Physical Sciences Grade 12 P2 Free StateNovember 2014 QP

Downloaded from hlayiso.com PREPARATORY EXAMINATION GRADE 12 SEPTEMBER 2014 PHYSICAL SCIENCES PAPER 2 (CHEMISTRY) MARKS: 150 TIME: 3 HOURS This question paper consists of 15 pages and 4 data sheets. Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 2 FS September 2014 PREPARATORY EXAMINATION 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. Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 3 FS September 2014 PREPARATORY EXAMINATION QUESTION 1: MULTIPLE-CHOICE QUESTIONS Four options are provided as possible answers to the following questions. Each question has only ONE correct answer. Choose the answer and write only the letter A, B, C or D next to the question number (1.1 – 1.10) in your ANSWER BOOK. 1.1 The monomer of polyethene is … A ethane. B ethene. C propene. D polythene. (2) 1.2 The main product formed during the Ostwald process is … A ammonia. B ammonium nitrate. C nitric acid. D sulphuric acid. (2) 1.3 The melting points of four straight chain hydrocarbons (A, B, C and D) are shown in the table below. Hydrocarbon Melting point (°C) A -182,5 B -95 C 28 D -56,5 Which ONE of the above hydrocarbons has the strongest intermolecular forces? A A B B C C D D (2) Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 4 FS September 2014 PREPARATORY EXAMINATION 1.4 When copper(II) carbonate reacts with excess acid, carbon dioxide is produced. The graphs below were obtained under two different reaction conditions. Volume of CO2 (cm3) P Q Time (s) The change from P to Q could be brought about by … A increasing the concentration of the acid. B decreasing the mass of the copper(II) carbonate. C decreasing the particle size of the copper(II) carbonate. D adding a catalyst. (2) 1.5 A beaker contains a 0,01 mol·dm-3 NaOH solution. A spoonful of a soluble compound, X, is added to the solution and the pH of the solution decreases. Compound X could be … A ammonium carbonate. B sodium carbonate. C sodium chloride. D ammonium chloride. (2) 1.6 Which ONE of the following half-reactions occurs at the ANODE during the electroplating of an iron spoon with copper? A Fe2+ + 2e- → Fe B Cu2+ + 2e- → Cu C Cu → Cu2+ + 2e- D Fe → Fe2+ + 2e- (2) Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 5 FS September 2014 PREPARATORY EXAMINATION 1.7 Which ONE of the following reactions will occur spontaneously? A Pt2+ + Cu → Pt + Cu2+ B Cu + Zn2+ → Cu2+ + Zn C Sn + Zn → Sn2+ + Zn2+ D Sn + Fe2+ → Sn2+ + Fe (2) 1.8 The diagram below represents an electrochemical cell. V A salt bridge B Copper(II) sulphate Zinc(II) nitrate solution solution Consider the following statements regarding the above cell: I: It is a galvanic cell with B as anode. II: It is an electrolytic with B as anode. III: Copper(II) ions are reduced to copper at A. IV: Zinc(II) ions act as reducing agent. Which of the above statements is/are true regarding the above cell? A I and III B III and IV C II and IV D I, III and IV (2) Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 6 FS September 2014 PREPARATORY EXAMINATION 1.9 The following reaction reaches equilibrium in a closed container at a constant temperature. CaCO3(s) ⇌ CaO(s) + CO2(g) ∆H > 0 The mass of the CaO(s) in the container can be increased by … A adding more CaCO3(s). B lowering the temperature. C removing some of the CO2(g). D reducing the volume of the container. (2) 1.10 The ionisation of water reaches equilibrium at 25 °C: 2H2O(ℓ) ⇌ H3O+(aq) + OH-(aq) ∆H > 0 The temperature is now increased to 40 °C and a new equilibrium is established. Which ONE of the following is correct at this higher temperature? KW pH Nature of solution A Larger Smaller than 7 Acidic B Larger Smaller than 7 Neutral C Smaller Greater than 7 Basic D Smaller Greater than 7 Neutral (2) [20] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 7 FS September 2014 PREPARATORY EXAMINATION QUESTION 2 (Start on a new page.) The letters A to H in the table below represent eight organic compounds. H H H O H C C C C H H H H H A H C C O H B H C H H H C H H H C (CH3)2CHCHC(CH3)CH2CH3 D 1,2-dibromo-3-methylbutane E Propanoic acid F CH3CCCH(C2H5)CH2CH3 G (CH3)2CHCH2CH(CH3)CH2CH3 H 4-methylpentan-2-one 2.1 Write down the letter(s) that represent(s): 2.1.1 A compound with a carboxyl group as functional group (1) 2.1.2 An alkene (1) 2.1.3 An aldehyde (1) 2.1.4 A saturated hydrocarbon (1) 2.1.5 Two compounds that are functional isomers (1) 2.2 Write down the IUPAC name of: 2.2.1 Compound B (2) 2.2.2 Compound F (2) 2.2.3 Compound G (2) 2.3 Write down the structural formula of: 2.3.1 Compound D (2) 2.3.2 Compound H (2) 2.4 Compound A and compound E is heated in the presence of a few drops of concentrated sulphuric acid. Write down the: 2.4.1 Type of reaction that takes place (1) 2.4.2 Structural formula of the organic product (2) [18] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 8 FS September 2014 PREPARATORY EXAMINATION QUESTION 3 (Start on a new page.) Compounds A to E, shown in the table below, are used during two investigations to determine factors which influence boiling point. The compounds are of similar molecular mass and therefore it is considered as a controlled variable. Relative Boiling Investigation Compound molecular mass point (°C) A 2-methylbutane 72 27 I B 2,2-dimethylpropane 72 9 C Pentane 72 36 D CH3CH2CH2CH2OH 74 117 II E CH3CH2CH2CHO 72 75 3.1 Compounds A, B and C are structural isomers. Write down the: 3.1.1 Name of the homologous series to which they belong (1) 3.1.2 Type of structural isomerism shown by these compounds (1) 3.2 Consider the boiling points of the compounds in investigation I. 3.2.1 Write down the independent variable for this investigation. (1) 3.2.2 Fully explain why boiling point increases from compound A to compound C. (3) 3.2.3 Which ONE of compounds B or C will have the higher vapour pressure at a given temperature? Refer to the data in the table to give a reason for the answer. (2) 3.3 Write down the type of intermolecular forces (Van der Waals forces) between molecules of each of the following compounds: 3.3.1 Compound C (1) 3.3.2 Compound D (2) 3.4 Consider investigation II. Refer to the type of Van der Waals forces in each of the compounds to give a reason why the boiling point of compound D is higher than that of compound E. (2) [13] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 9 FS September 2014 PREPARATORY EXAMINATION QUESTION 4 (Start on a new page.) In the flow diagram below prop-1-ene is used as starting reagent in the preparation of other compounds. P to T represent chemical reactions. P Prop-1-ene Alcohol Q R T S Alkane Haloalkane Cℓ2 4.1 Name the type of reaction represented by: 4.1.1 P (1) 4.1.2 S (1) 4.1.3 Q (1) 4.2 Consider reaction P. Write down the: 4.2.1 FORMULA of a suitable catalyst (1) 4.2.2 Structural formula of the alcohol (2) 4.3 For reaction R, write down: 4.3.1 The type of addition reaction (1) 4.3.2 A balanced equation using structural formulae (3) 4.4 During reaction T, the haloalkane reacts with a base to form the alcohol in QUESTION 4.2.2. Write down the: 4.4.1 IUPAC name of the haloalkane (2) 4.4.2 NAME of a suitable base (1) 4.4.3 TWO reaction conditions for this reaction (2) [15] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 10 FS September 2014 PREPARATORY EXAMINATION QUESTION 5 (Start on a new page.) Hydrochloric acid reacts with an excess of magnesium chunks according to the following balanced equation: Mg(s) + 2HCℓ(aq) → MgCℓ2(aq) + H2(g) (∆H < 0 ) 5.1 Give a reason why the rate of the above reaction gradually decreases as the reaction proceeds. (1) 5.2 Redraw the set of axes below in your answer book. Mass (g) Time (s) Sketch the graph showing how the mass of magnesium changes until completion of the reaction. (2) 5.3 How will an increase in temperature influence the rate of the above reaction. Write down INCREASES, DECREASES or NO EFFECT. Refer to the collision theory to fully explain the answer. (3) 5.4 Sketch a graph of potential energy versus course of reaction for this reaction. Use the letters (a) to (d) below to clearly label the graph. (a) Reactants (b) Products (c) Activation energy (d) Heat of reaction (4) 5.5 Initially 100 cm3 of a 2 mol·dm-3 HCℓ solution is added to 12 g of magnesium chunks. Calculate the mass of magnesium in excess. (5) [15] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 11 FS September 2014 PREPARATORY EXAMINATION QUESTION 6 (Start on a new page.) The reaction represented by the equation below reaches equilibrium in a closed container at a certain temperature. CS2(g) + 3Cℓ2(g) ⇌ S2Cℓ2(g) + CCℓ4(g) (∆H < 0) 6.1 Is the above equilibrium a HOMOGENEOUS or a HETEROGENEOUS equilibrium? Give a reason for the answer. (2) 6.2 Initially 1,2 moles of CS2(g) and 4 moles of Cℓ2(g) are injected into a 2 dm3 sealed container. Analysis of the equilibrium mixture shows that 138,6 g of CCℓ4(g) is present. Calculate the equilibrium constant (Kc) at this temperature. (8) 6.3 The pressure is now decreased by increasing the volume at constant temperature. How will this change influence the following? (Only write down INCREASES, DECREASES or REMAINS THE SAME.) 6.3.1 Concentration of CCℓ4(g) (1) 6.3.1 Value of the equilibrium constant (Kc) (1) The graph below shows the changes in rate of the reaction after further changes were made to the above equilibrium mixture. Forward reaction: Reverse reaction: Rate (mol·s-1) 0 5 10 15 22 Time (min) 6.4 Write down the disturbance responsible for the sudden change in reaction rate in the 5th minute. (1) 6.5 Did the temperature INCREASE or DECREASE in the 15th minute? (1) 6.6 Fully explain the change in rate of both the forward and reverse reactions from the 15th until the 22nd minute. (5) [19] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 12 FS September 2014 PREPARATORY EXAMINATION QUESTION 7 (Start on a new page.) 7.1 Sulphuric acid is a strong acid and an example of an acid which can donate two protons per molecule. 7.1.1 Write down one word or term for the underlined phrase. (1) The equations below represent the ionisation of sulphuric acid. Equation I: H2SO4(aq) + H2O(ℓ) ⇌ H3O+(aq) + HSO −4 (aq) Equation II: HSO −4 (aq) + H2O(ℓ) ⇌ H3O+(aq) + SO24 − (aq) 7.1.2 Write down the FORMULA of a species that acts as ampholyte in the above reactions. (1) 7.1.3 Write down the NAME of the conjugate base of the hydrogen sulphate ion. (1) 7.2 A learner adds an impure sample of sodium carbonate into a flask containing 50 cm3 of a hydrochloric acid solution with a pH = 0. The hydrochloric acid is in excess. The balanced equation for the reaction that takes place is: Na2CO3 + 2HCℓ → 2NaCℓ + CO2 + H2O 7.2.1 Calculate the number of moles of hydrochloric acid present in the flask. (5) 7.2.2 Write down a balanced equation that explains why a sodium carbonate solution has a pH greater than 7. (3) 7.2.3 The apparatus illustrated below is used during a titration to determine the mass of sodium carbonate present in the sample. A Write down the name of the apparatus labelled A. (1) 7.2.4 During the titration, the excess hydrochloric acid is neutralised by 30 cm3 of a 0,4 mol·dm-3 sodium hydroxide solution. Calculate the mass of sodium carbonate in the sample. (6) [18] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 13 FS September 2014 PREPARATORY EXAMINATION QUESTION 8 (Start on a new page.) The electrochemical cell represented below is made up of a standard Pb│Pb2+ half-cell and a standard unknown half-cell. The unknown half-cell consists of a metal electrode, X, dipped into a solution of a salt of the metal. 1,53 V e- V Pb salt bridge Electrode X Unknown half-cell Pb2+(aq) 8.1 Which electrode (Pb or X) is the anode? (1) 8.2 Identify electrode X with the aid of a calculation. (5) 8.3 The Pb│Pb2+ half-cell is now replaced with a standard Ag│Ag+ electrode. 8.3.1 How will the initial cell potential of this cell compare to that of the above cell? Write down HIGHER THAN LOWER THAN or EQUAL TO. Explain the answer by comparing the relative strengths of the oxidising agents. ..(2) 8.3.2 Write down the cell notation for this cell. ..(3) [11] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 14 FS September 2014 PREPARATORY EXAMINATION QUESTION 9 (Start on a new page.) The simplified diagram below represents an electrochemical cell used for the electrolysis of a concentrated sodium chloride solution. power source P Q Concentrated NaCℓ(aq) 9.1 Is the above cell a GALVANIC or an ELECTROLYTIC cell? (1) 9.2 Chlorine gas is released at electrode Q. Write down the: 9.2.1 Electrode (P or Q) at which reduction takes place (1) 9.2.2 Half-reaction that takes place at electrode P (2) 9.2.3 Direction (P TO Q or Q TO P) in which electrons flow in the external circuit (1) 9.2.4 NAME of the species that acts as reducing agent (1) 9.3 Write down the balanced net (overall) cell reaction taking place in this cell. (3) [9] Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 15 FS September 2014 PREPARATORY EXAMINATION QUESTION 10 (Start on a new page.) Thabo wants to start a vegetable garden in his community. The department of agriculture donates the four fertilisers described below. FERTILISER A: 7:1:3 (21) FERTILISER B: 3:2:1 (28) FERTILISER C: 2:3:4 (22) FERTILISER D: Ammonium sulphate 10.1 What is the meaning of (21) indicated at fertiliser A? (1) 10.2 From FERTILISERS A, B and C, choose a fertiliser which is most suitable for: 10.2.1 Spinach (1) 10.2.2 Tomatoes (1) 10.2.3 Maize (1) 10.3 Calculate the: 10.3.1 Percentage of nitrogen in fertiliser B (2) 10.3.2 Mass of potassium present in a 20 kg bag of fertiliser C (3) 10.4 Write down a balanced equation for the preparation of fertiliser D from ammonia and a suitable acid. (3) [12] GRAND TOTAL: 150 Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 FS September 2014 PREPARATORY EXAMINATION DATA FOR PHYSICAL SCIENCES GRADE 12 PAPER 2 (CHEMISTRY) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 12 VRAESTEL 2 (CHEMIE) TABLE 1: PHYSICAL CONSTANTS/TABEL 1:FISIESE KONSTANTES NAME/NAAM SYMBOL/SIMBOOL VALUE/WAARDE Standard pressure pθ 1,013 x 105 Pa Standaarddruk Molar gas volume at STP Vm 22,4 dm3·mol-1 Molêre gasvolume by STD Standard temperature Tθ 273 K Standaardtemperatuur Charge on electron e -1,6 x 10-19 C Lading op 'n elektron Avogadro’s constant NA 6,02 x 1023 mol-1 Avogadro-konstante TABLE 2: FORMULAE/TABEL 2: FORMULES m N n= n= M NA n m V c= OR c = n= V MV Vm c a Va n a = pH = -log[H3O+] c b Vb n b Kw = [H3O+][OH-] = 1 x 10-14 at 298 K Eθcell = Eθcathode − E θanode / E θsel = E katode θ − E θanode E θcell = E reduction θ − E θoxidation / E θsel = E reduksie θ − E θoksidasie E θcell = E θoxidising agent − E reducing θ θ θ θ agent / E sel = E oksideermi ddel − E reduseermi ddel Copyright Reserved Please turn over

Physical Sciences P2 Downloaded from hlayiso.com FS September 2014 PREPARATORY EXAMINATION TABLE 3: THE PERIODIC TABLE OF ELEMENTS TABEL 3: 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) Atomic number (III) (IV) (V) (VI) (VII) (VIII) 1 KEY/SLEUTEL Atoomgetal 2 2,1 H He 1 29 4 3 4 Electronegativity Symbol 5 6 7 8 9 10 1,9 Cu 1,0 Li 1,5 Be Elektronegatiwiteit Simbool 2,0 B 2,5 C 3,0 N 3,5 O 4,0 F Ne 7 9 63,5 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 226 58 59 60 61 62 63 64 65 66 67 68 69 70 71 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 Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 FS September 2014 PREPARATORY EXAMINATION TABLE 4A: STANDARD REDUCTION POTENTIALS TABEL 4A: STANDAARD-REDUKSIEPOTENSIALE Half-reactions / Halfreaksies E θ (V) F2(g) + 2e− ⇌ 2F− + 2,87 3+ − 2+ Co +e ⇌ Co + 1,81 + H2O2 + 2H +2e− ⇌ 2H2O +1,77 − + 2+ MnO 4 + 8H + 5e− ⇌ Mn + 4H2O + 1,51 − − Cℓ2(g) + 2e ⇌ 2Cℓ + 1,36 2− + 3+ Cr2O 7 + 14H + 6e− ⇌ 2Cr + 7H2O + 1,33 + − O2(g) + 4H + 4e ⇌ 2H2O + 1,23 + − 2+ MnO2 + 4H + 2e ⇌ Mn + 2H2O + 1,23 2+ − Pt + 2e ⇌ Pt + 1,20 Br2(ℓ) + 2e− ⇌ 2Br− + 1,07 − + NO 3 + 4H + 3e− ⇌ NO(g) + 2H2O + 0,96 2+ − Hg + 2e Hg(ℓ) + 0,85 Increasing oxidising ability / Toenemende oksiderende vermoë Increasing reducing ability / Toenemende reduserende vermoë ⇌ + Ag + e− ⇌ Ag + 0,80 − + NO 3 + 2H + e− ⇌ NO2(g) + H2O + 0,80 3+ − 2+ Fe +e ⇌ Fe + 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 2+ Cu + 2e− ⇌ Cu + 0,34 2− + SO 4 + 4H + 2e− ⇌ SO2(g) + 2H2O + 0,17 2+ − + Cu +e ⇌ Cu + 0,16 4+ − 2+ Sn + 2e ⇌ Sn + 0,15 + S + 2H + 2e− ⇌ H2S(g) + 0,14 + 2H + 2e− ⇌ H2(g) 0,00 3+ − Fe + 3e ⇌ Fe − 0,06 2+ Pb + 2e− ⇌ Pb − 0,13 2+ − Sn + 2e ⇌ Sn − 0,14 2+ Ni + 2e− ⇌ Ni − 0,27 2+ − Co + 2e ⇌ Co − 0,28 2+ Cd + 2e− ⇌ Cd − 0,40 3+ − 2+ Cr +e ⇌ Cr − 0,41 2+ Fe + 2e− ⇌ Fe − 0,44 3+ − Cr + 3e ⇌ Cr − 0,74 2+ Zn + 2e− ⇌ Zn − 0,76 2H2O + 2e− ⇌ H2(g) + 2OH− − 0,83 2+ − Cr + 2e ⇌ Cr − 0,91 2+ Mn + 2e− ⇌ Mn − 1,18 3+ − Aℓ + 3e ⇌ Aℓ − 1,66 2+ Mg + 2e− ⇌ Mg − 2,36 + − Na + e ⇌ Na − 2,71 2+ Ca + 2e− ⇌ Ca − 2,87 2+ − Sr + 2e ⇌ Sr − 2,89 2+ Ba + 2e− ⇌ Ba − 2,90 + - Cs + e ⇌ Cs - 2,92 + − K +e ⇌ K − 2,93 + Li + e− ⇌ Li − 3,05 Copyright Reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2 FS September 2014 PREPARATORY EXAMINATION TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD-REDUKSIEPOTENSIALE Half-reactions / Halfreaksies E θ (V) + Li + e− ⇌ Li − 3,05 + K + e− ⇌ K − 2,93 + − Cs + e ⇌ Cs − 2,92 2+ Ba + 2e− ⇌ Ba − 2,90 2+ − Sr + 2e ⇌ Sr − 2,89 2+ Ca + 2e− ⇌ Ca − 2,87 + − Na + e ⇌ Na − 2,71 2+ Mg + 2e− ⇌ Mg − 2,36 3+ − Aℓ + 3e ⇌ Aℓ − 1,66 2+ Mn + 2e− ⇌ Mn − 1,18 2+ − Cr + 2e ⇌ Cr − 0,91 2H2O + 2e− ⇌ H2(g) + 2OH− − 0,83 2+ − Zn Increasing oxidising ability / Toenemende oksiderende vermoë Zn + 2e − 0,76 Increasing reducing ability / Toenemende reduserende vermoë ⇌ 3+ Cr + 3e− ⇌ Cr − 0,74 2+ Fe + 2e− ⇌ Fe − 0,44 3+ − 2+ Cr +e ⇌ Cr − 0,41 2+ Cd + 2e− ⇌ Cd − 0,40 2+ − Co + 2e ⇌ Co − 0,28 2+ Ni + 2e− ⇌ Ni − 0,27 2+ − Sn + 2e ⇌ Sn − 0,14 2+ Pb + 2e− ⇌ Pb − 0,13 3+ − Fe + 3e ⇌ Fe − 0,06 + 2H + 2e− ⇌ H2(g) 0,00 + S + 2H + 2e− ⇌ H2S(g) + 0,14 4+ − 2+ Sn + 2e ⇌ Sn + 0,15 2+ + Cu + e− ⇌ 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 3+ 2+ Fe + e− ⇌ Fe + 0,77 − + NO 3 + 2H + e− ⇌ NO2(g) + H2O + 0,80 + − Ag + e ⇌ Ag + 0,80 2+ − Hg + 2e ⇌ Hg(ℓ) + 0,85 − + NO 3 + 4H + 3e− ⇌ NO(g) + 2H2O + 0,96 − − Br2(ℓ) + 2e ⇌ 2Br + 1,07 2+ Pt + 2 e− ⇌ Pt + 1,20 + 2+ MnO2 + 4H + 2e− ⇌ Mn + 2H2O + 1,23 + − O2(g) + 4H + 4e ⇌ 2H2O + 1,23 2− + 3+ Cr2O 7 + 14H + 6e− ⇌ 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 3+ − 2+ Co +e ⇌ Co + 1,81 F2(g) + 2e− ⇌ 2F− + 2,87 Copyright Reserved