# Technical Sciences Grade 12 P2 Gauteng Mock 2020 QP (Eng)

> Grade 12 Technical Sciences Paper 2 question paper from the Gauteng Mock Exam 2020 (English), 23 pages. Read online or download the free PDF.

- Page: https://www.hlayiso.com/library/grade-12-technical-sciences-2020-gauteng-mock-exam-question-paper-paper-2-english/2d5b3586-c771-489b-85eb-ea14fdbd8ec9
- Updated: 2026-09-28
- Subject: Technical Sciences
- Grade: Grade 12
- Language: English
- Document type: Question paper
- Year: 2020
- Exam period: Gauteng Mock Exam
- Paper: 2
- Curriculum: CAPS
- Pages: 23

Breadcrumbs: [Home](https://www.hlayiso.com/) › [Library](https://www.hlayiso.com/library) › [Grade 12](https://www.hlayiso.com/library/grade-12) › [Technical Sciences](https://www.hlayiso.com/library/grade-12/technical-sciences) › [Technical Sciences Grade 12 P2 Gauteng Mock 2020 QP (Eng)](https://www.hlayiso.com/library/grade-12-technical-sciences-2020-gauteng-mock-exam-question-paper-paper-2-english/2d5b3586-c771-489b-85eb-ea14fdbd8ec9)

## About this document

Technical Sciences · Grade 12 · Gauteng Mock Exam · 2020 · English. Question paper, 23 pages. Read online or download the PDF.

Read it free online on the page above; download the PDF from there.

## Document text

Text extracted from the PDF. Layout, diagrams and tables may not survive extraction.

### Page 1

GAUTENG DEPARTMENT OF EDUCATION
                      PREPARATORY EXAMINATION
                                  2020

                           TECHNICAL SCIENCES

                                PAPER 2

                                 11102

TIME:     3 hours

MARKS: 150

20 pages + 3 data sheets

                                                 P.T.O.

### Page 2

TECHNICAL SCIENCES                            2
                                       (Paper 2)                        11102/20

INSTRUCTIONS AND INFORMATION

1.    Write your name in the appropriate space on the ANSWER BOOK.

2.    This question paper consists of TEN questions. Answer ALL the questions in
      the ANSWER BOOK.

3.    Start EACH question on a NEW page in the ANSWER BOOK.

4.    Number the answers correctly according to the numbering system used in this
      question paper.

5.    Leave ONE line between two sub-questions, for example between
      QUESTION 2.1 and QUESTION 2.2.

6.    Write neatly and legibly.

7.    You may use a non-programmable calculator.

8.    You may use appropriate mathematical instruments.

9.    You are advised to use the attached data sheets.

10.   Show ALL formulae and substitutions in ALL calculations.

11.   Round-off your FINAL numerical answers to a minimum of TWO decimal
      places.
12.
      Give brief motivations, discussions, et cetera where required.

                                                                                    P.T.O.

### Page 3

TECHNICAL SCIENCES                                3
                                          (Paper 2)                             11102/20

QUESTION 1: MULTIPLE-CHOICE QUESTIONS

Four options are provided as possible answers to the following questions. Each
question has only ONE correct answer. Write only the letter (A – D) next to the
question number (1.1 to 1.10) in the ANSWER BOOK.

1.1     To which functional group does methyl ethanoate belong?

        A    Esters

        B    Alcohols

        C    Aldehydes

        D    Carboxylic acids                                                              (2)

1.2     Which of the four organic compounds below belongs to carbonyl group?

        A    Pentane

        B    Pentanol

        C    Pentanone

        D    Pentanoic acid                                                                (2)

1.3     Which of the following, lists the intermolecular forces from the lowest to the
        highest boiling point required to overcome them?

        A    Van der Waals, dipole-dipole, single hydrogen, double hydrogen

        B    Double hydrogen, single hydrogen, dipole-dipole, van der Waals

        C    Single hydrogen, double hydrogen, dipole-dipole, van der Waals

        D    Dipole-dipole, van der Waals, single hydrogen, double hydrogen                (2)

                                                                                           P.T.O.

### Page 4

TECHNICAL SCIENCES                       4
                                       (Paper 2)                    11102/20

1.4   In the flow diagram below, the structural formula of P is …

          A

          B

          C

          D

                                                                               (2)

                                                                               P.T.O.

### Page 5

TECHNICAL SCIENCES                          5
                                           (Paper 2)                       11102/20

QUESTIONS 1.5 to 1.7 are based on the diagram below which represents the
purification of copper.

1.5     The correct statement about the cell represented above is:

        A    It is an electrolytic cell and electrode B is the cathode.

        B    It is an electrolytic cell and electrode A is the anode.

        C    It is a galvanic cell and electrode A is the cathode.

        D    It is a galvanic cell and electrode B is the anode.                      (2)

1.6     Which of the following statements is CORRECT for this process?

        A    Cu is oxidised to copper ions at B.

        B    Cu is reduced to copper ions at B.

        C    Cu2+ ions are reduced to copper at B.

        D    Cu2+ ions are oxidised to copper at A.
                                                                                      (2)

1.7     The most suitable electrolyte to be used in this reaction is …

        A     Zinc Sulphate.

        B     Copper Sulphate.

        C     Magnesium Sulphate.

        D     Aluminium Sulphate.                                                     (2)

                                                                                      P.T.O.

### Page 6

TECHNICAL SCIENCES                                6
                                          (Paper 2)                             11102/20

1.8    Which of the following is TRUE when light rays are reflected from a surface?

       I.     The angle of incidence is equal to the angle of reflection for reflections
              from flat surfaces.

       II.    The angle measured between the surface and the ray is the same
              magnitude as the angle of reflection

       III.   The angle of incidence is found by subtracting the angle made with the
              surface from the normal

       A      I and II

       B      I and III

       C      II only

       D      I only                                                                       (2)

1.9    When a ray of white light is shone onto a triangular glass prism, it spreads
       into the seven colours of the spectrum. Which colour of the visible spectrum
       would have the smallest angle of refraction?

       A       Red
       B       Green
       C       Violet
       D       Orange                                                                      (2)

1.10   Which of the following forms of alternative energies is most commonly used in
       South Africa?

       A       Biodiesel

       B       Hydro energy

       C       Nuclear energy

       D       Photovoltaic cell                                                           (2)

                                                                                           [20]

                                                                                           P.T.O.

### Page 7

TECHNICAL SCIENCES                              7
                                         (Paper 2)                           11102/20

QUESTION 2 (Start on a new page.)

The letters A to F in the table below represent six organic compounds. Use these
compounds to answer the questions that follow.

  A                                                 B

  C                                                 D Methanal

  E                                                 F

                                                                                        P.T.O.

### Page 8

TECHNICAL SCIENCES                           8
                                          (Paper 2)                        11102/20

2.1   Define the term functional group.                                               (2)

2.2   Write down the letter(s) representing organic molecules that is/are an …

      2.2.1     alkene                                                                (1)

      2.2.2     aldehyde                                                               (1)

2.3   Write down IUPAC names of organic molecules represented by the following
      letters:

      2.3.1     B                                                                     (2)

      2.3.2     C                                                                     (2)

      2.3.3     E                                                                     (2)

2.4   Write down the:

      2.4.1     Structural formula of compound D.                                     (2)

      2.4.2     General formula of compound A.                                        (2)

2.5   To which homologous series do organic molecules represented by the
      following letters belong?

      2.5.1     B                                                                     (1)

      2.5.2     F                                                                     (1)

2.6   Many of the plastics we use in everyday life and in industry are made from
      long chains of monomers.

      Define a monomer.                                                               (2)
                                                                                      [18]

                                                                                      P.T.O.

### Page 9

TECHNICAL SCIENCES                            9
                                                             (Paper 2)                        11102/20

QUESTION 3 (Start on a new page.)

As a liquid evaporates, the vapours on the surface of the liquid exert a vapour
pressure. Vapour pressure varies with the liquid's temperature. If atmospheric pressure
changes, a liquid's boiling point will also change.

The graph below illustrates the relationship between vapour pressure and temperature
for TWO organic compounds belonging to the alkane group.

       Vapour pressure/mmHg

3.1                       Define the term vapour pressure.                                                (2)

3.2                       Write down the TYPE of intermolecular forces between organic molecules
                          mentioned in the graph above.                                                   (1)

3.3                       Explain the trend in the boiling points of the two organic molecules shown in
                          the graph above.                                                                (3)

3.4                       Explain the relationship between the vapour pressure and the boiling point in
                          the graph above.                                                                (2)

                                                                                                          P.T.O.

### Page 10

TECHNICAL SCIENCES                               10
                                       (Paper 2)                           11102/20

3.5   The picture below illustrates how much easier it is to pour water than to pour
      syrup into a container.

      3.5.1     Which property of the two liquids is responsible for the manner in
                which they flow into the container?                                    (1)

      3.5.2     Explain the difference in the manner in which the water and syrup
                flow into the containers.                                              (3)

                                                                                       [12]

                                                                                       P.T.O.

### Page 11

TECHNICAL SCIENCES                             11
                                           (Paper 2)                          11102/20

QUESTION 4 (Start on a new page.)

4.1    Ethyne is the gas used in oxyacetylene blow torches during the cutting and
       welding of metals.

       Write down the balanced equation for the reaction above in sufficient oxygen.       (3)

4.2    Compound 1 is an alkene and can undergo addition reaction which is widely
       used in the industry. The flow diagram below shows the different addition
       reactions of COMPOUND 1.

                                                            Primary Alcohol

       Compound 3
                        Reaction A                            Reaction B

                                     Compound 1
           Reaction D                                        Reaction C

                                                         1,2-dibromopropane

          Compound 4

       Write down the IUPAC name of organic molecules represented by:

       4.2.1     Compound 3                                                              (2)

       4.2.2     Compound 4                                                              (2)

                                                                                         P.T.O.

### Page 12

TECHNICAL SCIENCES                  12
                                       (Paper 2)               11102/20

4.3   Write down NAMES of addition reaction represented by …

      4.3.1     Reaction A.                                               (1)

      4.3.2     Reaction B.                                               (1)

      4.3.3     Reaction C.                                               (1)

      4.3.4     Reaction D.                                               (1)

4.4   Use structural formulae to represent:

      4.4.1     Reaction B forming the primary alcohol                    (3)

      4.4.2     Reaction C forming 1,2-dibromopropane                     (3)
                                                                          [17]

                                                                          P.T.O.

### Page 13

TECHNICAL SCIENCES                                13
                                          (Paper 2)                             11102/20

QUESTION 5 (Start on a new page.)

The diagram below illustrates how a Hydrogen Fuel Cell produces electrical energy
directly from a chemical reaction just like a galvanic cell. Hydrogen is oxidized to
protons at the anode, and oxygen is reduced and combines to form water.

5.1     What energy conversion takes place in the Hydrogen represented in the
        diagram above?                                                                     (2)

5.2     At which electrode, A or B, does oxidation occur?                                  (1)

5.3     Which substance in the cell in the diagram above is a reducing agent?              (2)

5.4     Write down the following reactions for the cell in the diagram above.

        5.4.1      Reduction half reaction                                                 (2)

        5.4.2      Overall net cell reaction                                               (3)

        5.4.3      Calculate the emf of the cell in the diagram above.                     (4)

5.5     Mention THREE standard conditions of a galvanic cells.                             (3)
                                                                                           [17]

                                                                                           P.T.O.

### Page 14

TECHNICAL SCIENCES                                 14
                                             (Paper 2)                              11102/20

QUESTION 6 (Start on a new page.)

Gold plating is done using an electrolytic cell where a thin layer of gold is deposited
onto the surface of another metal. A group of technical scientists bought a basic kit
comprising of the apparatus below to perform an experiment on electroplating a metal
spoon.

Connecting wires
A gold electrolyte
A gold electrode
A metal spoon
A power supply
A switch

6.1     Define the term electrolytic cell.                                                     (2)

6.2     The success of the experiment depends on the correct connection of the gold
        electrode and the metal spoon.

        6.2.1   Draw a fully-labelled diagram to show the correct connection of an
                electrolytic cell that will result in the gold plating of the metal spoon.
                Show the positive and the negative terminal of the power supply.               (6)

        6.2.2   Is gold plating a spontaneous or a non-spontaneous reaction?                   (1)

        6.2.3   Explain the answer to QUESTION 6.2.2                                           (2)

        6.2.4   Which electrode is the anode? Write only METAL SPOON/GOLD
                ELECTRODE.                                                                     (1)

        6.2.5   Briefly explain how the metal spoon gets electroplated with gold.              (2)

        6.2.6   Write down TWO reasons why gold plating is preferred in jewellery
                production.                                                                    (2)

                                                                                               P.T.O.

### Page 15

TECHNICAL SCIENCES                                 15
                                         (Paper 2)                            11102/20

6.3   Due to challenges with the economy and high petrol and diesel prices, the
      alternative way for people to fuel their cars might be the production of cars that
      use a fuel cell as a power source, such as the one shown below. In fuel cells,
      the only two products used are water and electricity.

      Mention at least TWO advantages of using the fuel cell car shown above.              (2)
                                                                                           [18]

                                                                                           P.T.O.

### Page 16

TECHNICAL SCIENCES                                16
                                            (Paper 2)                             11102/20

QUESTION 7 (Start on a new page.)

Two light rays originating from points P on an object are reflected by a flat mirror into
the eye of an observer in the diagram below. The reflected rays are obtained by using
the law of reflection.

7.1      State the law of reflection.                                                        (2)

7.2      Write down THREE properties of the image observed.                                  (3)

7.3      Is the image formed real or virtual?                                                (1)

7.4      Light can also undergo total internal reflection.

         7.4.1      Write down TWO conditions for total internal reflection.                 (2)

         7.4.2      Write down TWO optical instruments that use total internal
                    reflection.                                                              (2)

         7.4.3      Draw a simple, labelled diagram representing total internal
                    reflection.                                                              (5)
                                                                                             [15]

                                                                                             P.T.O.

### Page 17

TECHNICAL SCIENCES                               17
                                         (Paper 2)                            11102/20

QUESTION 8 (Start on a new page.)

8.1    Look at the diagram below and answer the questions that follow.

       8.1.1      Which phenomenon best explains the difference in the image of
                  the pencil observed in the water.                                      (1)

       8.1.2      Explain why the image of the pencil in the water that is observed in
                  glass A is different from the image observed in glass B.               (4)

8.2    When a ray of light passes through a triangular glass prism, the light ray
       spreads into seven (7) colours.

       8.2.1      Write down the name of the phenomenon where white light
                  spreads into its seven component colours.                              (1)

       8.2.2      Define the phenomenon in QUESTION 8.2.1.                               (2)

       8.2.3      Write down the seven component colours in order of increasing
                  frequencies.                                                           (7)
                                                                                         [15]

                                                                                         P.T.O.

### Page 18

TECHNICAL SCIENCES                                18
                                             (Paper 2)                             11102/20

QUESTION 9 (Start on a new page.)

After the age of 40 most people find it difficult to see nearby objects. To correct this,
doctors recommend glasses with a lens that can allow them to see objects that are
near.

9.1      Write down the names of TWO types of lenses.                                         (2)

9.2      Write down the NAME of the eye condition when a person cannot see nearby
         objects.                                                                             (1)

9.3      Which type of lens can be used to correct the condition mentioned in
         QUESTION 9.2.                                                                        (1)

9.4      Write down the NAME of the eye condition which is the opposite of the one
         mentioned in QUESTION 9.2.                                                           (1)

9.5      Which type of lens can be used to correct the condition mentioned in
         QUESTION 9.4.                                                                        (1)
                                                                                              [6]

                                                                                              P.T.O.

### Page 19

TECHNICAL SCIENCES                              19
                                      (Paper 2)                          11102/20

QUESTION 10 (Start on a new page.)

10.1   Define the term electromagnetic waves.                                        (2)

10.2   Identify the TYPES of electromagnetic waves associated with the uses in the
       table below.                                                                  (3)

        A     Early detection of cancer and dementia

        B     Detecting counterfeit bank notes

                                                                                     P.T.O.

### Page 20

TECHNICAL SCIENCES                             20
                                        (Paper 2)                           11102/20

        C       Detecting broken bones

10.3   The equation E = hf is used to calculate the energy of a photon

       10.3.1    Define the term photon.                                               (2)

       10.3.2    Calculate the energy of light of which the wavelength is
                 4,06 x 10-11 m.                                                       (5)
                                                                                       [12]

                                                                              TOTAL: 150

                                           END

### Page 21

TECHNICAL SCIENCES                                           21
                                                       (Paper 2)                                         11102/20

                      DATA FOR TECHNICAL SCIENCES GRADE 12
                                     PAPER 2
                   GEGEWENS VIR TEGNIESE WETENSKAPPE GRAAD 12
                                   VRAESTEL 2

TABLE 1 / TABEL 1: PHYSICAL CONSTANTS / FISIESE KONSTANTES

PHYSICAL CONSTANTS / FISIESE KONSTANTES
    CONSTANT / KONSTANTE       SYMBOL / SIMBOOL                                            VALUE / WAARDE
Standard pressure
Standaarddruk                        pƟ                                                        1,01 x 10 Pa
                                                                                                            5

Standard temperature
Standaard temperatuur                                             TƟ                             298 K/25 0C
Speed of light
Spoed van lig                                                      c                           3 x 108 m.s-1
Planck's constant
Planck se konstante                                                h                          6,63 x 10-34 J.s

TABLE 2 / TABEL 2: WAVES, SOUND AND LIGHT / GOLWE, KLANK EN LIG

                                                                  1
𝑣 = 𝑓𝜆                                                      T=
                                                                  𝑓

                       𝑐
E = hf or / of E = h
                       𝜆

TABLE 3 / TABEL 3: ELECTROCHEMISTRY / ELEKTROCHEMIE

Emf / Emk                  Eθcell = Eθcathode − Eθanode / Eθsel = Ekatode
                                                                   θ
                                                                          − Eθanode

                           or / of

                           Eθcell = Ereduction
                                     θ
                                               − Eθoxidation / Eθsel = Ereduksie
                                                                        θ
                                                                                 − Eθoksidasie

                           or / of

                           Eθcell = Eθoxidisingagent − Ereducing
                                                        θ
                                                                 agent / Esel = Eoksideermiddel − Ereduseermiddel
                                                                          θ      θ                 θ

### Page 22

TECHNICAL SCIENCES                                                                                     22
                                                                                     (Paper 2)                            11102/20

                                                               TABLE 4A: STANDARD REDUCTION POTENTIALS
                                                               TABEL 4A: STANDAARD-REDUKSIEPOTENSIALE

                                                                      Half-reactions/Halfreaksies                Eθ (V)
                                                                                         −   ⇌     −             + 2,87
                                                                         F2(g) + 2e              2F
                                                                           Co3+ + e−         ⇌   Co2+            + 1,81
                                                                    H2O2 + 2H+ +2e−          ⇌   2H2O            +1,77
                                                                       −
                                                                  MnO 4 + 8H+ + 5e−          ⇌   Mn2+ + 4H2O     + 1,51
                                                                                     −                 −
                                                                           Cℓ2(g) + 2e       ⇌   2Cℓ             + 1,36
                                                                     2−
                                                                Cr2O 7 + 14H+ + 6e−          ⇌   2Cr3+ + 7H2O    + 1,33
                                                                   O2(g) + 4H+ + 4e−         ⇌   2H2O            + 1,23
                                                                   MnO2 + 4H+ + 2e−          ⇌   Mn2+ + 2H2O     + 1,23
                                                                            2+     −         ⇌   Pt              + 1,20
                                                                           Pt + 2e
                                                                         Br2(ℓ) + 2e−        ⇌   2Br−            + 1,07
                                                                   NO 3− + 4H+ + 3e−         ⇌   NO(g) + 2H2O    + 0,96
                                                                         Hg2+ + 2e−          ⇌   Hg(ℓ)           + 0,85

Increasing oxidising ability / Toenemende oksiderende vermoë
                                                                           Ag+ + e−          ⇌

                                                                                                                              Increasing reducing ability / Toenemende reduserende vermoë
                                                                                                 Ag              + 0,80
                                                                       −
                                                                    NO 3 + 2H+ + e−          ⇌   NO2(g) + H2O    + 0,80
                                                                            Fe3+ + e−        ⇌   Fe2+            + 0,77
                                                                   O2(g) + 2H+ + 2e−         ⇌   H2O2            + 0,68
                                                                             I2 + 2e−        ⇌   2I−             + 0,54
                                                                            Cu+ + e−         ⇌   Cu              + 0,52
                                                                    SO2 + 4H+ + 4e−          ⇌   S + 2H2O        + 0,45
                                                                    2H2O + O2 + 4e−          ⇌   4OH−            + 0,40
                                                                          Cu2+ + 2e−         ⇌   Cu              + 0,34
                                                                     2−
                                                                  SO 4 + 4H+ + 2e−           ⇌   SO2(g) + 2H2O   + 0,17
                                                                             Cu2+ + e−       ⇌   Cu+             + 0,16
                                                                         Sn4+ + 2e−          ⇌   Sn2+            + 0,15
                                                                      S + 2H+ + 2e−          ⇌   H2S(g)          + 0,14
                                                                          2H+ + 2e−          ⇌   H2(g)            0,00
                                                                         Fe3+ + 3e−          ⇌   Fe              − 0,06
                                                                         Pb2+ + 2e−          ⇌   Pb              − 0,13
                                                                         Sn2+ + 2e−          ⇌   Sn              − 0,14
                                                                          Ni2+ + 2e−         ⇌   Ni              − 0,27
                                                                         Co2+ + 2e−          ⇌   Co              − 0,28
                                                                         Cd2+ + 2e−          ⇌   Cd              − 0,40
                                                                           Cr3+ + e−         ⇌   Cr2+            − 0,41
                                                                         Fe2+ + 2e−          ⇌   Fe              − 0,44
                                                                         Cr3+ + 3e−          ⇌   Cr              − 0,74
                                                                         Zn2+ + 2e−          ⇌   Zn              − 0,76
                                                                        2H2O + 2e−           ⇌   H2(g) + 2OH−    − 0,83
                                                                         Cr2+ + 2e−          ⇌   Cr              − 0,91
                                                                         Mn2+ + 2e−          ⇌   Mn              − 1,18
                                                                          Aℓ3+ + 3e−         ⇌   Aℓ              − 1,66
                                                                         Mg2+ + 2e−          ⇌   Mg              − 2,36
                                                                           Na+ + e−          ⇌   Na              − 2,71
                                                                         Ca2+ + 2e−          ⇌   Ca              − 2,87
                                                                          Sr2+ + 2e−         ⇌   Sr              − 2,89
                                                                         Ba2+ + 2e−          ⇌   Ba              − 2,90
                                                                            Cs+ + e-         ⇌   Cs              - 2,92
                                                                             K+ + e−         ⇌   K               − 2,93
                                                                            Li+ + e−         ⇌   Li              − 3,05

### Page 23

TECHNICAL SCIENCES                                                                                23
                                                                                    (Paper 2)                            11102/20

                                                             TABLE 4B: STANDARD REDUCTION POTENTIALS
                                                             TABEL 4B: STANDAARD-REDUKSIEPOTENSIALE

                                                                                                                Eθ (V)
                                                                     Half-reactions/Halfreaksies

                                                                              Li+ + e−      ⇌   Li              − 3,05
                                                                               K+ + e−      ⇌   K               − 2,93
                                                                             Cs+ + e−       ⇌   Cs              − 2,92
                                                                           Ba2+ + 2e−       ⇌   Ba              − 2,90

                                                                                                                          Increasing reducing ability/Toenemende reduserende vermoë
                                                                            Sr2+ + 2e−                          − 2,89

Increasing oxidising ability/Toenemende oksiderende vermoë
                                                                                            ⇌   Sr
                                                                           Ca2+ + 2e−       ⇌   Ca              − 2,87
                                                                             Na+ + e−       ⇌   Na              − 2,71
                                                                           Mg2+ + 2e−       ⇌   Mg              − 2,36
                                                                            Aℓ3+ + 3e−      ⇌   Aℓ              − 1,66
                                                                           Mn2+ + 2e−       ⇌   Mn              − 1,18
                                                                           Cr2+ + 2e−       ⇌   Cr              − 0,91
                                                                          2H2O + 2e−        ⇌   H2(g) + 2OH−    − 0,83
                                                                           Zn2+ + 2e−       ⇌   Zn              − 0,76
                                                                           Cr3+ + 3e−       ⇌   Cr              − 0,74
                                                                           Fe2+ + 2e−       ⇌   Fe              − 0,44
                                                                             Cr3+ + e−      ⇌   Cr2+            − 0,41
                                                                           Cd2+ + 2e−       ⇌   Cd              − 0,40
                                                                           Co2+ + 2e−       ⇌   Co              − 0,28
                                                                            Ni2+ + 2e−      ⇌   Ni              − 0,27
                                                                           Sn2+ + 2e−       ⇌   Sn              − 0,14
                                                                           Pb2+ + 2e−       ⇌   Pb              − 0,13
                                                                           Fe3+ + 3e−       ⇌   Fe              − 0,06
                                                                            2H+ + 2e−       ⇌   H2(g)            0,00
                                                                        S + 2H+ + 2e−       ⇌   H2S(g)          + 0,14
                                                                           Sn4+ + 2e−       ⇌   Sn2+            + 0,15
                                                                            Cu2+ + e−       ⇌   Cu+             + 0,16
                                                                     2−
                                                                 SO 4 + 4H+ + 2e−           ⇌   SO2(g) + 2H2O   + 0,17
                                                                           Cu2+ + 2e−       ⇌   Cu              + 0,34
                                                                   2H2O + O2 + 4e−          ⇌   4OH−            + 0,40
                                                                   SO2 + 4H+ + 4e−          ⇌   S + 2H2O        + 0,45
                                                                           Cu+ + e−         ⇌   Cu              + 0,52
                                                                            I2 + 2e−        ⇌   2I−             + 0,54
                                                                  O2(g) + 2H+ + 2e−         ⇌   H2O2            + 0,68
                                                                           Fe3+ + e−        ⇌   Fe2+            + 0,77
                                                                   NO 3− + 2H+ + e−         ⇌   NO2(g) + H2O    + 0,80
                                                                          Ag+ + e−          ⇌   Ag              + 0,80
                                                                        Hg2+ + 2e−          ⇌   Hg(ℓ)           + 0,85
                                                                     −
                                                                  NO 3 + 4H+ + 3e−          ⇌   NO(g) + 2H2O    + 0,96
                                                                                        −          −
                                                                        Br2(ℓ) + 2e         ⇌   2Br             + 1,07
                                                                         Pt2+ + 2 e−        ⇌   Pt              + 1,20
                                                                  MnO2 + 4H+ + 2e−          ⇌   Mn2+ + 2H2O     + 1,23
                                                                  O2(g) + 4H+ + 4e−         ⇌   2H2O            + 1,23
                                                                   2−
                                                               Cr2O 7 + 14H+ + 6e−          ⇌   2Cr3+ + 7H2O    + 1,33
                                                                                     −                −
                                                                          Cℓ2(g) + 2e       ⇌   2Cℓ             + 1,36
                                                                     −
                                                                 MnO 4 + 8H+ + 5e−          ⇌   Mn2+ + 4H2O     + 1,51
                                                                  H2O2    + 2H+ +2 e−       ⇌   2H2O            +1,77
                                                                            Co3+ + e−       ⇌   Co2+            + 1,81
                                                                           F2(g) + 2e−      ⇌   2F−             + 2,87

## Related documents

- [TECH SC P1 (English) 2020 Preparatory Question Paper](https://www.hlayiso.com/library/grade-12-technical-sciences-2020-gauteng-mock-exam-question-paper-paper-1-english/1341488b-8f86-4452-ad0e-752466837276) — Technical Sciences · QP · 2020 · Eng
- [TECH SCIENCES P2 GR12 QP SEPT2020 English](https://www.hlayiso.com/library/tech-sciences-p2-gr12-qp-sept2020-english/7794b3fd-657f-4ff3-bd5a-def6820d1255) — Technical Sciences · QP · 2020 · Eng
- [Gr12 Technical Sciences P2 (English) 2021 Preparatory Question Paper](https://www.hlayiso.com/library/gr12-technical-sciences-p2-english-2021-preparatory-question-paper/c5183447-27b2-42e8-89b6-1fe6b8275dc0) — Technical Sciences · QP · 2021 · Eng
- [Tech SC P2 (English) X10 2019 Preparatory Examination Question Paper](https://www.hlayiso.com/library/tech-sc-p2-english-x10-2019-preparatory-examination-question-paper/7cbf335b-4acc-4cfa-9017-65aa032b487c) — Technical Sciences · QP · 2019 · Eng
- [Tech SC P2 (English) X05 2019 Preparatory Examination Question Paper](https://www.hlayiso.com/library/tech-sc-p2-english-x05-2019-preparatory-examination-question-paper/a8a7749b-eacd-497c-a0ab-b68374e5f186) — Technical Sciences · QP · 2019 · Eng
- [TECH SCIENCES P1 GR12 QP SEPT2020 English (Signing off 27 July)](https://www.hlayiso.com/library/tech-sciences-p1-gr12-qp-sept2020-english-signing-off-27-july/0f7d69d0-c47d-41a1-a835-f9e13408d8ed) — Technical Sciences · QP · 2020 · Eng

## More from Grade 12 Technical Sciences

- [Grade 12 Technical Sciences P1 November 2026 Mock Memo](https://www.hlayiso.com/library/grade-12-technical-sciences-2026-nsc-november-mock-exam-memorandum-paper-1/5543b9af-5bb3-4e43-95e3-ad6028ca21e8) — Memo · 2026 · Eng
- [Gr 12 Tech Sci ATP 2023-24](https://www.hlayiso.com/library/gr-12-tech-sci-atp-2023-24/a7a03e64-2e18-4f50-a7fa-6eb1a25136c7) — ATP
- [TECH SC P1 MEMO GR12 SEPT 2025 E+A watermark](https://www.hlayiso.com/library/tech-sc-p1-memo-gr12-sept-2025-e-a-watermark/4a156330-3801-46dc-b908-43c35dc64891) — Memo · 2025
- [TECHNICAL SCIENCES P2 MG GR12 SEPT2025 watermark](https://www.hlayiso.com/library/technical-sciences-p2-mg-gr12-sept2025-watermark/717f8fcd-96bb-4848-8cb7-68903a8f0550) — Memo · 2025
- [Technical Sciences P1 Erratum June Commom Updated](https://www.hlayiso.com/library/technical-sciences-p1-erratum-june-commom-updated/c0a5373a-1bd4-4019-b849-f2a26fa7ab0b) — Errata · 2024
- [TECH SCIENCES P1 GR12 MEMO JUNE 2024 Afr+English](https://www.hlayiso.com/library/tech-sciences-p1-gr12-memo-june-2024-afr-english/7f012694-b60e-4910-b0d6-e43dd5b126e8) — Memo · 2024 · Eng

## Collection

- [Grade 12 past papers](https://www.hlayiso.com/grade-12/past-papers)

---

Hlayiso: free CAPS and IEB past papers, memos, notes and study guides for South African learners. When citing, link the page URL above, not a PDF or /api/ URL.
