Physical Sciences Grade 12 P2 Mpumalanga Prelim 2024 QP

Downloaded from hlayiso.com ————————————————————— DEPARTMENT OF EDUCATION ————————————————————— DEPARTEMENT VAN ONDERWYS ————————————————————— LEFAPHA LA THUTO ————————————————————— ISEBE LEZEMFUNDO ————————————————————— PROVINSIALE VOORBEREIDENDE EKSAMEN/ PROVINCIAL PREPARATORY EXAMINATION GRAAD/GRADE 12 FISIESE WETENSKAPPE/PHYSICAL SCIENCES VRAESTEL/PAPER 2 (FISIKA/PHYSICS) CHEMIE/CHEMISTRY SEPTEMBER 2024 PUNTE/MARKS: 150 TYD/TIME: 3 uur/hours Hierdie vraestel bestaan uit 15 bladsye en 4 gegewensblaaie./ This question paper consists of 15 pages and 4 data sheets. Kopiereg voorbehou/Copyright reserved Blaai om asseblief/Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 2 September 2024 INSTRUCTIONS AND INFORMATION 1. Write your name 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 may use appropriate mathematical instruments. 8. Show ALL formulae and substitutions in ALL calculations. 9. Round off your FINAL numerical answers to a minimum of TWO decimal places. 10. Give brief motivations, discussions, etc. where required. 11. You are advised to use the attached DATA SHEETS. 12. Write neatly and legibly. Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 3 September 2024 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various 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–D) next to the question numbers (1.1 to 1.10) in the ANSWER BOOK, e.g. 1.11 E. 1.1 Which ONE of the following compounds is a ketone? A CH3COCH2CH3 B CH3COOCH2CH3 C CH3CH2CH2CHO D CH3CH(OH)CH2CH3 (2) 1.2 Consider the flow diagram below that represents an organic reaction: Compound X HBr 2-bromo-3-methylbutane The IUPAC name of compound X is: A 2-methylbutane B 3-methylbutane C 2-methylbut-3-ene D 3-methylbut-2-ene (2) 1.3 Which ONE of the following pairs of reactants can be used to prepare ethyl propanoate in the laboratory? A Ethane and propanoic acid B Propanol and ethanoic acid C Ethanol and propanoic acid D Ethene and propanol (2) 1.4 Which ONE of the following compounds will enable butan-2-ol to undergo an elimination reaction? A Concentrated HCℓ B Concentrated H2SO4 C Diluted HNO3 D Diluted NaOH (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 4 September 2024 1.5 When zinc (II) carbonate reacts with excess hydrochloric acid, carbon dioxide is produced. The graphs below were obtained under two different reaction conditions. Volume of CO2 (cm3) R S Time (s) The change in the graph from S to R could be brought about by … A decreasing the concentration of the acid. B increasing the mass of the zinc (II) carbonate. C decreasing the particle size of the zinc (II) carbonate. D adding a catalyst. (2) 1.6 The reaction represented by the balanced equation below reaches equilibrium in a closed container. H2(g) + I2(g) ⇌ 2HI(g) ∆H < 0 How will the equilibrium be affected if the volume of the container is increased at constant temperature and then the temperature is increased at constant volume? EFFECT OF INCREASE EFFECT OF INCREASE IN IN VOLUME TEMPERATURE Reverse reaction A No effect is favoured Reverse reaction Reverse reaction B is favoured is favoured Forward reaction C No effect is favoured Reverse reaction Forward reaction D is favoured is favoured (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 5 September 2024 1.7 Nitric acid is titrated with an ammonium hydroxide solution. The EQUIVALENCE POINT is the point in the titration where … A the concentration of the indicator changes. B nacid = nbase. C [H3O+] = [OH−]. D the pH = 7. (2) 1.8 Consider the equation: H2O + A → OH- + H2SO4 The reactant A represents a/an: A base having the formula HSO4- B acid having the formula HSO4- C base having the formula SO42- D acid having the formula SO42- (2) 1.9 Consider the following chemical reactions: REACTION X: Pb(s) → Pb2+(aq) + 2e- REACTION Y: 4H+(aq) + O2(g) + 4e- → 2H2O(ℓ) Which ONE of the following combinations is CORRECT for reaction X and Y? REACTION X REACTION Y A Pb is reduced O2 is oxidised B Pb is oxidised H+ is reduced C Pb is oxidised O2 is reduced D Pb is reduced H+ is oxidised (2) 1.10 Which ONE of the following CORRECTLY shows the gases produced at the different electrodes during the electrolysis of a concentrated solution of sodium chloride? CATHODE ANODE A Hydrogen gas Chlorine gas B Chlorine gas Water vapour C Oxygen gas Chlorine gas D Chlorine gas Hydrogen gas (2) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 6 September 2024 QUESTION 2 (Start on a new page.) The letters A to F in the table below represent six organic compounds. A CH3CH2COOCH3 D CH3CHCHCH2CH3 H H C H H H O H O H C C C C C H B E H C CH2 CH3 H H H H C H H C H H C 2-fluoro-3,4-dimethylhexane F Butanoic acid Write down the: 2.1 LETTER of the compound that belongs to the halo-alkanes (1) 2.2 STRUCTURAL FORMULA of the functional group of compound F (1) 2.3 LETTER of the compound that represents an unsaturated hydrocarbon (1) 2.4 NAME of the functional group of compound E (1) 2.5 NAME of the inorganic acid needed to prepare compound A (1) 2.6 LETTER of the compound that represents an aldehyde (1) 2.7 Empirical formula of compound A (1) 2.8 STRUCTURAL FORMULA of compound C (3) 2.9 IUPAC NAME of compound B (2) 2.10 LETTERS of the compounds that are FUNCTIONAL isomers of each other (1) [13] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 7 September 2024 QUESTION 3 (Start on a new page.) An investigation was carried out to determine the relationship between the boiling point of different alkanes and one of their structural isomers. The results obtained are shown in the table below: BOILING BOILING NAME ISOMER POINT (°C) POINT (°C) A ethane -88,5 B butane -1 E methyl propane -12 C pentane 34 F 2-methylbutane 28 D hexane 68,7 G 2,3-dimethylbutane 58 3.1 Define the term structural isomer. (2) 3.2 What TYPE of isomerism is used during this investigation? (1) 3.3 Explain the difference in boiling points between butane and its isomer methyl propane. (3) 3.4 Consider compounds A to D. For this part of the investigation, write down the: 3.4.1 Control variable (1) 3.4.2 Independent variable (1) 3.4.3 Which ONE of compounds A to D has the highest vapour pressure? Explain the answer by referring to the intermolecular forces and the energy. (3) 3.5 Write down a conclusion for this investigation. (2) 3.6 Use molecular formulae to write down a balanced chemical equation for the combustion of pentane. (3) [16] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 8 September 2024 QUESTION 4 (Start on a new page.) Study the flow diagram of various organic reactions and answer the questions that follow. Reaction I Compound A Butene Propane + Reaction II H2(g) Compound B Reaction III 2-chlorobutane Reaction V Reaction IV Compound C 2-butanol 4.1 For reaction I, write down the: 4.1.1 TYPE of the reaction (1) 4.1.2 IUPAC NAME of compound A (2) 4.2 Consider reaction II and write down the: 4.2.1 TYPE of the reaction (1) 4.2.2 IUPAC NAME of organic compound B (1) 4.2.3 NAME of a suitable catalyst (1) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 9 September 2024 4.3 Write down the TYPE of reaction represented by reaction III. (1) 4.4 Reaction IV is an elimination reaction. Write down the: 4.4.1 TYPE of elimination reaction (1) 4.4.2 Reaction conditions (2) 4.4.3 Balanced chemical equation for the formation of compound C, using STRUCTURAL FORMULAE (5) 4.5 Consider reaction V. Write down the: 4.5.1 NAME or FORMULA of the inorganic reactant needed (1) 4.5.2 Type of alcohol represented by 2-butanol Choose from PRIMARY, SECONDARY or TERTIARY. Give a reason for the answer. (2) [18] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 10 September 2024 QUESTION 5 (Start on a new page.) The reaction of magnesium (Mg) and EXCESS diluted hydrochloric acid (HCℓ) is used to investigate some factors affecting the reaction rate. The balanced equation for the reaction is: Mg(s) + 2HCℓ(ℓ) → MgCℓ2(aq) + H2(g) The table below summarises the reaction conditions. EXPERIMENT STATE of Mg MASS of Mg TEMPERATURE (°C) 1 ribbon x 25 2 powder x 25 3 powder ½x 20 5.1 Define the term reaction rate. (2) 5.2 Which experiment will have the highest reaction rate? Choose from EXPERIMENT 1, EXPERIMENT 2 or EXPERIMENT 3. (1) 5.3 Use the collision theory to explain the answer to QUESTION 5.2. (2) 5.4 Besides temperature, write down ONE other way to increase the reaction rate in EXPERIMENT 2. (1) The mass of gas produced in EXPERIMENT 2 is obtained by measuring the loss in mass of the flask and its contents at one-second intervals. Z Hydrochloric acid solution Gas bubbles Magnesium powder Balance Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 11 September 2024 The results of this experiment is displayed in the graph below. Mass of H2 (g) 3,5 2,8 1 2 3 4 5 6 Time (s) 5.5 Write down the name of apparatus Z. (1) 5.6 Give a reason why this experimental setup cannot be classified as a closed system. (1) 5.7 Calculate the AVERAGE RATE (in g·s-1) of this reaction during the first four seconds. (2) 5.8 Write down the loss in mass of the flask and its contents. (1) 5.9 Use the graph to calculate the mass of magnesium powder (x) used in EXPERIMENT 2. (5) 5.10 Why is the magnesium in EXPERIMENT 2 the limiting reagent? (1) 5.11 Redraw the graph given in your ANSWER BOOK and name it Graph 2. On the same set of axes, draw the graph for EXPERIMENT 3 and label this Graph 3. (2) [19] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 12 September 2024 QUESTION 6 (Start on a new page.) The table below shows the effect of temperature changes on the value of the equilibrium constant (Kc) when the following reaction takes place in a closed container of volume 500 cm3. 2NO2(g) ⇌ N2O4(g) (brown gas) (colourless gas) TEMPERATURE (K) Equilibrium constant (Kc) 300 1 x101 400 3 x 10-2 500 1 x 10-3 600 1 x 10-4 700 8,33 x 10-5 6.1 Define the term chemical equilibrium. (2) 6.2 Which colour will be seen at 300 K? Choose from BROWN, COLOURLESS or LIGHT BROWN. (1) 6.3 Is the forward reaction exothermic or endothermic? Explain the answer. (3) 6.4 X g of NO2 is sealed in the container at 300 K. At equilibrium, the concentration of N2O4 was 3 mol∙dm3. Calculate X. (8) 6.5 How will an increase in the reactant (NO2) at 700 K effect the rate of the reverse reaction? Choose from INCREASES, DECREASES or STAYS THE SAME. (1) 6.6 The pressure on the system is increased by decreasing the volume of the container at 300 K. How will this change affect the: 6.6.1 Value of KC? Choose from INCREASES, DECREASES or REMAINS THE SAME. Give a reason for the answer. (2) 6.6.2 Concentration of the products? Choose from INCREASES, DECREASES or REMAINS THE SAME. Explain the answer using Le Chatelier's principle. (3) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 13 September 2024 QUESTION 7 (Start on a new page.) 7.1 Hydrofluoric acid (HF) is a weak acid.. 7.1.1 Define the term weak acid. (2) 7.1.2 A sample of hydrofluoric acid has a pH of 4,5 at 25 °C. Calculate the concentration of the hydronium ions (H3O+(aq)) in the sample. (3) When hydrofluoric acid reacts with sodium hydroxide, sodium fluoride is formed. 7.1.3 Will the pH of the sodium fluoride solution be GREATER THAN 7, SMALLER THAN 7 or EQUAL TO 7? Give a reason for the answer. (2) 7.2 In REACTION A, 3,5 g of pure MgCO3(s) reacted completely in 50 cm3 of HCℓ. The balanced equation for the reaction is given below: REACTION A: MgCO3 + 2HCℓ → MgCℓ2 + CO2 + H2O The EXCESS HCℓ neutralises exactly 20 cm3 of a NaOH solution with a concentration of 1,2 mol∙dm-3 in REACTION B. REACTION B: HCℓ + NaOH → NaCℓ + H2O 7.2.1 Calculate the number of moles of HCℓ reacted in REACTION A. (3) 7.2.2 Calculate the concentration of the original solution of HCℓ. (6) [16] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 14 September 2024 QUESTION 8 (Start on a new page.) The diagram below represents a galvanic cell functioning under standard conditions with magnesium and iron as electrodes. The nett cell equation for this cell is: 2Fe3+(aq) + 3Mg(s) → 2Fe(s) + 3Mg2+(aq) V Mg Fe Mg2+(aq) Fe3+(aq) KCℓ 8.1 For this cell, write down: 8.1.1 The energy conversion that takes place (1) 8.1.2 TWO standard conditions (2) 8.1.3 The electrode which acts as the CATHODE Give a reason for the answer. (2) 8.1.4 The oxidation half-reaction (2) 8.1.5 The cell notation (3) 8.1.6 The NAME of the component responsible for electrical neutrality of the half cells (1) 8.2 Calculate the initial EMF of the cell. (4) [15] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 15 September 2024 QUESTION 9 (Start on a new page.) In the electrolytic cell represented below, two CARBON RODS, P and Q, are used as electrodes and concentrated copper (II) chloride solution is used as electrolyte. P Q CuCℓ2(aq) 9.1 Define the term electrolysis. (2) 9.2 What observation can be made at electrode P while the cell is operating? (1) 9.3 Write down the half-reaction that takes place at electrode Q. (2) 9.4 Write down the NAME or FORMULA of the reducing agent in this reaction. (1) 9.5 What is the function of CuCℓ2(aq) as electrolyte in this cell? (1) This cell is now used for the refining of copper. 9.6 Which electrode (P or Q) will have to be replaced with pure copper during the refining process? Give a reason for the answer. (2) 9.7 Explain why the concentration of the ions in the solution remains constant. (1) 9.8 Silver and platinum are formed at the bottom of the container during the refining process of impure copper. Refer to the relative strength of the reducing agents to explain why these two metals do not form ions. (3) [13] TOTAL: 150 Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences/P2/Grade 12 1 September 2024 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 Standaarddruk p 1,013 x 105 Pa Molar gas volume at STP Vm 22,4 dm3∙mol-1 Molêre gasvolume by STD Standard temperature T 273 K Standaardtemperatuur Charge on electron e -1,6 x 10-19 C Lading op 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/of c n V MV Vm c a v a na  pH = -log[H3O+] cbvb nb Kw = [H3O+][OH-] = 1 x 10-14 at/by 298 K Eθcell  Eθcathode  Eθanode / Eθsel  Ekatode θ  Eθanode or/of Eθcell  Ereduction θ  Eθoxidation / Eθsel  Ereduksie θ  Eθoksidasie or/of Eθcell  Eθoxidisingagent  Ereducing θ agent / Esel  Eoksideermiddel  Ereduseermiddel θ θ θ Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 2 September 2024 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 Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 3 September 2024 TABLE 4A: STANDARD REDUCTION POTENTIALS TABEL 4A: STANDAARD-REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E (V) F2(g) + 2e ⇌ 2F + 2,87 Co3+ + e ⇌ Co2+ + 1,81 H2O2 + 2H+ +2e ⇌ 2H2O +1,77  MnO 4 + 8H+ + 5e ⇌ Mn2+ + 4H2O + 1,51 Cℓ2(g) + 2e ⇌ 2Cℓ  + 1,36 2  Cr2O 7 + + 14H + 6e ⇌ 2Cr3+ + 7H2O + 1,33 Increasing strength of oxidising agents/Toenemende sterkte van oksideermiddels Increasing strength of reducing agents/Toenemende sterkte van reduseermiddels O2(g) + 4H+ + 4e ⇌ 2H2O + 1,23 MnO2 + 4H+ + 2e ⇌ Mn2+ + 2H2O + 1,23 Pt2+ + 2e ⇌ Pt + 1,20 Br2(ℓ) + 2e ⇌ 2Br + 1,07 NO 3 + 4H+ + 3e  ⇌ NO(g) + 2H2O + 0,96 Hg2+ + 2e ⇌ Hg(ℓ) + 0,85 Ag+ + e ⇌ Ag + 0,80 NO 3 + 2H+ + e  ⇌ NO2(g) + H2O + 0,80 Fe3+ + e ⇌ Fe2+ + 0,77 O2(g) + 2H+ + 2e ⇌ H2O2 + 0,68 I2 + 2e ⇌ 2I + 0,54 Cu+ + e ⇌ Cu + 0,52 SO2 + 4H+ + 4e ⇌ S + 2H2O + 0,45 2H2O + O2 + 4e ⇌ 4OH + 0,40 Cu2+ + 2e ⇌ Cu + 0,34 2 SO 4 + 4H+ + 2e ⇌ SO2(g) + 2H2O + 0,17 Cu2+ + e ⇌ Cu+ + 0,16 Sn4+ + 2e ⇌ Sn2+ + 0,15 S + 2H+ + 2e ⇌ H2S(g) + 0,14 2H+ + 2e ⇌ H2(g) 0,00 Fe3+ + 3e ⇌ Fe  0,06 Pb2+ + 2e ⇌ Pb  0,13 Sn2+ + 2e ⇌ Sn  0,14 Ni2+ + 2e ⇌ Ni  0,27 Co2+ + 2e ⇌ Co  0,28 Cd2+ + 2e ⇌ Cd  0,40 Cr3+ + e ⇌ Cr2+  0,41 Fe2+ + 2e ⇌ Fe  0,44 Cr3+ + 3e ⇌ Cr  0,74 Zn2+ + 2e ⇌ Zn  0,76 2H2O + 2e ⇌ H2(g) + 2OH  0,83 Cr2+ + 2e ⇌ Cr  0,91 Mn2+ + 2e ⇌ Mn  1,18 Aℓ3+ + 3e ⇌ Aℓ  1,66 Mg2+ + 2e ⇌ Mg  2,36 Na+ + e ⇌ Na  2,71 Ca2+ + 2e ⇌ Ca  2,87 Sr2+ + 2e ⇌ Sr  2,89 Ba2+ + 2e ⇌ Ba  2,90 Cs+ + e- ⇌ Cs  2,92 K+ + e ⇌ K  2,93 Li+ + e ⇌ Li  3,05 Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 4 September 2024 TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD-REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E (V) Li+ + e ⇌ Li  3,05 K+ + e ⇌ K  2,93 Cs+ + e- ⇌ Cs  2,92 Ba2+ + 2e ⇌ Ba  2,90 Sr2+ + 2e ⇌ Sr  2,89 Ca2+ + 2e ⇌ Ca  2,87 Na+ + e ⇌ Na  2,71 Increasing strength of oxidising agents/Toenemende sterkte van oksideermiddels Increasing strength of reducing agents/Toenemende sterkte van reduseermiddels Mg2+ + 2e ⇌ Mg  2,36 Aℓ3+ + 3e ⇌ Aℓ  1,66 Mn2+ + 2e ⇌ Mn  1,18 Cr2+ + 2e ⇌ Cr  0,91 2H2O + 2e ⇌ H2(g) + 2OH  0,83 Zn2+ + 2e ⇌ Zn  0,76 Cr3+ + 3e ⇌ Cr  0,74 Fe2+ + 2e ⇌ Fe  0,44 Cr3+ + e ⇌ Cr2+  0,41 Cd2+ + 2e ⇌ Cd  0,40 Co2+ + 2e ⇌ Co  0,28 Ni2+ + 2e ⇌ Ni  0,27 Sn2+ + 2e ⇌ Sn  0,14 Pb2+ + 2e ⇌ Pb  0,13 Fe3+ + 3e ⇌ Fe  0,06 2H+ + 2e ⇌ H2(g) 0,00 S + 2H+ + 2e ⇌ H2S(g) + 0,14 Sn4+ + 2e ⇌ Sn2+ + 0,15 Cu2+ + e ⇌ Cu+ + 0,16 2 SO 4 + 4H+ + 2e ⇌ SO2(g) + 2H2O + 0,17 Cu2+ + 2e ⇌ Cu + 0,34 2H2O + O2 + 4e ⇌ 4OH + 0,40 SO2 + 4H+ + 4e ⇌ S + 2H2O + 0,45 Cu+ + e ⇌ Cu + 0,52 I2 + 2e ⇌ 2I + 0,54 O2(g) + 2H+ + 2e ⇌ H2O2 + 0,68 Fe3+ + e ⇌ Fe2+ + 0,77 NO 3 + 2H+ + e  ⇌ NO2(g) + H2O + 0,80 Ag+ + e ⇌ Ag + 0,80 Hg2+ + 2e ⇌ Hg(ℓ) + 0,85 NO 3 + 4H+ + 3e  ⇌ NO(g) + 2H2O + 0,96 Br2(ℓ) + 2e ⇌ 2Br + 1,07 Pt2+ + 2e ⇌ Pt + 1,20 MnO2 + 4H+ + 2e ⇌ Mn2+ + 2H2O + 1,23 O2(g) + 4H+ + 4e ⇌ 2H2O + 1,23 2 Cr2O 7 + 14H+ + 6e ⇌ 2Cr3+ + 7H2O + 1,33 Cℓ2(g) + 2e ⇌ 2Cℓ + 1,36  MnO 4 + 8H+ + 5e ⇌ Mn2+ + 4H2O + 1,51 H2O2 + 2H+ +2e ⇌ 2H2O +1,77 Co3+ + e ⇌ Co2+ + 1,81 F2(g) + 2e ⇌ 2F + 2,87 Copyright reserved