Physical Sciences Grade 12 P2 Eastern Cape Mock 2014 QP

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 SEPTEMBER 2014 PHYSICAL SCIENCES P2 MARKS: 150 TIME: 3 hours *PHSCE2* This question paper consists of 14 pages and 4 data sheets.

Downloaded from hlayiso.com 2 PHYSICAL SCIENCES P2 (SEPTEMBER 2014) INSTRUCTIONS AND INFORMATION 1. Write your full NAME and SURNAME in the appropriate spaces on the ANSWER BOOK. 2. Answer ALL the questions. 3. This question paper consists of TWO sections: SECTION A: 20 marks SECTION B: 130 marks 4. Answer SECTION A and SECTION B in the ANSWER BOOK. 5. Non-programmable calculators may be used. 6. Appropriate mathematical instruments may be used. 7. Number your answers correctly according to the numbering system used in this question paper. 8. You are advised to use the attached data sheets and the periodic table. 9. Wherever motivations, discussions, etc. are required, be brief. 10. Round off your final numerical answers to a minimum of TWO decimal places. Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) PHYSICAL SCIENCES P2 3 SECTION A Answer this section in the ANSWER BOOK. QUESTION 1: MULTIPLE-CHOICE QUESTIONS Four possible options are provided as answers to the following questions. Each question has only ONE correct answer. Write only the correct letter (A–D) next to the question number (1.1–1.10) in the ANSWER BOOK. 1.1 Which ONE of the following compounds will decolourise bromine water the fastest under normal conditions? H H H O H H H H | | | ‖ | | | | C=C H–C–C–H H–C–C–H H–C–C–O–H | | | | | | | H H H H H H H A B C D (2) 1.2 A renewable source of energy that can be produced by the fermentation of the sugar in sugarcane or corn is … A ethane. B ethanol. C methanol. D methane. (2) 1.3 Which ONE of the following polymers is the product of a condensation polymerisation reaction? A Polypropylene B Polyvinyl chloride C Polytetrafluoroethene D Polyactic acid (2) 1.4 Which ONE of the following is a balanced equation for the combustion of octane? A 2C8H18 + 25O2  16CO2 + 18H2O B C8H18 + 16O2  8CO2 + 9H2O C C8H18 + 32O2  8CO2 + 18H2O D 2C8H18 + 8O2  16CO2 + 9H2O (2) 1.5 Water undergoes auto-ionisation. During this process … A a proton is transferred from one water molecule to another. B water molecules act as proton donors only. C water molecules act as proton acceptors only. D the pH of water will decrease. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 4 PHYSICAL SCIENCES P2 (SEPTEMBER 2014) 1.6 A small quantity of concentrated hydrochloric acid is gradually added to 1 dm3 of distilled water at 25 °C. After testing the resultant solution, it is found that the value of Kw, [H3O+] and [OH-] in mol·dm-3 are: A Kw = 10-14 [H3O+] < 10-7 [OH-] > 10-7 B Kw < 10-14 [H3O+] < 10-7 [OH-] < 10-7 C Kw = 10-14 [H3O+] > 10-7 [OH-] < 10-7 D Kw = 10-14 [H3O+] = 10-7 [OH-] = 10-7 (2) 1.7 During the extraction of aluminium from pure aluminium oxide (alumina), a substance known as cryolite (Na3AℓF6) is added. The cryolite … A reduces the fluoride emissions during electrolysis. B lowers the melting point of the alumina. C prevents oxidation at the carbon electrodes. D prevents rusting of the electrolytic cell. (2) 1.8 N2O4(g) is placed in a sealed container. After a while the following reaction takes place in the container at constant temperature: N2O4(g) 2NO2(g) Which ONE of the following graphs correctly illustrates the relationship between the nitrogen dioxide (NO2) concentration, and time? A B C D (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) PHYSICAL SCIENCES P2 5 1.9 Consider the following reaction taking place in an open vessel at a certain temperature: 2H2O2(aq)  2H2O(ℓ) + O2(g) ΔH < 0 The initial reaction rate of the above reaction may be DECREASED by … A cooling the system. B adding MnO2 as a catalyst. C adding O2 gas to the system. D increasing the pressure of the system. (2) 1.10 Eutrophication … A causes soil acidification. B can lead to agricultural pests becoming resistant to pesticides. C is caused by bacterial nitrogen fixation. D is a process whereby excess plant nutrients stimulate excessive growth of algae. (2) TOTAL SECTION A: 20 Copyright reserved Please turn over

Downloaded from hlayiso.com 6 PHYSICAL SCIENCES P2 (SEPTEMBER 2014) SECTION B INSTRUCTIONS AND INFORMATION 1. Leave one line open between two subsections, for example between QUESTION 2.1 and QUESTION 2.2. 2. Start each question on a NEW page. 3. The formulae and substitutions must be shown in ALL calculations. 4. Round off your numerical answers to a minimum of TWO decimal places. QUESTION 2 (Start on a new page.) A few organic compounds (A–E) are represented in the table below. A CH3─ CHBr─CHBr─CH3 B CH3CH2CH2OH C pentanal D 2-methylpentanoic acid E CH3 – CH = C – CH3 | CH3 Write down the: 2.1 IUPAC name for compound A (2) 2.2 GENERAL FORMULA of the homologous series to which compound B belongs (1) 2.3 STRUCTURAL FORMULA of the functional group for compound C (1) 2.4 STRUCTURAL FORMULA for compound D (2) 2.5 STRUCTURAL FORMULA of a positional isomer for compound E (2) [8] Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) PHYSICAL SCIENCES P2 7 QUESTION 3 (Start on a new page.) The letters A–D in the flow diagram below represent some organic reactions that involve ethene. 3.1 Name the type of reaction (ADDITION, SUBSTITUTION or ELIMINATION) represented by: 3.1.1 A (1) 3.1.2 B (1) 3.1.3 D (1) 3.2 Apart from the alkene, another reactant and a catalyst are needed in Reaction A. Write down the NAME of the: (1) 3.2.1 Other reactant 3.2.2 Catalyst which was added to the alkene (1) 3.3 Use STRUCTURAL FORMULAE to write down a balanced chemical equation for the reaction represented by C. (4) Copyright reserved Please turn over

Downloaded from hlayiso.com 8 PHYSICAL SCIENCES P2 (SEPTEMBER 2014) 3.4 The ethanol produced in reaction A is made to react with a carboxylic acid in the presence of an acid catalyst. The compound formed is a STRAIGHT CHAIN ESTER which is a functional isomer of pentanoic acid. Write down the: 3.4.1 IUPAC NAME of the carboxylic acid that reacted with the alcohol (2) 3.4.2 Name given to this type of reaction (1) 3.4.3 STRUCTURAL FORMULA of the ester formed (2) 3.5 The polymerisation of ethene to produce polythene is represented by the equation below: nCH2 = CH2  – [CH2-CH2] n – 3.5.1 Define the term macromolecule. (1) 3.5.2 Classify this type of polymerisation. (1) 3.5.3 Name TWO industrial uses of polythene. (2) [18] Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) PHYSICAL SCIENCES P2 9 QUESTION 4 (Start on a new page.) The table below shows data collected for three organic compounds, represented by the letters A, B and C, during a practical investigation: Organic compound Relative molecular mass Boiling point (°C) A CH3CH2CH2CH3 58 -0,5 B CH3CH2CH2OH 60 97 C CH3COOH 60 118 4.1 Which variable was controlled during this investigation? (1) 4.2 Name the following in this investigation: 4.2.1 The dependent variable (1) 4.2.2 The independent variable (1) 4.3 Consider compound A: 4.3.1 Is compound A a saturated or an unsaturated hydrocarbon? Give a reason for your answer. (2) 4.3.2 The compound 2-methylpropane is an isomer of compound A. Predict whether the boiling point of 2-methylpropane will be HIGHER THAN, LOWER THAN or THE SAME as the boiling point of compound A. (1) 4.3.3 Explain your prediction in QUESTION 4.3.2. (3) 4.4 Refer to intermolecular forces and energy to explain why compound B will have a higher vapour pressure than compound C at 20 °C. (3) [12] Copyright reserved Please turn over

Downloaded from hlayiso.com 10 PHYSICAL SCIENCES P2 (SEPTEMBER 2014) QUESTION 5 (Start on a new page.) Graph B below represents the Maxwell-Boltzmann energy distribution curve for a reaction mixture at a temperature of 300°C. Area X represents the number of molecules in the mixture that have enough kinetic energy for the reaction to take place. 5.1 Give a term for the “minimum energy needed for a reaction to take place”, as indicated by Y. (1) 5.2 The temperature of the mixture is now increased to 500 °C. 5.2.1 Which ONE of graph A or C represents the distribution curve of the mixture at this higher temperature? Give a reason for the answer. (2) 5.2.2 Use the collision theory to explain how this increase in temperature will influence the rate of the reaction. (4) 5.3 A catalyst is added to the mixture. 5.3.1 Write down the definition of a positive catalyst. (2) 5.3.2 How will the above-mentioned action affect the size of area X (shaded area)? Write down only INCREASES, DECREASES or REMAINS THE SAME. (1) 5.3.3 Explain your answer to QUESTION 5.3.2. (2) [12] Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) PHYSICAL SCIENCES P2 11 QUESTION 6 (Start on a new page.) The catalytic oxidation of ammonia is represented by the equation below: 4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g) 2,0 mol of ammonia gas and 1,0 mol of oxygen gas are placed in a 2,0 dm3 container at 1 000 kPa and allowed to reach equilibrium at 1 000 °C. At this temperature and pressure the amount of water vapour present is 0,6 mol. 6.1 Calculate the value of the equilibrium constant at this temperature. (8) 6.2 Briefly explain the significance of the value obtained in QUESTION 6.1. (1) 6.3 What effect will the addition of a platinum catalyst have on the yield of NO(g) at the given temperature? Write down only INCREASE, DECREASE or REMAIN THE SAME. (1) 6.4 The pressure on the system is decreased by increasing the volume. Use Le Chatelier’s principle to explain how this change affects the yield of NO(g). (3) 6.5 It is found that at a temperature of 500 °C the value of the equilibrium constant is greater than the value calculated in QUESTION 6.1. What is the sign of ∆H for the reaction mentioned above? (1) 6.6 Explain your answer to QUESTION 6.5. (4) [18] Copyright reserved Please turn over

Downloaded from hlayiso.com 12 PHYSICAL SCIENCES P2 (SEPTEMBER 2014) QUESTION 7 (Start on a new page.) 7.1 Define a strong acid. (2) 7.2 A solution of an unknown, monoprotic acid has a concentration of 0,01 mol·dm-3 and a pH of 3. 7.2.1 Calculate the concentration of the hydrogen ions in this solution. (2) 7.2.2 How will the strength of this unknown acid compare to that of hydrochloric acid of the same concentration? Write down only STRONGER THAN, WEAKER THAN or EQUAL TO (1) 7.2.3 Give a reason for your answer in QUESTION 7.2.2. (2) 7.3 Ammonium chloride is an example of a salt that can undergo hydrolysis. 7.3.1 Define the underlined term. (2) 7.3.2 Write an equation to show the hydrolysis of ammonium chloride. (3) 7.3.3 Methyl orange is red in an acidic medium and yellow in an alkaline medium. What will the colour of methyl orange be in an ammonium chloride solution? (2) 7.4 A learner adds a sample of calcium carbonate to 50,0 cm3 of sulphuric acid. The sulphuric acid is in excess and has a concentration of 1,0 mol·dm-3. The balanced equation for the reaction that takes place is: CaCO3 + H2SO4  CaSO4 + CO2 + H2O ………… The reaction is allowed to proceed until all the CaCO3 is used up. The H2SO4 left over from REACTION 1 is now neutralised by 28,0 cm3 of a 0,5 mol·dm-3 sodium hydroxide solution. The balanced equation for this reaction is: H2SO4 + 2NaOH  Na2SO4 + 2H2O ………..… Calculate the mass of calcium carbonate in the sample used in REACTION 1. (10) [24] Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) PHYSICAL SCIENCES P2 13 QUESTION 8 (Start on a new page.) 8.1 Consider the following half reaction involving oxalic acid: solution. 2CO2 + 2H+ + 2e- H2C2O4 Eθ = -0,49 V A solution of potassium dichromate (K2Cr2O7 (aq)) is added to an oxalic acid (H2C2O4 (aq)) solution. 8.1.1 Explain why the reaction between the solution of oxalic acid and potassium dichromate will be spontaneous. Refer to the relative strengths of the oxidising and reducing agents in your answer. (3) 8.1.2 Use half-reactions to write down a balanced equation for the reaction between oxalic acid and potassium dichromate. Leave the answer in ionic form without spectator ions. (4) 8.2 A learner sets up a standard electrochemical cell using the following half- cells: Pt(s)/O2(g)/H+(aq), H2O2(aq) and Cu2+(aq)/Cu(s) Potassium chloride (KCℓ (aq)) solution is used in the salt bridge. 8.2.1 Which half cell (A or B) contains the cathode? (2) 8.2.2 Write down the oxidation half-reaction. (2) 8.2.3 Write down the cell notation for this cell. (3) 8.2.4 Calculate the potential difference of the cell (Eᶱcell). (4) 8.2.5 After several days, the reading on the voltmeter is 0,00 V. Explain why this reading is obtained. (4) [22] Copyright reserved Please turn over

Downloaded from hlayiso.com 14 PHYSICAL SCIENCES P2 (SEPTEMBER 2014) QUESTION 9 (Start on a new page.) The flow diagram below shows three industrial processes that result in the production of fertiliser Y. 9.1 Write down the name of the process A. (1) 9.2 Write down a balanced equation for the Haber process. (3) 9.3 Y is a fertiliser which can be used to lower the pH of alkaline soil. Write down the NAME of compound Y. (2) 9.4 Name the catalyst used in the production of sulphuric acid and explain why this process is called the “contact” process. (2) 9.5 Briefly discuss TWO disadvantages associated with the use of organic fertiliser like kraal-manure or compost. (4) 9.6 A bag of N:P:K fertiliser is labelled 3:1:5(26). 9.6.1 Calculate the percentage of potassium in the bag. (2) 9.6.2 Briefly discuss the role that potassium play in the development and growth of plants. (2) [16] TOTAL SECTION B: 130 GRAND TOTAL: 150 Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) PHYSICAL SCIENCES P2 15 NATIONAL SENIOR CERTIFICATE NASIONALE SENIOR SERTIFIKAAT 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 NAAM/NAME SIMBOOL/SYMBOL WAARDE/VALUE Standard pressure p 1,013 x 105 Pa Standaarddruk Molar gas volume at STP Vm 22,4 dm3∙mol-1 Molêre gasvolume teen STD Standard temperature Tθ 273 K Standaardtemperatuur Charge on electron -19 e -1,6 x 10 C Lading op elektron Avogadro’s constant NA 6,02 x 1023 mol-1 Avogadro se konstante TABLE 2: FORMULAE/TABEL 2: FORMULES m n m n or of c or of c pH= -log[H3O+] Kw = [H3O+][OH-] = 1x10-14 ca a na at /by 298K n or of A cb b nb n o Eθcell = Eθcathode – Eθanode / Eθsel = Eθkatode – Eθanode Eθcell = Eθreduction – Eθoxidation / Eθsel = Eθreduksie – Eθoksidasie Eθcell = Eθoxidising agent – Eθreducing agent / Eθsel = Eθoksideermiddel – Eθreduseermiddel Copyright reserved Please turn over

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(SEPTEMBER 2014) Downloaded from hlayiso.com PHYSICAL SCIENCES P2 16 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) KEY/ SLEUTEL Atoomgetal 1 Atomic number 2 2,1 H He 1 29 4 3 4 Elektronegatiwiteit Simbool 5 6 7 8 9 10 1,0 Li 1,5 Be Electronegativity 1,9 Cu Symbol 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 Benaderde relatiewe atoommassa 1,5 Aℓ 1,8 Si 2,1 P 2,5 S 3,0 Cℓ Ar 23 24 Approximate relative atomic mass 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 1,5Ti 1,6 V 1,6 Cr 1,5 Mn 1,8 Fe 1,8 Co 1,8Ni 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 1,4Zr 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 1,6Hf 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

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Downloaded from hlayiso.com 17 PHYSICAL SCIENCES P2 (SEPTEMBER 2014) TABLE 4A: STANDARD REDUCTION POTENTIALS TABEL 4A: STANDAARD REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E θ (V) F2(g) + 2e ⇌ 2F + 2,87  Co 3+ +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 3+ Cr2O 7 + 14H+ + 6e ⇌ 2Cr + 7H2O + 1,33 +  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 Increasing reducing ability/Toenemende reduserende vermoë Increasing oxidising ability/Toenemende oksiderende vermoë  Hg 2+ + 2e ⇌ Hg(ℓ) + 0,85 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 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  Sn 2+ + 2e ⇌ Sn  0,14 Ni2+ + 2e ⇌ Ni  0,27 Co2+ + 2e ⇌ Co  0,28 Cd2+ + 2e ⇌ Cd  0,40  Cr 3+ +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  Mg 2+ + 2e ⇌ Mg  2,36 Na+ + e ⇌ Na  2,71 Ca2+ + 2e ⇌ Ca  2,87 Sr2+ + 2e ⇌ Sr  2,89  Ba 2+ + 2e ⇌ Ba  2,90 Cs+ + e- ⇌ Cs - 2,92 K+ + e ⇌ K  2,93 Li+ + e ⇌ Li  3,05

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Downloaded from hlayiso.com (SEPTEMBER 2014) PHYSICAL SCIENCES P2 18 TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E θ (V) Li + e  3,05 + ⇌ Li K + e  2,93 + ⇌ K Cs + e  2,92 + ⇌ Cs   2,90 2+ Ba + 2e ⇌ 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   0,91 2+ Cr + 2e ⇌ Cr Increasing oxidising ability/Toenemende oksiderende vermoë Increasing reducing ability/Toenemende reduserende vermoë 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  0,41 3+ 2+ ⇌ Cr Cd + 2e  0,40 2+ ⇌ Cd   0,28 2+ Co + 2e ⇌ 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 4+ 2+ ⇌ 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 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 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 Co + e 3+ 2+ ⇌ Co + 1,81 F2(g) + 2e ⇌ 2F + 2,87 Copyright reserved Please turn over

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