Physical Sciences Grade 12 P2 Gauteng Mock 2014 QP (Eng)

Downloaded from hlayiso.com GAUTENG DEPARTMENT OF EDUCATION PREPARATORY EXAMINATION 2014 10842 PHYSICAL SCIENCES SECOND PAPER MARKS: 150 Pages 19 TIME: 3 hours 3 P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 2 (Second Paper) 10842/14 GAUTENG DEPARTMENT OF EDUCATION PREPARATORY EXAMINATION PHYSICAL SCIENCES (Second Paper) TIME: 3 hours MARKS: 150 INSTRUCTIONS AND INFORMATION: 1. Write your name in the appropriate space 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, for example between QUESTION 2.1 and QUESTION 2.2. 6. You may use a non-programmable calculator. 7. You may use appropriate mathematical instruments. 8. You are advised to use the attached DATA SHEETS. 9. Show ALL formulae and substitutions in ALL calculations. 10. Round off your final numerical answers to a minimum of TWO decimal places. 11. Give brief motivations, discussions, et cetera where required. 12. Write neatly and legibly. P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 3 (Second Paper) 10842/14 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Four options are given 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 (1.1–1.10) in the ANSWER BOOK. 1.1 An example of an unsaturated hydrocarbon is: A C2HCℓ3 B C4H8 C C3H8 D C3H7OH (2) 1.2 The semi-condensed structural formula of an organic compound is shown below: CH3 | CH2 H CH3 H | | | | H3C — C — C — C — C — H | | | | CH3 H H H What is the correct IUPAC name for this organic compound? A 2,4,4-trimethylhexane B 2-ethyl-2,4-dimethylpentane C 2,4-dimethyl-4-ethylpentane D 3,3,5-trimethylhexane (2) 1.3 A simple organic reaction is given below: H H C H H + HCℓ X C C H H Which one of the formulae below represents the major organic product X formed in this reaction? A CH3CHCℓCH2Cℓ B CH2CℓCH2CH3 C CH3CHCℓCH3 D CH3CH2CH2Cℓ (2) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 4 (Second Paper) 10842/14 1.4 A chemical reaction is in a state of dynamic equilibrium when the ... A reactants and products always have the same masses. B concentration of products is zero. C equilibrium constant is zero. D forward and reverse reactions occur at the same rate. (2) 1.5 The Maxwell-Boltzmann energy distribution curves below show the number of particles as a function of their kinetic energy for a reaction, at four different temperatures. The minimum kinetic energy needed for effective collisions to take place is represented by E. Which one of the curves represents the reaction that takes place at the highest temperature? I II III IV A I B II C III D IV (2) 1.6 Consider the following potential energy diagram for a chemical reaction. Which arrow indicates the activation energy of the forward reaction? The activation energy of the forward reaction is: A A B B C C D D (2) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 5 (Second Paper) 10842/14 1.7 The pH of a solution of NaOH is 10,5. Which one of the following statements is CORRECT? A [OH-] = [H3O+] B [Na+] > [OH-] C [H3O+] < [OH-] D [OH-] < [H3O+] (2) 1.8 The oxidation number of sulphur in a sulphate (SO42-) ion is … A +8. B +6. C +4. D +2. (2) 1.9 Consider the following chemical reactions: Reaction X: Fe(s) → Fe2+ (aq) + 2e- Reaction Y: 4H+ (aq) + O2 (g) + 4e-→ 2H20(ℓ) Which one of the following statements is CORRECT for reaction X and Y? Reaction X Reaction Y A Fe is oxidised H+ is reduced B Fe is reduced O2 is oxidised C Fe is oxidised O2 is reduced D Fe is reduced H+ is oxidised (2) 1.10 In industry, nitrogen gas is prepared by the following process: A Fractional distillation B Contact process C Ostwald process D Haber process (2) [20] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 6 (Second Paper) 10842/14 QUESTION 2 (Start on a new page) Consider the following compounds and answer the questions below: A B H H H H H H C H C O H C C C H C H C H H O H H H H C D CH3 H H3C HC H O C H CH CH2 C H H H3C C C H CH3 E F H H Cl C C H H H 2.1.1 To which homologous series does compound F belong? (1) 2.1.2 Which compound is an alkyne? (1) 2.1.3 Give the IUPAC name for compound E. (1) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 7 (Second Paper) 10842/14 2.1.4 Compound C is one of the reactants needed to produce compound B. Give the IUPAC NAME for the other reactant needed for the production of compound B. (1) 2.1.5 Write down an equation, using structural formulae to represent the formation of compound B. (4) 2.1.6 Write down the structural formula of a functional isomer of compound F. (2) 2.1.7 Compound A can burn in excess oxygen. Using molecular formulae, write a balanced equation for the reaction. (3) 2.1.8 Name the type of reaction that takes place in QUESTION 2.1.7. (1) 2.2 There are two chain isomers for the organic compound with molecular formula C4H10. 2.2.1 Define the term chain isomer. (2) 2.2.2 Write down the structural formulae of the two chain isomers and also give their IUPAC names. (4) 2.2.3 Which ONE of the isomers mentioned in QUESTION 2.2.2 has the highest boiling point? (1) 2.2.4 Explain the difference in the boiling points of the chain isomers. (3) [24] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 8 (Second Paper) 10842/14 QUESTION 3 (Start on a new page) The flow diagram below shows how organic compounds can be prepared from an unsaturated hydrocarbon, prop–1– ene. Reaction I takes place when prop–1– ene reacts with bromine water. Compound A Reaction I Reaction I Prop – 1 – ene Compound B Reaction II 3.1 Write down: 3.1.1 The name of the type of reaction which takes place in the above Reaction I (1) 3.1.2 The structural formula of compound A (2) 3.1.3 Will Reaction I be spontaneous at room temperature? Answer YES or NO. (1) 3.2 Compound B is formed when prop–1–ene reacts with water in the presence of dilute sulphuric acid. Write down: 3.2.1 the name of the type of reaction which takes place in the above Reaction II (1) 3.2.2 the IUPAC name for compound B (2) 3.2.3 the homologous series to which compound B belongs. (1) 3.3 Cracking is a process used to produce petrol with an octane rating of 98. Such petrol is made up of a 98% saturated hydrocarbon called 2,2,4–trimethylpentane. 3.3.1 Explain what is meant by the term cracking. (2) 3.3.2 Write down the STRUCTURAL FORMULA for 2,2,4–trimethylpentane. (2) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 9 (Second Paper) 10842/14 3.4 The diagram below represents two polymers both formed through addition polymerisation. Molecule A Molecule B 3.4.1 Give the structural formula for the monomer used to make molecule A. (2) 3.4.2 Which of the polymers (A or B) is PVC? (1) 3.4.3 State ONE industrial use of polymer A. (1) [16] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 10 (Second Paper) 10842/14 QUESTION 4 (Start on a new page) The following apparatus was used by a group of learners in an investigation to find out how surface area affects the rate of reaction between solid magnesium metal and 100 cm3 dilute sulphuric acid with a concentration of 1 mol∙dm-3. During the reaction, the gas that forms is collected in the gas syringe which measures the volume of gas produced. The equation for the reaction is: Mg (s) + H2SO4(aq)  MgSO4(aq) + H2 (g) gas syringe 3 100 cm of -3 1 mol·dm of sulphuric acid magnesium ribbon In EXPERIMENT I, 20 g of magnesium, in the form of 5 small pieces, was used. In EXPERIMENT II, 20 g of magnesium, in the form of one big piece was used. The learners performed the experiments and plotted a graph of their results for experiment one, which is represented below. Volume of 3 gas (cm ) Time (s) 4.1 Besides the mass and the volume of the reactants, give ONE other variable that must be kept constant in this investigation (1) 4.2 Name the dependent variable for EXPERIMENT I. (1) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 11 (Second Paper) 10842/14 4.3 Use the graph to calculate the average rate of the reaction (in cm3·s-1) for the first 30 seconds. (3) 4.4 Will the rate of the reaction at 50s be GREATER THAN, LESS THAN or EQUAL TO that rate calculated in QUESTION 4.3? (1) 4.5 Give a reason for your answer in QUESTION 4.4. (1) 4.6 Predict how the gradient of EXPERIMENT II results would compare to EXPERIMENT I plotted above. Write only INCREASE, DECREASE or NO CHANGE. (1) 4.7 Use the collision theory to explain how the increase in surface area of the magnesium metal affects the rate of the reaction. (3) 4.8 Calculate the mass of magnesium metal that remains after the reaction has stopped. (5) 4.9 Catalytic converters are substances that are coated onto surfaces of car exhausts to act as positive catalysts. Define a positive catalyst. (2) [18] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 12 (Second Paper) 10842/14 QUESTION 5 (Start on a new page) When a number of moles of X2 (g) and Y2 (g) are placed in an empty, closed 2 dm3 container at 800 °C , a reaction takes place and eventually reaches equilibrium according to the following equation: X2(g) + 3Y2(g) ⇌ 2XY3(g) At equilibrium there is 0,4 mol∙dm-3 of Y2 and XY3 present. You are also given the following information for the reaction: Temperature °C Kc 400 0,8 600 2,5 800 4,0 5.1 Calculate the initial number of moles of X2 and Y2 placed in the container. (9) 5.2 Is the forward reaction endothermic or exothermic? (1) 5.3 Explain your answer to QUESTION 5.2. (2) 5.4 What effect will adding more Y2 (g) at 800°C have on the following? Answer only INCREASE, DECREASE OR STAY THE SAME. 5.4.1 The rate of the reverse reaction (1) 5.4.2 Concentration of X2 (g) (1) 5.5 Which ONE of the following gases XY3 or X2 would be present in a higher concentration in the equilibrium mixture at 400°C? (1) 5.6 Explain your answer to QUESTION 5.5. (2) [17] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 13 (Second Paper) 10842/14 QUESTION 6 (Start on a new page) You are given the following ionisation reaction of ethanoic acid in water: CH3COOH (aq) ⇌ CH3COO- (aq) + H+ (aq) Ka=1,8 x 10-5 6.1 What does the ionisation constant indicate about the strength of the acid? (1) 6.2 What is meant by a concentrated acid? (2) 6.3 H2PO4- is an ampholyte. Write an equation to indicate its role as a base. (2) 6.4 Write down a conjugate acid/base pair from your equation in QUESTION 6.3. (1) 6.5 Milk of Magnesia has been used over the ages to relieve stomach ailments caused by excess stomach acid. The active ingredient in Milk of Magnesia is magnesium hydroxide (Mg(OH)2). A group of learners prepare a solution of magnesium hydroxide. 6.5.1 What mass of Mg(OH)2 must be dissolved in distilled water to prepare 500 cm3 of a solution with a concentration of 0,20 mol∙dm-3? (5) 6.5.2 What will the concentration of the hydroxide ions in the solution be? Assume 100% dissociation of magnesium hydroxide in water. (2) 6.5.3 The pH of any medicine safe for human consumption must lie between pH = 4 and pH =9. Will this solution that the learners prepare be safe for human consumption? Show all calculations. (5) 6.6 The learners now check the concentration of their solution that they made. They run a titration using hydrochloric acid of concentration 0,1 mol∙dm-3 . They transfer 25 cm3 of the magnesium hydroxide solution into a conical flask. The balanced chemical equation for this reaction is: Mg(OH)2 (aq) + 2HCℓ (aq) MgCℓ2 (aq) + 2 H20(ℓ) Determine what volume of HCℓ will be needed to fully neutralise the Milk of Magnesia if the concentration is actually 0,2 mol∙dm-3. (4) [22] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 14 (Second Paper) 10842/14 QUESTION 7 (Start on a new page) Aluminium oxide is an ionic compound. It is found in the earth’s crust as an ore called bauxite. In order to obtain aluminium, the aluminium oxide is melted and then electricity is passed through it. anode - - + + + cathode bauxite plus cryolite (melt) - molten aluminium 7.1 Define the term electrolytic cell. (2) 7.2 Write down the NAMES or FORMULAE of the ions present in the melt. (2) 7.3 Write down the half reaction that occurs at the anode. (2) 7.4 Write down the half reaction that occurs at the cathode. (2) 7.5 Calculate the cell potential for this electrolytic cell if the reaction occurring at the anode has an electrode potential of -0,56 V. (4) 7.6 Explain why the anodes have to be replaced on a regular basis. (1) [13] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES 15 (Second Paper) 10842/14 QUESTION 8 (Start on a new page) The equations A and B below represent two redox reactions. A: 2Aℓ2O3 (s) + 3C (s) → 4Aℓ (ℓ) + 3CO2 (g) B: Zn(s) + 2Ag+(aq) ⇌ Zn2+ (aq) + 2Ag (s) 8.1 Define oxidation in terms of electron transfer. (2) 8.2 Write down the FORMULA of the substance which is: 8.2.1 Reduced in reaction A. (1) 8.2.2 The reducing agent in reaction B. (1) 8.3 A Zn-Ag cell has a cell potential difference of 1,56 V under standard conditions. The cell is allowed to run for 3 hours and the cell potential drops to 1,45 V. Using Le Chatelier’s principle, explain the drop in potential difference. (3) 8.4 For reaction A, write down the half-reaction at cathode. (2) 8.5 What type of energy conversion occurs in a galvanic cell? (1) [10] QUESTION 9 (Start on a new page) In the CONTACT process for the manufacture of sulphuric acid the second step of the process produces sulphur (VI) oxide as in the following equation: 2SO2(g) + O2 (g) ⇌ 2 SO3 (g) H = -197 kJ·mol-1 The rate of the formation of SO3 is increased in a number of ways using rate and equilibrium principles. 9.1 Name the catalyst used in the Contact Process. (1) 9.2 Ammonia compounds are necessary for the production of fertiliser. It is manufactured in the Haber process. Give a balanced equation for the Haber process. (3) 9.3 Calculate the number of moles of nitrogen in a bag of fertiliser that has a ratio of 7:1:3 (22). The mass of the bag is 5 kg. (5) 9.4 The abuse of large amounts of fertiliser can result in the enrichment of inorganic plant nutrients in water sources. Explain how this leads to dead and decaying plant material. (1) [10] TOTAL FOR SECTION B: 130 TOTAL: 150 END

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Downloaded from hlayiso.com PHYSICAL SCIENCES 16 (Second Paper) 10842/14 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 Avogadro's constant NA 6,02 x 1023 mol-1 Avogadro-konstante Standard pressure p 1,013 x 105 Pa Standaarddruk Molar gas volume at STP Vm 22,4 dm3∙mol-1 Molêre gasvolume by STD Standard temperature Standaardtemperatuur T 273 K Charge on electron e -1,6 x 10-19 C Lading op elektron TABLE 2: FORMULAE/TABEL 2: FORMULES m N n n M NA V n m n c or/of c Vm V MV pH = -log[H3O+] Kw = [H3O+][OH-] = 1 x 10-14 at/by 298 K CaVa na  CbVb nb Eθcell  Eθcathode  Eθanode / Eθsel  Ekatode θ  Eθanode or/of Eθcell  Ereduction θ  Eθoxidation / Eθsel  Ereduksie θ  Eθoksidasie or/of Eθcell  Eθoxidisingagent  Ereducing θ agent / E sel  Eoksideermiddel  Ereduseermiddel θ θ θ

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Downloaded from hlayiso.com PHYSICAL SCIENCES / (Second Paper) 10842/14 17 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) (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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Downloaded from hlayiso.com PHYSICAL SCIENCES 18 (Second Paper) 10842/14 ABLE 4A: STANDARD REDUCTION POTENTIALS / TABEL 4A: STANDAARD REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E θ (V) F2(g) + 2e ⇌ 2F + 2,87 Co + e 2+ 3+ ⇌ Co + 1,81 Increasing reducing ability/Toenemende reduserende vermoë H2O2 + 2H +2e ⇌ + 2H2O + 1,77  MnO 4 + 8H + 5e 2+ + ⇌ Mn + 4H2O + 1,51 Increasing oxidising ability/Toenemende oksiderende vermoë  Cℓ2(g) + 2e ⇌ 2Cℓ + 1,36 2 Cr2O 7 + 14H + 6e 3+ + ⇌ 2Cr + 7H2O + 1,33  + 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 ⇌ + NO(g) + 2H2O + 0,96 Hg + 2e ⇌ 2+ Hg(ℓ) + 0,85 Ag + e ⇌ + Ag + 0,80  NO 3 + 2H + e ⇌ + NO2(g) + H2O + 0,80  2+ Fe + e 3+ ⇌ 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 Cu + 2e ⇌ 2+ Cu + 0,34 2 SO 4 + 4H + 2e ⇌ + SO2(g) + 2H2O + 0,17 Cu + e + 2+ ⇌ 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

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Downloaded from hlayiso.com PHYSICAL SCIENCES 19 (Second Paper) 10842/14 TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E θ (V)  ⇌  3,05 + Li + e Li Increasing reducing ability/Toenemende reduserende vermoë K + e Increasing oxidising ability/Toenemende oksiderende vermoë ⇌  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 Cd + 2e ⇌  0,40 2+ Cd Co + 2e ⇌  0,28 2+ 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  Cu + 2e 2+ ⇌ 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 Fe + e 2+ 3+ ⇌ 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 + 14H + 6e 3+ Cr2O 7 + ⇌ 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