# Technical Sciences Grade 12 P2 NSC November 2020 QP (Eng)

> Grade 12 Technical Sciences Paper 2 question paper from the NSC November Exam 2020 (English), 19 pages. Read online or download the free PDF.

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- Updated: 2026-09-27
- Subject: Technical Sciences
- Grade: Grade 12
- Document type: Question paper
- Year: 2020
- Exam period: NSC November Exam
- Paper: 2
- Curriculum: CAPS
- Pages: 19

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Technical Sciences · Grade 12 · NSC November Exam · 2020. Question paper, 19 pages. Read online or download the PDF.

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                            SENIOR CERTIFICATE/
                        NATIONAL SENIOR CERTIFICATE

                                     GRADE 12

                             TECHNICAL SCIENCES P2

                                  NOVEMBER 2020

MARKS: 150

TIME: 3 hours

             This question paper consists of 15 pages and 4 data sheets.

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INSTRUCTIONS AND INFORMATION

1.        Write your centre number and examination number in the appropriate spaces
          on the ANSWER BOOK.

2.        This question paper consists of NINE 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 subquestions, e.g. between QUESTION 2.1 and
          QUESTION 2.2.

6.        You may use a non-programmable calculator.

7.        You are advised to use the attached DATA SHEETS.

8.        Round off your FINAL numerical answers to a minimum of TWO decimal
          places.

9.        Give brief motivations, discussions etc. where required.

10.       Write neatly and legibly.

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QUESTION 1: MULTIPLE-CHOICE QUESTIONS

Various options are provided as possible answers to the following questions. Choose
the answer and write only the letter (A–D) next to the question numbers (1.1 to 1.10) in
the ANSWER BOOK, e.g. 1.11 D.

1.1        Which ONE of the structural formulae below represents a secondary alcohol?

  A                                                      B                 H
               H     H        H       H                            H   H   O      H
       H       C     C        C       C       O   H            H   C   C   C      C      H
               H     H        H       H                            H   H   H      H

  C                                                      D
                         H
                                                                   H   H   O       H
               H         C    H
               H              H           H                    H   C   C   C       C      H
         H      C        C        C       C       H                H   H           H
                H        O        H       H
                         H                                                                             (2)

1.2        To which homologous series does dichloromethane belong?

           A       Alkanes

           B       Alcohols

           C       Haloalkanes

           D       Carboxylic acids                                                                    (2)

1.3        In which ONE of the options below are the intermolecular forces arranged
           from the weakest to the strongest?

           A       Hydrogen bonds, dipole-dipole forces, London forces

           B       Hydrogen bonds, London forces, dipole-dipole forces

           C       Dipole-dipole forces, London forces, hydrogen bonds

           D       London forces, dipole-dipole forces, hydrogen bonds                                 (2)

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1.4       Alkenes react with hydrogen to form …

          A      alkanes.

          B      alcohols.

          C      aldehydes.

          D      alkynes.                                                                       (2)

1.5       In an electrolytic cell the cations will migrate to the …

          A      cathode and undergo reduction.

          B      anode and undergo oxidation.

          C      cathode and undergo oxidation.

          D      anode and undergo reduction.                                                   (2)

1.6       In the cell notation of a galvanic cell, the double vertical lines (//)
          represent a/the …

          A      phase separator.

          B      solid electrode.

          C      gas electrode.

          D      salt bridge.                                                                   (2)

1.7       Consider the statements below when an incident light ray is reflected from
          a flat surface.

          (i) The angle of incidence is equal to the angle of reflection.
          (ii) The angle measured between the surface and the incident ray is the
                incidence angle.
          (iii) The incidence angle is the angle formed between the incident ray and the
                normal.

          Which statement(s) is/are TRUE?

          A      (i) and (ii)

          B      (i) and (iii)

          C      (ii) only

          D      (i) only                                                                       (2)

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1.8       The diagram below shows light ray LM incident on a rectangular glass prism.

          Which ONE of the following represents the CORRECT emergent ray?

          A      OS

          B      NR

          C      NQ

          D      NP                                                                             (2)

1.9       During the dispersion of white light, which colour in the visible spectrum has
          the smallest angle of refraction?

          A      Green

          B      Violet

          C      Red

          D      Orange                                                                         (2)

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1.10      A learner used a lens (X) to focus the image of a well-illuminated faraway
          building on a screen (S), as shown in the diagram below.

          This lens is …

          A      concave of focal length 4 cm.

          B      convex of focal length 4 cm.

          C      concave of focal length 8 cm.

          D      convex of focal length 8 cm.                                                (2)
                                                                                             [20]

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QUESTION 2 (Start on a new page.)

Organic molecules can be classified into different homologous series that are identified
by their functional groups.

2.1       Define the term functional group.                                                        (2)

2.2       Consider the organic molecules in the table below and answer the questions
          that follow.

                                                         H   H   H   H      H     O
          A                 But-2-ene            B   H   C   C   C   C      C     C
                                                                                      H
                                                         H   H   H   H      H

                        H     H    O
          C       H     C     C    C    O        D           Pentan-2-one

                        H     H             H

          Write down the NAME of the homologous series of compounds represented
          by:

          2.2.1         A                                                                          (1)

          2.2.2         B                                                                          (1)

          2.2.3         C                                                                          (1)

2.3       Write down the IUPAC name of the organic compounds represented by:

          2.3.1         B                                                                          (2)

          2.3.2         C                                                                          (2)

2.4       Draw the structural formulae of the organic compounds represented by:

          2.4.1         A                                                                          (2)

          2.4.2         D                                                                          (2)

2.5       Draw the structural formulae of the ISOMER of the organic compounds
          represented by:

          2.5.1         A                                                                          (2)

          2.5.2         C                                                                          (2)

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2.6       Identify the TYPE of isomer in:

          2.6.1         QUESTION 2.5.1                                                      (1)

          2.6.2         QUESTION 2.5.2                                                      (1)

2.7       Consider compound A.

          2.7.1         Is compound A saturated or unsaturated?                             (1)

          2.7.2         Explain the answer to QUESTION 2.7.1.                               (1)
                                                                                            [21]

QUESTION 3 (Start on a new page.)

The table below shows organic molecules with different molar masses and vapour
pressures.

                                       MOLAR MASS           VAPOUR PRESSURE
           COMPOUND
                                         (g•mol-1)              (x 102 Pa)
            1-propanol                       60                   21,0
            1-butanol                        74                   6,2
            1-pentanol                       88                   2,2

3.1       Define the term vapour pressure.                                                  (2)

3.2       Use the table above to answer questions that follow.

          3.2.1         Describe the trend in the vapour pressure of the compounds
                        above.                                                              (1)

          3.2.2         Explain the answer to QUESTION 3.2.1.

                        Refer to CHAIN LENGTH/MOLAR MASS, STRENGTH OF
                        INTERMOLECULAR FORCES and ENERGY.                                   (3)

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3.3       Consider the graph below that indicates the boiling points of alkanes and
          aldehydes.

          3.3.1         Identify the homologous series represented by graphs A and B
                        respectively.                                                              (2)

          3.3.2         Explain the difference in the boiling points of the two homologous
                        series represented by graphs A and B. Refer to the TYPE and
                        STRENGTH of the intermolecular forces.                                     (3)
                                                                                                   [11]

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QUESTION 4 (Start on a new page.)

Use the flow diagram below to answer the questions that follow.

                     H             H                              H   H
                                              A
                         C     C                          H       C   C     OH
                     H             H                              H   H

                              B                                   C

                                         Bromoethane

4.1       Write down the NAME or TYPE of reaction represented by the following
          letters:

          4.1.1         A                                                                         (1)

          4.1.2         B                                                                         (1)

          4.1.3         C                                                                         (1)

4.2       Apart from the alkene, another reactant and a catalyst are needed in
          reaction A. Write down the NAME or FORMULA of the:

          4.2.1         Other reactant                                                            (1)

          4.2.2         Catalyst                                                                  (1)

4.3       Use STRUCTURAL FORMULAE to write down a balanced chemical equation
          for reaction B.                                                                         (3)

4.4       Write TWO reaction conditions for reaction C.                                           (2)

4.5       Use molecular formulae to write down a balanced equation for the reaction of
          the alkene in the flow diagram in excess oxygen.                                        (3)

4.6       Write down the NAME of the organic compound in the flow diagram that can
          be used as a monomer of polythene.                                                      (1)
                                                                                                  [14]

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QUESTION 5 (Start on a new page.)

The diagram below represents the electrolysis of copper(ll) chloride.

                                       Copper(II) chloride

5.1       Define the term electrolysis.                                                         (2)

5.2       Is the electrolysis of copper(II) chloride a spontaneous or a non-spontaneous
          reaction?                                                                             (1)

5.3       Explain the answer to QUESTION 5.2.                                                   (1)

5.4       Write down the FORMULA of an electrolyte used in the cell above.                      (1)

5.5       At which electrode will the following observations be made? Write down only
          ANODE or CATHODE.

          5.5.1         Gas bubbles are formed.                                                 (1)

          5.5.2         A brownish deposit is formed.                                           (1)

5.6       Define the term reducing agent.                                                       (2)

5.7       For the cell above, write down the:

          5.7.1         Oxidation half-reaction                                                 (2)

          5.7.2         Reduction half-reaction                                                 (2)

          5.7.3         Net reaction                                                            (2)
                                                                                                [15]

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QUESTION 6 (Start on a new page.)

6.1       The cell notation Zn(s)|Zn2+ (aq)║Cu2+ (aq)|Cu(s) represents a galvanic cell
          operating under standard conditions.

          6.1.1         Define the term galvanic cell.                                                (2)

          6.1.2         Draw a labelled diagram to represent the Zn-Cu cell. Show the
                        direction of electron flow in the external circuit.                           (5)

          6.1.3         Write down TWO standard conditions under which the Zn-Cu cell
                        operates.                                                                     (2)

          6.1.4         To which half-cell do the anions in the salt bridge migrate?                  (1)

          6.1.5         Explain the answer to QUESTION 6.1.4.                                         (2)

6.2       The anode in the Zn-Cu cell is replaced by an unknown electrode, X. The
          voltmeter gives a reading of 2,00 V.

          6.2.1         Identify electrode X by means of a calculation.                               (5)

          6.2.2         Write down the half-reaction taking place at the anode.                       (2)

          6.2.3         Which electrode will experience a decrease in mass?                           (1)

          6.2.4         Explain the answer to QUESTION 6.2.3.                                         (2)
                                                                                                      [22]

QUESTION 7 (Start on a new page.)

7.1       The diagram below shows the reflection of a light ray that strikes a flat mirror
          with a 30° angle of incidence.

                                                Line M

          7.1.1         What is reflection?                                                           (2)

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          Use the diagram to write down the NAMES of:

          7.1.2         Ray AO                                                                       (1)

          7.1.3         Ray OB                                                                       (1)

          7.1.4         Line M                                                                       (1)

          7.1.5         Angle 1                                                                      (1)

          7.1.6         Angle 2                                                                      (1)

7.2       What is the magnitude of angle 2?                                                          (1)

7.3       How will the speed of light be affected when a light ray travels from air into
          water, perpendicular to the surface?                                                       (1)

7.4       A light ray enters the water from air at an angle.

          7.4.1         Which medium, air or water, has the higher optical density?                  (1)

          7.4.2         What will happen to the DIRECTION of the light ray as it enters the
                        water?                                                                       (1)

          7.4.3         Write down the NAME of the phenomenon in QUESTION 7.4.2.                     (1)

7.5       A ray of light moves from water towards air and strikes the interfase
          (boundary) at an angle of incidence smaller than the critical angle.

          7.5.1         Define the term critical angle.                                              (2)

          7.5.2         What observation will be made?                                               (2)

          The incident angle in QUESTION 7.5 is changed such that the ray undergoes
          total internal reflection.

          7.5.3         Describe the phenomenon total internal reflection.                           (2)

          7.5.4         Is the incident angle GREATER THAN or SMALLER THAN the
                        critical angle?                                                              (1)
                                                                                                     [19]

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QUESTION 8 (Start on a new page.)

8.1       Define the term dispersion.                                                             (2)

8.2       Name any FOUR colours in visible light.                                                 (4)

8.3       State THREE properties of the image formed in a plane mirror.                           (3)

8.4       Redraw the diagrams below in the ANSWER BOOK and complete EACH to
          show the path of the ray after passing through the lens.

          8.4.1

                                                                                                  (1)

          8.4.2

                                                                                                  (2)

          8.4.3

                                                                                                  (2)
                                                                                                  [14]

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QUESTION 9 Start on a new page.)

9.1       Define an electromagnetic wave.                                                     (2)

9.2       Which property of radio waves makes it suitable to transmit a signal over
          long distances?                                                                     (1)

9.3       What is a photon?                                                                   (1)

9.4       Write down the NAME of the electromagnetic wave that is used:

          9.4.1         To detect counterfeit notes                                           (1)

          9.4.2         To open and close automatic doors                                     (1)

          9.4.3         In navigation systems                                                 (1)

9.5       What is the relationship between the frequency of light and its wavelength?         (2)

9.6       Calculate the energy of light with a wavelength of 4,06 x 10-11 m.                  (5)
                                                                                              [14]

                                                                                TOTAL:        150

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                             DATA FOR TECHNICAL SCIENCES GRADE 12
                                           PAPER 2

                    GEGEWENS VIR TEGNIESE WETENSKAPPE GRAAD 12
                                    VRAESTEL 2

TABLE 1: PHYSICAL CONSTANTS

               NAME                            SYMBOL                    VALUE
 Standard pressure                               p            1,01 x 105 Pa
 Standard temperature                            T            0 oC/273 K
 Speed of light in a vacuum                      c             3,0 x 108 m·s-1
 Planck's constant                               h             6,63 x 10-34 J·s

TABLE 2: WAVES, SOUND AND LIGHT

                                                          1
 vf                                                T
                                                          f
                         c
 E  hf     or E  h
                         

TABLE 3: FORMULAE

 Eθcell  Eθcathode  Eθanode

 Eθcell  Ereduction
           θ
                      Eθoxidation

 Eθcell  Eθoxidisingagent  Ereducing
                              θ
                                       agent

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                                                                TABLE 4: THE PERIODIC TABLE OF ELEMENTS
                                                               TABEL 4: DIE PERIODIEKE TABEL VAN ELEMENTE

       1           2           3           4           5           6           7           8            9           10          11           12           13        14             15       16          17         18
      (I)         (II)                                                                                                                                   (III)     (IV)            (V)     (VI)        (VII)      (VIII)
                                                                                    Atomic number
        1                                        KEY/SLEUTEL                          Atoomgetal                                                                                                                     2
2,1    H                                                                                                                                                                                                           He
        1                                                                                  29                                                                                                                       4
        3           4                             Electronegativity                                         Symbol                                          5           6           7           8           9       10
1,0         1,5                                                                      1,9   Cu                                                      2,0           2,5         3,0         3,5         4,0
       Li          Be                            Elektronegatiwiteit
                                                                                           63,5
                                                                                                            Simbool                                        B            C           N          O            F      Ne
        7           9                                                                                                                                      11          12           14         16          19       20
       11           12                                                                                                                                     13          14           15         16          17       18
0,9   Na    1,2   Mg                                           Approximate relative atomic mass                                                    1,5    Aℓ     1,8   Si    2,1    P    2,5    S    3,0   Cℓ       Ar
       23           24                                         Benaderde relatiewe atoommassa                                                              27          28           31         32          35,5     40
       19           20         21          22          23          24          25          26           27          28          29           30            31          32           33         34           35      36
0,8    K    1,0    Ca    1,3   Sc    1,5   Ti    1,6    V    1,6   Cr    1,5   Mn    1,8   Fe     1,8   Co    1,8   Ni    1,9   Cu     1,6   Zn    1,6    Ga     1,8   Ge    2,0   As    2,4   Se    2,8   Br       Kr
       39           40         45          48          51          52          55          56           59          59          63,5         65            70          73           75         79          80       84
       37           38         39          40          41          42          43          44           45          46           47          48            49          50           51         52          53       54
0,8   Rb    1,0    Sr    1,2   Y     1,4   Zr          Nb    1,8   Mo    1,9   Tc    2,2   Ru     2,2   Rh    2,2   Pd    1,9   Ag     1,7   Cd    1,7     In    1,8   Sn    1,9   Sb    2,1   Te    2,5    I       Xe
       86           88         89          91          92          96                      101          103         106         108          112          115          119         122         128         127      131
       55           56         57          72          73          74          75           76           77          78          79           80          81            82          83         84           85       86
0,7   Cs    0,9    Ba          La    1,6   Hf          Ta          W           Re          Os            Ir         Pt          Au           Hg    1,8    Tℓ     1,8   Pb    1,9    Bi   2,0   Po    2,5   At      Rn
      133          137         139         179         181         184         186         190          192         195         197          201          204          207         209
       87           88          89
0,7    Fr   0,9    Ra          Ac                      58          59          60          61           62          63          64           65          66            67          68          69          70      71
                   226
                                                   Ce              Pr      Nd         Pm           Sm           Eu          Gd           Tb          Dy            Ho              Er      Tm          Yb         Lu
                                                   140         141         144                      150         152         157          159         163           165         167         169         173        175
                                                       90          91          92          93           94          95          96           97          98            99      100         101         102        103
                                                   Th          Pa              U       Np           Pu         Am          Cm            Bk              Cf        Es          Fm          Md          No          Lr
                                                   232                     238

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                                             TABLE 5A: STANDARD REDUCTION POTENTIALS

                                                                           Half-reactions                 Eθ (V)
                                                F2(g) + 2e                        ⇌   2F                + 2,87
                                                Co + e
                                                                                         2+
                                                   3+
                                                                                   ⇌   Co                 + 1,81
                                                H2O2 + 2H +2e                     ⇌
                                                           +
                                                                                       2H2O               +1,77
                                                       
                                                MnO 4 + 8H + 5e                                          + 1,51
                                                                                            2+
                                                                       +
                                                                                   ⇌   Mn        + 4H2O
                                                                                            
                                                Cℓ2(g) + 2e                        ⇌   2Cℓ                + 1,36
                                                     2
                                                Cr2O 7 + 14H + 6e                                        + 1,33
                                                                                           3+
                                                            +
                                                                                   ⇌   2Cr + 7H2O
                                                                             
                                                O2(g) + 4H + 4e
                                                                   +
                                                                                   ⇌   2H2O               + 1,23
                                                MnO2+ 4H + 2e
                                                                                          2+
                                                           +
                                                                                   ⇌   Mn + 2H2O          + 1,23
                                                Pt + 2e                           ⇌
                                                  2+
                                                                                       Pt                 + 1,20
                                                Br2(ℓ) + 2e                       ⇌   2Br               + 1,07
                                                     
                                                NO 3 + 4H + 3e                                           + 0,96
                                                           +
                                                                                   ⇌   NO(g) + 2H2O
                                                               
                                                  2+
                                                Hg + 2e                            ⇌   Hg(ℓ)              + 0,85
                                                Ag + e                            ⇌
                                                  +
                                                                                       Ag                 + 0,80
                                                    
                                                NO 3 + 2H + e                                            + 0,80
                                                         +
                                                                                   ⇌   NO2(g) + H2O
                                                                                           2+
                                                  3+
                                                Fe + e                             ⇌   Fe                 + 0,77
                                                O2(g) + 2H + 2e                   ⇌
                                                            +
                                                                                       H2O2               + 0,68
                                                        
                                                I2 + 2e                            ⇌   2I                + 0,54
                                                Cu + e                            ⇌
                                                    +
                                                                                       Cu                 + 0,52

                                                                                                                        Increasing reducing ability
                                                SO2 + 4H + 4e                     ⇌
                                                          +
                                                                                       S + 2H2O           + 0,45

              Increasing oxidising ability
                                                2H2O + O2 + 4e                    ⇌   4OH               + 0,40
                                                Cu + 2e                           ⇌
                                                    2+
                                                                                       Cu                 + 0,34
                                                   2
                                                SO 4 + 4H + 2e                    ⇌                      + 0,17
                                                                   +
                                                                                       SO2(g) + 2H2O
                                                                                           +
                                                  2+
                                                Cu + e                             ⇌   Cu                 + 0,16
                                                Sn + 2e
                                                                                          2+
                                                    4+
                                                                                   ⇌   Sn                 + 0,15
                                                S + 2H + 2e                       ⇌
                                                        +
                                                                                       H2S(g)             + 0,14
                                                2H + 2e                           ⇌
                                                    +
                                                                                       H2(g)               0,00
                                                Fe + 3e                           ⇌                       0,06
                                                    3+
                                                                                       Fe
                                                Pb + 2e                           ⇌                       0,13
                                                    2+
                                                                                       Pb
                                                Sn + 2e                           ⇌                       0,14
                                                    2+
                                                                                       Sn
                                                Ni + 2e                           ⇌                       0,27
                                                  2+
                                                                                       Ni
                                                Co + 2e                           ⇌                       0,28
                                                    2+
                                                                                       Co
                                                Cd + 2e                           ⇌                       0,40
                                                    2+
                                                                                       Cd
                                                Cr + e
                                                                                          2+
                                                                                   ⇌                       0,41
                                                   3+
                                                                                       Cr
                                                Fe + 2e                           ⇌                       0,44
                                                    2+
                                                                                       Fe
                                                Cr + 3e                           ⇌                       0,74
                                                   3+
                                                                                       Cr
                                                Zn + 2e                           ⇌                       0,76
                                                    2+
                                                                                       Zn
                                                2H2O + 2e                         ⇌   H2(g) + 2OH        0,83
                                                Cr + 2e                           ⇌                       0,91
                                                   2+
                                                                                       Cr
                                                Mn + 2e                           ⇌                       1,18
                                                     2+
                                                                                       Mn
                                                Aℓ + 3e                           ⇌                       1,66
                                                   3+
                                                                                       Aℓ
                                                Mg + 2e                           ⇌                       2,36
                                                     2+
                                                                                       Mg
                                                Na + e                            ⇌                       2,71
                                                    +
                                                                                       Na
                                                Ca + 2e                           ⇌                       2,87
                                                    2+
                                                                                       Ca
                                                Sr + 2e                           ⇌                       2,89
                                                   2+
                                                                                       Sr
                                                Ba + 2e                           ⇌                       2,90
                                                    2+
                                                                                       Ba
                                                    +    -
                                                Cs + e                             ⇌   Cs                 - 2,92
                                                K + e                             ⇌                       2,93
                                                 +
                                                                                       K
                                                Li + e                            ⇌                       3,05
                                                  +
                                                                                       Li

Copyright reserved

### Page 19

Downloaded from hlayiso.com
Technical Sciences/P2                                                                                                    DBE/November 2020
                                                                                       SC/NSC

                                         TABLE 5B: STANDARD REDUCTION POTENTIALS

                                                                           Half-reactions                       Eθ (V)
                                            Li + e                                     ⇌                        3,05
                                             +
                                                                                            Li
                                            K + e                                      ⇌                        2,93
                                             +
                                                                                            K
                                            Cs + e                                     ⇌                        2,92
                                               +
                                                                                            Cs
                                            Ba + 2e                                    ⇌                        2,90
                                               2+
                                                                                            Ba
                                            Sr + 2e                                    ⇌                        2,89
                                              2+
                                                                                            Sr
                                            Ca + 2e                                    ⇌                        2,87
                                                2+
                                                                                            Ca
                                            Na + e                                     ⇌                        2,71
                                                +
                                                                                            Na
                                            Mg + 2e                                    ⇌                        2,36
                                                2+
                                                                                            Mg
                                            Aℓ + 3e                                    ⇌                        1,66
                                              3+
                                                                                            Aℓ
                                            Mn + 2e                                    ⇌                        1,18
                                                2+
                                                                                            Mn
                                            Cr + 2e                                                             0,91
                                               2+
                                                                                        ⇌   Cr
                                            2H2O + 2e                                  ⇌   H2(g) + 2OH         0,83
                                            Zn + 2e                                    ⇌                        0,76
                                               2+
                                                                                            Zn
                                            Cr + 3e                                    ⇌                        0,74
                                               3+
                                                                                            Cr
                                            Fe + 2e                                    ⇌                        0,44
                                               2+
                                                                                            Fe
                                            Cr + e
                                                                                               2+
                                                                                        ⇌                        0,41
                                               3+
                                                                                            Cr

          Increasing oxidising ability
                                            Cd + 2e                                    ⇌                        0,40
                                                2+
                                                                                            Cd
                                            Co + 2e                                    ⇌                        0,28
                                                2+

                                                                                                                                Increasing reducing ability
                                                                                            Co
                                            Ni + 2e                                    ⇌                        0,27
                                              2+
                                                                                            Ni
                                            Sn + 2e                                    ⇌                        0,14
                                               2+
                                                                                            Sn
                                            Pb + 2e                                    ⇌                        0,13
                                               2+
                                                                                            Pb
                                            Fe + 3e                                    ⇌                        0,06
                                               3+
                                                                                            Fe
                                            2H + 2e
                                                +
                                                                                        ⇌   H2(g)                0,00
                                            S + 2H + 2e                                ⇌
                                                   +
                                                                                            H2S(g)              + 0,14
                                            Sn + 2e
                                                                                               2+
                                               4+
                                                                                        ⇌   Sn                  + 0,15
                                            Cu + e
                                                                                                +
                                                2+
                                                                                        ⇌   Cu                  + 0,16
                                                     2
                                            SO 4 + 4H + 2e                             ⇌
                                                                       +
                                                                                            SO2(g) + 2H2O       + 0,17
                                                               
                                                 2+
                                            Cu + 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
                                                                                              2+
                                               3+
                                            Fe + e                                      ⇌   Fe                  + 0,77
                                                  
                                            NO 3 + 2H + e
                                                         +
                                                                                        ⇌   NO2(g) + H2O        + 0,80
                                                           
                                                 +
                                            Ag + e                                      ⇌   Ag                  + 0,80
                                            Hg + 2e                                    ⇌
                                              2+
                                                                                            Hg(ℓ)               + 0,85
                                               
                                            NO 3 + 4H + 3e
                                                     +
                                                                                        ⇌   NO(g) + 2H2O        + 0,96
                                                                                               
                                            Br2(ℓ) + 2e                                 ⇌   2Br                 + 1,07
                                            Pt + 2 e                                   ⇌
                                              2+
                                                                                            Pt                  + 1,20
                                            MnO2+ 4H + 2e
                                                                                               2+
                                                        +
                                                                                        ⇌   Mn + 2H2O           + 1,23
                                            O2(g) + 4H + 4e                            ⇌
                                                        +
                                                                                            2H2O                + 1,23
                                                      2
                                            Cr2O 7 + 14H + 6e
                                                                                                  3+
                                                                           +
                                                                                        ⇌   2Cr        + 7H2O   + 1,33
                                                                                               
                                            Cℓ2(g) + 2e                                 ⇌   2Cℓ                 + 1,36
                                                                                            2+
                                            MnO 4          + 8H + 5e
                                                                       +
                                                                                        ⇌   Mn + 4H2O           + 1,51
                                                                               
                                            H2O2 + 2H +2 e
                                                                   +
                                                                                        ⇌   2H2O                +1,77
                                            Co + e
                                                                                               2+
                                               3+
                                                                                        ⇌   Co                  + 1,81
                                            F2(g) + 2e                                 ⇌   2F 
                                                                                                                + 2,87

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