C2H4                                         atome met vier bindings (eteen) elk
                                                          na VIER H-atome. 
         Accept as product/Aanvaar as produk:
                                                        • Structure of product / Struktuur van
                                                          produk. 
                CH2 CH2
                             n                          • Multiple n and brackets correctly
                                                          shown for reactant and
                                                          product./Veelvoud n en hakie korrek
                                                          getoon vir reaktans en produk.               (3)

2.4       Hydrolysis/Substitution 
          Hidrolise/Substitusie                                                                         (1)

2.5       • Use concentrated strong base/NaOH/KOH/LiOH OR ethanolic/alcoholic
            strong base/NaOH/KOH/LiOH. /Use ethanol instead of water./No water.
            Gebruik gekonsentreerde sterk basis/NaOH/KOH/LiOH OF etanoliese /
            alkoholiese sterk basis/NaOH/KOH/LiOH /Gebruik etanol in plaas van
            water./Geen water nie.
          • Heat strongly/Verhit sterk 
            Accept/Aanvaar: Increase temperature/Verhoog temperatuur                                    (2)
                                                                                                        [18]

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                                 SCE/SSE – Marking Guidelines/Nasienriglyne

QUESTION 3/VRAAG 3

3.1       •   Structure/Struktuur:
              The chain length/molecular size /molecular structure/molecular mass/
              surface area increases. 
              Die kettinglengte/molekulêre grootte/molekulêre struktuur/molekulêre
              massa/oppervlakte neem toe.
         •    Intermolecular forces/Intermolekulêre kragte:
              Increase in strength of intermolecular forces/induced dipole /London/
              dispersion /Van der Waals forces/momentary dipoles. 
              Toename in sterkte van intermolekulêre kragte/geïnduseerde
              dipoolkragte/Londonkragte/dispersiekragte/Van der Waalskragte /
              momentele dipool.
          •   Energy/Energie:
               More energy needed to overcome/break intermolecular forces. 
               Meer energie benodig om intermolekulêre kragte te oorkom/breek.

         OR/OF
         •  Structure/Struktuur:
            From 4 C atoms to 1 C atom/bottom to top the chain length/molecular
            size/molecular structure/molecular mass/surface area decreases. 
            Van 4 C-atome na 1 C-atoom/onder na bo neem die kettinglengte/
            molekulêre grootte/molekulêre struktuur/molekulêre massa/oppervlakte
            af.
         •  Intermolecular forces/Intermolekulêre kragte:
            Decrease in strength of intermolecular forces/ induced dipole forces/
            London forces/dispersion forces. 
            Afname in sterkte van intermolekulêre kragte/geïnduseerde dipoolkragte/
            Londonkragte/dispersiekragte.
         •  Energy/Energie:
            Less energy needed to overcome/break intermolecular forces. 
            Minder energie benodig om intermolekulêre kragte te oorkom/breek.                           (3)

3.2       •    Alkanes have London/dispersion/induced dipole forces. 
               Alkane het London-/dispersie-/geïnduseerde dipoolkragte.
          •    Alcohols have hydrogen bonding (in addition to London/dispersion/
               induced dipole forces and dipole dipole forces). 
               Alkohole het waterstofbinding (in toevoeging tot London-/dispersie-/
               geïnduseerde dipoolkragte en dipoolkragte).
          •    Hydrogen bonding are stronger intermolecular forces than London/
               dispersion/ induced dipole forces. 
               Waterstofbindings is sterker intermolekulêre kragte as London-/dispersie-
               /geïnduseerde dipoolkragte.
               OR/OF
               More energy needed to overcome/break intermolecular forces in alcohols
               Meer energie benodig om intermolekulêre kragte te oorkom/breek in
               alkohole.
          •    Alcohols have higher boiling points than alkanes. 
               Alkohole het hoër kookpunte as die alkane.                                               (4)

3.3       Decrease/Neem af                                                                             (1)

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3.4         Lower than/Laer as 
        -
            2-methylpropane/It is more branched/has a smaller surface area/has a
            shorter chain length (than butane/chain isomer) 
            2-metielpropaan/Dit is vertak/het 'n kleiner oppervlakte/het 'n korter
            kettinglengte (as butaan/ketting-isomeer).

            OR/OF
            Butane/chain isomer is less branched /has larger surface area/longer chain
            length (than 2-methylpropane).
             Butaan/ketting-isomeer is minder vertak/het 'n groter oppervlakte/het 'n langer
             kettinglengte (as 2-metielpropaan).                                                        (2)
                                                                                                        [10]

QUESTION 4/VRAAG 4

4.1
4.1.1       Substitution/halogenation/bromonation
            Substitusie/halogenering/halogenasie/brominering/brominasie                                 (1)

4.1.2       Elimination/dehydration 
            Eliminasie/dehidrasie/dehidratering                                                         (1)

4.1.3       Esterification/condensation 
            Esterifikasie/verestering/kondensasie                                                       (1)

4.1.4       Addition/hydrohalogenation/hydrobromonation 
            Addisie/hidrohalogenasie/hidrohalogenering/hidrobrominasie/hidrobromonering                 (1)

4.2
4.2.1       Catalyst/dehydrating agent/speeds up reaction 
            Katalisator/dehidreermiddel/versnel die reaksie                                             (1)
4.2.2       Propyl  ethanoate /Propieletanoaat                                                        (2)

4.2.3                                            Marking criteria/Nasienriglyne:
                  H      O                        • Whole structure correct
                                                    Hele struktuur korrek:              2
              H    C     C   O   H                                                         2
                                                  • Only functional group correct
                   H                                                                     1
                                                    Slegs funksionele groep korrek:
                                                                                             2
            IF/INDIEN:
            More than one functional group/Meer as een funksionele groep                    0
                                                                                                2       (2)

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                                 SCE/SSE – Marking Guidelines/Nasienriglyne

4.3                 H     H     H                                   H      H      H
                                                                                      
              H    C     C      C H + HBr                      H   C      C      C    H + H2O 
                   H      H     O                                   H      H      Br
                                    
                               H
          Notes/Aantekeninge:
          • Ignore/Ignoreer ⇌
          • Accept HBr and H 2 O as condensed. /Aanvaar HBr en H 2 O as gekondenseerd.
          • Any additional reactants and/or products
                  Enige addisionele reaktanse en/of produkte:                    Max./Maks. 4
                                                                                                5
          •       Accept coefficients that are multiples.
                  Aanvaar koëffisiënte wat veelvoude is.
          •       Incorrect balancing/Verkeerde balansering:                     Max./Maks. 4
                                                                                                5
          •       Molecular/condensed formulae
                  Molekulêre/gekondenseerde formule:                             Max./Maks. 2
                                                                                                5             (5)
                                                                                                              [14]

QUESTION 5/VRAAG 5

5.1       ONLY ANY ONE OF/SLEGS ENIGE EEN VAN:
          • Change in concentration of products/reactants  per (unit) time. 
            Verandering in konsentrasie van produkte/reaktanse per (eenheids)tyd.
          •       Rate of change in concentration. 
                  Tempo van verandering in konsentrasie.
          •       Change in amount/number of moles/volume/mass  of products or
                  reactants per (unit) time. 
                  Verandering in hoeveelheid/aantal mol/volume/massa van produkte of
                  reaktanse per (eenheids)tyd.
          •       Amount/number of moles/volume/mass (of products) formed/(reactants)
                  used per (unit) time.
                  Hoeveelheid/aantal mol/volume/massa (van produkte) gevorm/(reaktanse)
                  gebruik per (eenheids)tyd.                                                                  (2)

5.2
5.2.1     Surface area/State of division 
          Oppervlakte/Toestand van verdeeldheid                                                               (1)

5.2.2     ANY ONE/ENIGE EEN:
          • Amount/mass of magnesium 
            Hoeveelheid/massa magnesium
          • Concentration of HCℓ/acid/Konsentrasie van HCℓ /suur
          • (Initial) temperature/(Aanvanklike) temperatuur                                                   (1)

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                                 SCE/SSE – Marking Guidelines/Nasienriglyne

5.3
5.3.1     Marking criteria/Nasienriglyne
          • Calculate change in m(Mg) or n(Mg) 
            Bereken verandering in m(Mg) of n(Mg)
                                                     m
          •   Substitute/Vervang 24 g∙mol-1 in n =     
                                                     M
          •   Use mol ratio/Gebruik molverhouding: n(Mg) = n(H 2 ) = 1:1 
                                                 V
          •   Substitute/Vervang 25 dm3 in n =      .
                                                 Vm
          •   Final answer/Finale antwoord: 2,5 dm3 

          OPTION 1/OPSIE 1                               OPTION 2/OPSIE 2
          △m(Mg) = 2,6 - 0,2                                          m   2,6
                                                         n(Mg) t =2s =   =     = 0,1083 mol
                    = 2,4 g                                            M   24 
                                m
          n(Mgused /gebruik ) =                                            0,2
                                M                        n(Mg) t =10 s =       = 0,0083 mol
                                2,4                                        24
                             =
                                24                      △n(Mg) = 0,1083 - 0,0083 
                             = 0,1 mol                          = 0,1 mol

          n(H 2 ) = n(Mg) = 0,1 mol                     n(H 2 ) = n(Mg) = 0,1 mol 

          V(H 2 ) = nV m                                 V(H 2 ) = nV m
          V(H 2 ) = (0,1)(25)                           V(H 2 ) = (0,1)(25) 
                  = 2,5 dm3                                     = 2,5 dm3 
          OPTION 3/OPSIE 3
          24 g Mg          25 dm3 H 2
          ∴ 2,4 g          x dm3 H 2
              2,4 × 25 
          x=              
                   24
            = 2,5 dm3                                                                                     (5)

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                                 SCE/SSE – Marking Guidelines/Nasienriglyne

5.3.2     Marking criteria/Nasienriglyne
                                                                          ∆n
          •   Substitute/Vervang 2,08 x 10-4 in ave rate / gem. tempo =        
                                                                          ∆t
                                                                                   ∆n
          •   Substitute/Vervang 10 x 60 s (600 s) in ave rate / gem. tempo =           
                                                                                   ∆t
          • Use mol ratio/Gebruik molverhouding: n(Mg) = n(H 2 ) = 1:1 
          • Substitute/Vervang 24 g∙mol-1 in m = nM. 
          • Final answer/Finale antwoord: 3 g  (Range/Gebied 2,995 – 3,12 g)
                                        ∆n
          ave rate / gem. tempo =
                                        ∆t
                             ∆n
          ∴ 2,08 x 10-4 =
                        (10 × 60) − 0 
          ∴ △n = 0,125 mol

          n(Mg) = n(H 2 ) = 0,125 mol 

          m(Mg) = nM
          m(Mg) = 0,125 x 24 
                = 3 g  (2,995 g)                                                                       (5)

5.4       •   Larger surface area/state of division. 
              Groter reaksieoppervlak/toestand van verdeeldheid
          •   More particles (per volume) with correct orientation/Meer deeltjies (per
              volume) met korrekte oriëntasie. 
              OR/OF
              More contact points./Meer kontakpunte.
          •   More effective collisions per (unit) time./Frequency of effective collisions
              increases./More particles collide with sufficient kinetic energy & correct
              orientation per (unit) time.
              Meer effektiewe botsings per (eenheids)tyd./Frekwensie van effektiewe
              botsings verhoog./Meer deeltjies bots met genoeg kinetiese energie &
              korrekte oriëntasie per tyd(seenheid).                                                    (3)
                                                                                                        [17]

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QUESTION 6/VRAAG 6

6.1       The stage in a chemical reaction when the rate of forward reaction equals the
          rate of reverse reaction./Both forward and reverse reactions take place at
          same rate. 
          Die stadium in 'n chemiese reaksie wanneer die tempo van die voorwaartse
          reaksie gelyk is aan die tempo van die terugwaartse reaksie./Beide voor- en
          terugwaartse reaksies vind teen dieselfde tempo plaas.
          OR/OF
          The stage in a chemical reaction when the concentrations of reactants and
          products remain constant. 
          Die stadium in 'n chemiese reaksie wanneer die konsentrasies van reaktanse
          en produkte konstant bly.                                                                     (2)
6.2
6.2.1     2                                                                                            (1)
6.2.2     1                                                                                            (1)
6.2.3     3                                                                                            (1)
6.3       POSITIVE MARKING FROM QUESTION 6.2.
          POSITIEWE NASIEN VANAF VRAAG 6.2.
          Marking criteria/Nasienriglyne:
                                                 n
          •    Substitute/Vervang 8 mol in c =       
                                                 V
                                                 n
          •    Substitute/Vervang 4 mol in c =       
                                                 V
                                                  n
          •    Substitute/Vervang 12 mol in c = 
                                                  V
          •    Substitute/Vervang V = 3 dm3 in the above THREE formulae/in die bostaande
               DRIE formules. 
          •    K c expression/uitdrukking 
          •    Substitution of concentrations into K c expression 
               Vervanging van konsentrasies in K c -uitdrukking.
          •    Final answer/Finale antwoord: 6,75 

          OPTION 1/OPSIE 1
                8
          [A] =    = 2,67 mol∙dm-3
                3
                4
          [B] =    = 1,33 mol∙dm-3       Divide by/Deel deur 3 dm3 
                3
                12 
          [C] =     = 4 mol∙dm-3
                 3
                                         No Kc expression, correct substitution /Geen Kc-
                 [C]3                    uitdrukking, korrekte substitusie: Max./Maks. 6
          Kc =                                                                          7
               [ A ] 2 [B]
                       ( 4 )3            Wrong Kc expression /Verkeerde Kc-uitdrukking:
             =                  
               (2,67)2 (1,33)            Max./Maks. 4
                                                      7
             = 6,75 

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           OPTION 2/OPSIE 2
                                                            A          B           C
           Initial quantity (mol)
                                                            16          8          0
           Aanvangshoeveelheid (mol)
           Change (mol)
                                                            8           4         12
           Verandering (mol)
           Quantity at equilibrium (mol)
                                                           8         4          12 
           Hoeveelheid by ewewig (mol)
           Equilibrium concentration (mol∙dm-3)             8           4         12      Divide by
           Ewewigskonsentrasie (mol∙dm-3)                                                 /deel deur
                                                            3           3          3      3 dm3 

                  [C]3                  No Kc expression, correct substitution /Geen Kc-
           Kc =               
                [ A ] 2 [B]
                                        uitdrukking, korrekte substitusie: Max./Maks. 6
                        ( 4 )3                                                          7
              =                 
                (2,67)2 (1,33)          Wrong Kc expression /Verkeerde Kc-uitdrukking:
              = 6,75                   Max./Maks. 4
                                                     7
                                                                                                            (7)

           USING CONCENTRATION/GEBRUIK KONSENTRASIE
           OPTION 3/OPSIE 3
                                                             A                B             C
                                          -3
           Initial concentration (mol∙dm )               16               8
           Aanvangskonsentrasie (mol∙dm-3)                   = 5,33         = 2,67          0
                                                          3               3
           Change (mol∙dm-3)                              8               4               12            3
           Verandering (mol∙dm-3)                           = 2,67          = 1,33            =4
                                                          3               3                3           dm3 
           Equilibrium concentration (mol∙dm-3)          8               4               12
           Ewewigskonsentrasie (mol∙dm-3)                  = 2,67         = 1,33           = 4
                                                         3               3                3

                  [C]3
           Kc =               
                [ A ] 2 [B]                    No Kc expression, correct substitution /Geen Kc-
                        ( 4 )3                 uitdrukking, korrekte substitusie: Max./Maks. 6
              =                                                                                7
                (2,67)2 (1,33)
              = 6,75                          Wrong Kc expression /Verkeerde Kc-uitdrukking:
                                               Max./Maks. 4
                                                            7
                                                                                                            (7)

6.4        Endothermic/Endotermies 
       -
           • (An increase in temperature) favours the reverse reaction. 
             ('n Toename in temperatuur )bevoordeel die terugwaartse reaksie.
           • An increase in temperature favours an endothermic reaction. 
             'n Toename in temperatuur bevoordeel 'n endotermiese reaksie.                                  (3)
                                                                                                            [15]

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                                 SCE/SSE – Marking Guidelines/Nasienriglyne

QUESTION 7/VRAAG 7

7.1      Titration/Volumetric analysis 
         Titrasie/Volumetriese analise                                                                  (1)

7.2      To measure the (exact) volume of acid needed to reach endpoint/to neutralise
         the base. 
         Om die (presiese) volume suur te meet wat benodig word om die eindpunt te
         bereik/om die basis te neutraliseer.                                                           (1)

7.3      Acids produce hydrogen ions (H+)/hydronium ions (H 3 O+) in solution/when
         dissolved in water. 
         Sure vorm waterstofione(H+)/hidroniumione (H 3 O+) in oplossing/wanneer
         opgelos in water.

         IF/INDIEN:
         Acids produce hydrogen ions (H+)/hydronium ions (H 3 O+). 
         Sure vorm waterstofione(H+)/hidroniumione (H 3 O+).                                            (2)

7.4      H 2 SO 4 ionises completely./ H 2 SO 4 ioniseer volledig.                                     (1)

7.5      Blue to yellow/Blou na geel                                                                   (1)

7.6      Marking guidelines/Nasienriglyne:
                                    n         c × Va n a
          • Formula/Formule: c =      /n = cV/ a      =    
                                    V         c b × Vb n b
          • Substitution of/Vervanging van: (0,1)(25)/(0,1)(0,025) 
          • Use mol ratio/Gebruik molverhouding: n a : n b = 1 : 2 
          • Final answer/Finale antwoord: 12,5 cm3 / 0,0125 dm3 

         OPTION 1/OPSIE 1                         OPTION 2/OPSIE 2
         c a Va na                                      n
               =                                 cb =     
         c b Vb nb                                      V
                                                           n
                                                  0,1 =         
           (0,1 )Va  1                                   0,025
                    = 
          (0,1)(25) 2                            n b = 2,5 x 10-3 mol
         ∴ V a = 12,5 cm3                              1        1
                                                  na =     nb =      (2,5 x 10-3) 
                                                        2        2
                                                              = 1,25 x 10-3 mol
                                                        n
                                                  ca =
                                                        V
                                                         1,25 × 10 −3
                                                  0,1 =
                                                              V
                                                  ∴ V a = 0,0125 dm3 /12,5 cm3                         (4)

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Physical Sciences P2/Fisiese Wetenskappe V2        12                                                  DBE/2018
                                 SCE/SSE – Marking Guidelines/Nasienriglyne

7.7      POSITIVE MARKING FROM QUESTION 7.6.
         POSITIEWE NASIEN VANAF VRAAG 7.6.
         Marking guidelines/Nasienriglyne:
                                     n
          • Formula/Formule: c =       
                                     V
          •   Substitution of/Vervanging van: (0,1)(0,005)/0,0175 in n = cV 
          •   Substitute/Vervang V = 0,0425 dm3 
          •   Use/Gebruik [H 3 O+] : [H 2 SO 4 ] = 2 : 1 
          •   Formula/Formule: pH = -log[H 3 O+] 
          •   Substitute/Vervang [H+] 
          •   Final answer/Finale antwoord: 1,63 
         OPTION 1/OPSIE 1                           OPTION 2/OPSIE 2
         n a(excess/oormaat) = cV                  n a(final/finaal) = cV 
                             = (0,1)(0,005)                          = (0,1)(0,0175) 
                            = 5 x 10-4 mol                            = 1,75 x 10-3 mol
                  n                                 n a(exs/oor) = n a(final/finaal) - n a(react/reageer)
         ca =                                                    = 1,75 x 10-3 – 1,25 x 10-3
                  V
                                                                 = 5 x 10-4 mol
                  5 × 10 −4
              =
                4,25 × 10 −2                               n
                                                    ca =
              = 1,18 x 10-2 mol·dm-3                        V
         c(H+) = 2c a                                       5 × 10 −4
                                                        =
               = 2(1,18 x 10-2)                          4,25 × 10 −2 
               = 2,36 x 10-2 mol·dm-3                   = 1,18 x 10-2 mol·dm-3
         pH = -log[H 3 O+]                         c(H+) = 2c a
            = -log(2,36 x 10-2)                          = 2(1,18 x 10-2) 
            = 1,63                                       = 2,36 x 10-2 mol·dm-3
                                                    pH = -log[H 3 O+] 
                                                       = -log (2,36 x 10-2) 
                                                       = 1,63                                                    (7)
         OPTION 3/OPSIE 3
         n a(excess/oormaat) = cV 
                             = (0,1)(0,005) 
                             = 5 x 10-4 mol
              +
         n(H ) = 2n a(excess/oormaat)
                 = 2(5 x 10-4) 
                 = 1 x 10-3 mol
                     n
         c(H+) =
                     V
                     1× 10 −3
                =
                   4,25 × 10 −2
                = 2,36 x 10-2 mol·dm-3

         pH = -log[H 3 O+] 
            = -log (2,36 x 10-2) 
            = 1,63 
                                                                                                                  [17]
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Physical Sciences P2/Fisiese Wetenskappe V2        13                                             DBE/2018
                                 SCE/SSE – Marking Guidelines/Nasienriglyne

QUESTION 8/VRAAG 8

8.1
8.1.1     Galvanic (cell)/Voltaic (cell) 
          Galvaniese (sel)/Voltaïese (sel)                                                                     (1)
8.1.2     Indicates phase boundary./Interphase /phase separator
          Dui faseskeiding aan/Interfase /fase onderskeier                                                     (1)
8.1.3     Fe2+ → Fe3+ + e- 

          Notes/Aantekeninge
          •   Fe3+ + e- ← Fe2+       (2 )           Fe3+ + e- ⇌ Fe2+   (0 )
                                         2                                 2
               Fe ⇌ Fe + e
                   2+      3+    -
                                      ( 1  )          3+    -
                                                    Fe + e → Fe   2+
                                                                        ( 0   )
                                         2                                  2
          •    Ignore if charge on electron is omitted./Ignoreer indien lading op elektron
               uitgelaat is.
          •    If a charge of an ion is omitted e.g. Fe2 → Fe3 + e-/Indien lading op ioon
               uitgelaat is bv. Fe2 → Fe3 + e-    Max./Maks: 1                                                 (2)
                                                               2

8.1.4    OPTION/OPSIE 1                         Notes/Aantekeninge
           θ
         E cell     θ
                = E reduction     θ
                              − E oxidation    • Accept any other correct formula from the data
                                                  sheet./Aanvaar enige ander korrekte formule
         0,03  = EθX / X2+ - (0,77)             vanaf gegewensblad.
          EθX / X2+ = 0,80 (V)                 • Any other formula using unconventional
                                                  abbreviations, e.g. Eθ cell = Eθ OA - Eθ RA followed by
                                                  correct substitutions:/Enige ander formule wat
         X = Silver / Ag                         onkonvensionele afkortings gebruik bv.
                                                  Eθ sel = Eθ OM - Eθ RM gevolg deur korrekte
                                                  vervangings: Max/Maks: 4
                                                                                 5
         OPTION/OPSIE 2

          X+(aq) + e-  X(s)                                0,80 (V) 
           Fe2+(s)  Fe3+(aq) + e-                           0,77 (V) 
           X+(aq) + Fe2+(aq)  X(s) +Fe3+(aq)                0,03 (V) 

         X = Silver/Ag/Silwer                                                                                 (5)

8.2
8.2.1     Pt                                                                                                  (1)
8.2.2     Iron(III) (ions)Ferric ions
          Yster(III)-(ione)/Ferri ione                                                                         (1)

8.2.3     2Fe3+ + Cu → 2Fe2+ + Cu2+                        Bal. 
          Notes/Aantekeninge
          •   Reactants         Products         Balancing 
              Reaktanse          Produkte          Balansering
          • Ignore phases./Ignoreer fases.
          •   Ignore double arrows./Ignoreer dubbelpyle.
          •   Marking rule 6.3.10/Nasienreël 6.3.10.                                                           (3)
                                                                                                               [14]

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Physical Sciences P2/Fisiese Wetenskappe V2        14                                     DBE/2018
                                 SCE/SSE – Marking Guidelines/Nasienriglyne

QUESTION 9/VRAAG 9

9.1
9.1.1       Electrolyte/Elektroliet                                                                    (1)

9.1.2       Conduct electricity/Carry charges 
            Gelei elektrisiteit/Dra ladings.                                                            (1)

9.2         Cu(NO 3 ) 2                                                                                (1)

9.3         Iron rod/Ysterstaaf 
        -
            Reduction takes place./Reduksie vind plaas.                                                (2)

9.4         Cu → Cu2+ + 2e- 

            Notes/Aantekeninge
            • Cu2+ + 2e- ← Cu         (2 )                  Cu2+ + 2e- ⇌ Cu    (0 )
                                          2                                        2
                          2+
                Cu ⇌ Cu + 2e     -
                                      ( 1   )                  2+
                                                            Cu + 2e → Cu        ( 0   )
                                         2                                          2
            •   Ignore if charge on electron is omitted./Ignoreer indien lading op elektron
                uitgelaat is.
            •   If a charge of an ion is omitted e.g. Cu → Cu2 + 2e-/Indien lading op ioon
                uitgelaat is bv. Cu → Cu2 + 2e-       Max./Maks: 1                                      (2)
                                                                  2

9.5
9.5.1       Copper(II) (ions)/Cu2+ and silver (ions)/Ag+ 
            Koper(II)-(ione) /Cu2+ en silwer-(ione) /Ag+
            Accept/Aanvaar
            Cu (ions) and Ag (ions) (Ions are stated in the question.)
            Cu(-ione) en Ag(-ione) (Ione word in vraag genoem.)                                         (2)

9.5.2       Ag+/silver(I) ions is a stronger oxidising agent  than Cu2+/Copper(II) ions
            and will be reduced (more readily)  to form silver/Ag on the iron rod.
            Ag+/silwer(I) ione is ‘n sterker oksideermiddel as Cu2+/Copper(II) ione en sal
            (meer geredelik) gereduseer word om silwer/Ag op die ysterstaaf te vorm.                    (2 )
                                                                                                        [11]

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Physical Sciences P2/Fisiese Wetenskappe V2       15                                 DBE/2018
                                SCE/SSE – Marking Guidelines/Nasienriglyne

QUESTION 10/VRAAG 10

10.1
10.1.1    (Catalytic) oxidation (of ammonia)/(Katalitiese) oksidasie (van ammoniak)            (1)

10.1.2    Neutralisation/acid-base reaction 
          Neutralisasie/suur-basisreaksie                                                       (1)

10.2
10.2.1    Nitrogen/N 2 /Stikstof                                                               (1)

10.2.2    NO 2 /nitrogen dioxide/Stikstofdioksied                                              (1)

10.2.3    Nitric acid/HNO 3 /Salpetersuur                                                      (1)

10.3
10.3.1   2NH 3 + H 2 SO 4  → (NH 4 ) 2 SO 4                Bal. 
         Notes/Aantekeninge:
         •   Reactants         Products          Balancing 
             Reaktanse          Produkte           Balansering
         •   Ignore double arrows./Ignoreer dubbelpyle.
         •   Marking rule 6.3.10./Nasienreël 6.3.10.                                            (3)

10.3.2   4NH 3 + 5O 2  → 4NO + 6H 2 O                      Bal. 
         Notes / Aantekeninge:
         •   Reactants         Products          Balancing 
             Reaktanse          Produkte           Balansering
         •   Ignore double arrows./Ignoreer dubbelpyle.
         •   Marking rule 6.3.10./Nasienreël 6.3.10.                                            (3)

10.4              28          
          %N=        × 100
                  80 
                = 35%                                                                          (3)
                                                                                                [14]

                                                                             TOTAL/TOTAAL:      150

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