2017 Chemistry P2 NC FS_hlayiso.com_.pdf

Downloaded from hlayiso.com PREPARATORY EXAMINATION GRADE 12 PHYSICAL SCIENCES P2 (CHEMISTRY) SEPTEMBER 2017 MARKS: 150 TIME: 3 HOURS This question paper consists of 18 pages, 1 graph paper and 4 data sheets. Copyright reserved Acknowledgement to Northern Cape Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 2 September 2017 INSTRUCTIONS AND INFORMATION 1. Write your name 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. 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. Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 3 September 2017 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–D) next to the question number (1.1–1.10) in the ANSWER SHEET, for example 1.11 E. 1.1 Which ONE of the following pairs of compounds belong to the same homologous series? A C2H6 and C4H12 B C3H6 and C5H8 C CH4O and C2H4O2 D C2H2 and C3H4 (2) 1.2 Which ONE of the following compounds is an isomer of CH3CH2COOH? H3C C O CH3 O A B O H C CH3 O C CH3 CH2 CH2 OH D H3C C CH3 (2) 1.3 The hydrogenation of sunflower oil results in the production of margarine. During this process the ... A number of double bonds increases. B carbon chain increases. C number of double bonds decreases. D compound becomes less saturated. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 4 September 2017 1.4 Consider the following reversible reaction: CO(g) + H2O(g) ⇌ CO2(g) + H2(g) ∆H › 0 The temperature is now lowered. Which ONE of the following statements is correct? A The rate of the forward reaction is increased. B The rate of both the forward and the reverse reactions decreased. C The rate of the reverse reaction is decreased. D The rate of both the forward and the reverse reactions increased. (2) 1.5 Hydrogen gas is produced in the reaction between hydrochloric acid and magnesium. Which ONE of the following graphs of volume versus time best represents the formation of hydrogen gas until the reactants are used up? A B volume (cm3) volume (cm3) time (s) time (s) C D volume (cm3) volume (cm3) time (s) time (s) (2) 1.6 The addition of a catalyst to a reversible reaction at equilibrium increases the … A equilibrium constant of the forward reaction. B product produced at equilibrium. C the rate of both the forward and reverse reactions. D rate of only the forward reaction. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 5 September 2017 1.7 Consider the reaction CaO(s) + SO2(g) ⇌ CaSO3(s) at equilibrium in a closed container. If the equilibrium concentration of SO2(g) at 25°C is x mol.dm-3, the value of the equilibrium constant at this temperature is ... A x B x2 1 C x2 1 D x (2) 1.8 A 0,5 mol∙dm-3 solution of each of the following acids is prepared. Which acid has the greatest electrical conductivity? A H2SO4 B HCl C CH3COOH D HNO3 (2) 1.9 Which ONE of the following solutions will react spontaneously with copper? A NaCl (aq) B AgNO3 (aq) C ZnSO4 (aq) D Pb(NO3)2 (aq) (2) 1.10 Which ONE of the following nutrients is responsible for the growth of green leaves in plants? A Phosphorous B Nitrogen C Potassium D Magnesium (2) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 6 September 2017 QUESTION 2 (Start on a new page.) Study the organic compounds represented by the letters A to F in the table below and answer the following questions. H H O H A propanal B H C C C C H H H H H H H H H C H C O C H D H C C C C H O H H H H H E CH3CH2CH2COOH F CH2 CH2 2.1 Name the homologous series to which each of the following compounds belong: 2.1.1 A (1) 2.1.2 B (1) 2.2 Write down the IUPAC name of the alcohol needed for the preparation of compound C. (2) 2.3 Write down the letter for the compound that represents a carboxylic acid. (1) 2.4 Polymers are organic compounds with a wide range of applications in everyday life. 2.4.1 Define an addition polymer. (2) 2.4.2 Write down the letter that represents a monomer of an addition polymer. (1) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 7 September 2017 2.5 Give the STRUCTURAL FORMULA for the functional group of compoun A. (1) 2.6 Give the general formula for the homologous series to which compound F belong. (1) 2.7 Is compound D a saturated or unsaturated hydrocarbon? Give a reason for your answer. (2) 2.8 Using molecular formulae write down a balanced chemical equation for the combustion of compound D. (3) [15] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 8 September 2017 QUESTION 3 (Start on a new page.) A group of learners were investigating the intermolecular forces and physical properties of various organic compounds. As part of their research they determined the boiling point of eight different compounds represented by letters A to H in the table below: Compound Molecular Boiling point mass (M) (oC) (g∙mol-1) A methyl 58 -12 propane B butane 58 -0,5 C pentane 72 36 D propan-1-ol 60 97 E butan-1-ol 74 117 F pentan-1-ol 88 138 G ethanoic acid 60 118 H ethyl 58 77,1 ethanoate 3.1 Give the STRUCTURAL FORMULA for compound H. (2) 3.2 Explain why compounds D and G have different boiling points despite the fact that they have the same molecular mass. In your explanation refer to the MOLECULAR STRUCTURE, the INTERMOLECULAR FORCES and the ENERGY needed. (3) 3.3 Compounds A to C have different boiling points even though they belong to the same homologous series. Explain the reason for the difference in their boiling points. (2) 3.4 How will the vapour pressure of compound G compare to that of compound H? Write only HIGHER THAN, LOWER THAN or EQUAL TO. (1) 3.5 Compounds A and B are structural isomers 3.5.1 Define the term structural isomer. (2) 3.5.2 Name the type of structural isomerism shown by compounds A and B. (1) [11] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 9 September 2017 QUESTION 4 (Start on a new page.) The letters B to H in the flow diagram represent different reactions. Butyl propanoate G alkane alkene H D F C E B 2-chlorobutane alcohol 4.1 Which type of reaction is represented by EACH of the following? Write only ADDITION, SUBSTITUTION or ELIMINATION. 4.1.1 Reaction D (1) 4.1.2 Reaction E (1) 4.2 2-chlorobutane is converted into an alkene through reaction F. Write down the structural formula of the MAJOR PRODUCT formed in this reaction. (2) 4.3 Using structural formulae write down a balanced chemical equation for reaction C. (4) 4.4 Write down TWO reaction conditions for the reaction B. (2) 4.5 Reaction G is an addition reaction. Write down the: 4.5.1 IUPAC name of the alkane formed in this reaction (1) 4.5.2 Type of the addition reaction (1) 4.6 Reaction H represents the reaction between an alcohol and a carboxylic acid in the presence of a catalyst. Write down the: 4.6.1 IUPAC name of the carboxylic acid used in this reaction (1) 4.6.2 NAME of the catalyst (1) 4.6.3 The name of the process that takes place in QUESTION 4.6. (1) [15] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 10 September 2017 QUESTION 5 (Start on a new page.) A group of learners were investigating the factors affecting the reaction rate. In one of their reactions sodium thiosulphate (Na2S2O3) and hydrochloric acid (HCℓ) are reacted according to the balanced equation given below: Na2S2O3(aq) + 2HCℓ (aq) → 2NaCℓ (aq) + S(s) + H2O(ℓ) + SO2(g) During the reaction one of the products formed causes the solution to turn cloudy. Due to this, the mark X drawn on paper, on which the reaction mixture is placed, were not visible after the reaction is completed. Refer the sketch below. Look from above flask Na2S2O3(aq) + HCℓ(aq) white paper view from above the beaker X X X X X grows fainter with time Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 11 September 2017 In the investigation the learners took sodium thiosulphate of different concentration and reacted it with hydrochloric acid of constant concentration. They recorded the time taken for the mark X on the paper to disappear. Their result is tabulated below. Trial 1 2 3 4 Concentration 0,15 0,09 0,06 0,03 Na2S2O3(mol.dm-3) Time taken for the X to disappear in 43 66 100 240 (s) 5.1 Define the term reaction rate. (2) 5.2 For the experiment described above, name the: 5.2.1 Independent variable (1) 5.2.2 ONE control variable (1) 5.3 Write down the NAME or FORMULA of the substance responsible for the cloudiness. (1) 5.4 Consider the table of results and write down which trial (1, 2, 3 or 4) occurred at the highest reaction rate? (1) 5.5 Draw a graph of concentration of sodium thiosulphate against time for the mark X to disappear in the ATTACHED GRAPH SHEET. (4) 5.6 Use the graph to make a conclusion for the above investigation. (2) 5.7 Name TWO other ways in which the rate of this reaction can be increased. (2) [14] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 12 September 2017 QUESTION 6 (Start on a new page.) One of the steps in the preparation of sulphuric acid in the industry is represented by the following reversible reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g) The graph below shows the energy change during this reaction. Potential Energy/kJ∙mol-1 68 25 0 reaction coordinate -86 6.1 Write down the type of reaction represented by above graph. Choose from EXOTHERMIC or ENDOTHERMIC. Explain your answer. (2) 6.2 According to collision theory, give TWO conditions necessary for the reaction to take place. (2) Vanadium pentoxide is added as a catalyst in the above reaction. 6.3 Explain how the presence of a vanadium pentoxide as a catalyst affect the rate of above reaction. (2) 6.4 Calculate the enthalpy change of this reaction. (3) At 68 kJ∙mol-1 an activated complex is formed. 6.5 Define the term activated complex. (2) 6.6 Calculate the activation energy for the reverse reaction. (2) [13] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 13 September 2017 QUESTION 7 (Start on a new page.) Consider the reversible reaction represented by the following balanced equation. 2NO(g) + O2(g) ⇌ 2NO2(g) During this reaction 4 mole of nitrogen monoxide gas, 2,5 mole of oxygen and x mole of nitrogen dioxide gas is placed in an 500 cm3 container at a temperature of 450 K. At equilibrium there is 3 mole of nitrogen oxide present in the container. The equilibrium constant (Kc) at this temperature is 0,25. 7.1 Calculate the initial mole of nitrogen dioxide placed in the container. (7) 7.2 Is the given equilibrium system an example of a heterogeneous or homogeneous equilibrium? Explain your answer. (2) 7.3 State Le Chatelier's principle. (2) Now the pressure is increased. 7.4 Use Le Chatelier's principle to explain how this change affects the concentration of NO2 at the new equilibrium. (2) [13] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 14 September 2017 QUESTION 8 (Start on a new page.) A learner takes 20 cm3 of sodium hydrogen carbonate (NaHCO3) solution of unknown concentration and titrate it against a standard solution of sulphuric acid with a pH of 1. 8.1 Define a standard solution. (2) 8.2 Write down the formula of the conjugate base for sulphuric acid. (1) The balanced chemical equation for the titration is given below: 2NaHCO3 + H2SO4 → Na2SO4 + 2CO2 + 2H2O 8.3 Calculate the concentration of the sodium hydrogen carbonate solution if it neutralizes 12 cm3 of the sulphuric acid solution. (7) 8.4 What mass of the sodium hydrogen carbonate is needed to prepare a 250 cm3 solution that the learner used in the titration? (3) 8.5 Which indicator would be best to use during this titration? Explain your choice. (2) [15] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 15 September 2017 QUESTION 9 (Start on a new page.) 9.1 The cell notation of a standard galvanic cell that contains an unkown metal electrode X, is as follows: Zn(s) | Zn2+(1 mol∙dm-3) || X2+(1 mol∙dm-3) | X(s) V X Zn(s) salt bridge X2+(aq) Zn2+(aq) 9.1.1 Name the component of the cell that is represented by the double vertical lines (||) in the cell notation. (1) 9.1.2 Name TWO standard conditions that is applicable to the Zn2+|Zn- half cell. (2) 9.1.3 Identify the reducing agent in the above mentioned cell. (1) 9.1.4 The initial reading on the volt meter connected to the electrodes of the above given cell is 0,49 V. Identify metal X by calculating the standard reduction potential of the unkown metal X. (5) 9.1.5 Write a balanced chemical equation for the net reaction that takes place in this cell. Leave out the spectator ions. (3) 9.1.6 How will the initial voltmeter reading be influenced if the two metal plates are replaced by metal plates that have a larger surface? Write only INCREASES, DECREASES or STAYS THE SAME (1) 9.1.7 Write down the value of the reading on the volt meter when the cell reaction reaches equilibrium. (1) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 16 September 2017 9.2 The simplified diagram below represents an electrochemical cell used for the purification of copper. DC source Electrode A Electrode B (impure copper) Electrolyte 9.2.1 Write down the energy conversion that takes place in the above cell in QUESTION 9.2. (1) 9.2.2 Write down the NAME or FORMULA of the electrolyte that can be used in the above cell. (1) 9.2.3 Write down the half-reaction which takes place at electrode A. (2) [18] Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 17 September 2017 QUESTION 10 (Start on a new page.) Ammonia is the main reactant in the production of various fertilizers. The following flow diagram illustrates the process of the manufacturing of some fertilizers. N2(g) X PROCESS R PROCESS Q Haber process HNO3 Ammonia H2SO4 Y Z 10.1 Write down the NAME of the industrial process used to manufacture nitrogen gas. (1) 10.2 Write a balanced chemical equation for the preparation of ammonia. (3) 10.3 Identify the following in the flow diagram: 10.3.1 PROCESS R (1) 10.3.2 Compound Z (1) 10.4 Write down the balanced equation for the oxidation of sulphur dioxide in PROCESS Q. (3) 10.5 Write down the FORMULA of compound Y. (1) Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 18 September 2017 10.6 A farmer find a old bag of fertilizer weighing 50 kg. The label of the bag is partly damaged. One number in the N:P:K ratio was missing (see diagram). 5:2: -- (30) 50 kg The farmer analysed the content of the fertilizer and found that the nitrogen content in the bag is 15%. Determine the number that is missing on the label of the fertiliser bag regarding the N:P:K ratio. Assume that no content is lost due to aging. (4) 10.7 Eutrofication is the result of excessive use of inorganic fertilizers. Explain what is meant by eutrofication. (2) [16] TOTAL: 150 Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 19 September 2017 QUESTION 5.5 SURNAME AND NAME CLASS Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 1 September 2017 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 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 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+] c b v b 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  Ereducingagent / E sel  Eoksideermiddel  Ereduseermiddel θ θ θ θ Copyright reserved Please turn over

Physical Sciences P2/Grade 12 Downloaded from hlayiso.com 2 September 2017 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 2017 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 + 2e 2+ Pt ⇌ Pt + 1,20   Br2(ℓ) + 2e ⇌ 2Br + 1,07  +  NO 3 + 4H + 3e ⇌ NO(g) + 2H2O + 0,96 Increasing reducing ability/Toenemende reduserende vermoë 2+  Hg + 2e ⇌ Hg(ℓ) + 0,85 Ag + e + ⇌ Ag + 0,80 Increasing oxidising ability/Toenemende oksiderende vermoë  +  NO 3 + 2H + e ⇌ NO2(g) + H2O + 0,80 + e 3+ 2+ Fe ⇌ 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 + 2e 2+ Cu ⇌ Cu + 0,34 2 SO 4 + 4H + 2e ⇌ + SO2(g) + 2H2O + 0,17 + e 2+ + Cu ⇌ Cu + 0,16 4+  2+ Sn + 2e ⇌ Sn + 0,15 S + 2H + 2e + ⇌ H2S(g) + 0,14 +  2H + 2e ⇌ H2(g) 0,00 + 3e  0,06 3+ Fe ⇌ Fe + 2e  0,13 2+ Pb ⇌ Pb + 2e  0,14 2+ Sn ⇌ Sn   0,27 2+ Ni + 2e ⇌ Ni + 2e  0,28 2+ Co ⇌ Co   0,40 2+ Cd + 2e ⇌ Cd + e 2+  0,41 3+ Cr ⇌ Cr   0,44 2+ Fe + 2e ⇌ Fe + 3e  0,74 3+ Cr ⇌ Cr + 2e  0,76 2+ Zn ⇌ Zn   2H2O + 2e ⇌ H2(g) + 2OH  0,83 + 2e  0,91 2+ Cr ⇌ Cr   1,18 2+ Mn + 2e ⇌ Mn + 3e  1,66 3+ Aℓ ⇌ Aℓ   2,36 2+ Mg + 2e ⇌ Mg Na + e  2,71 + ⇌ Na   2,87 2+ Ca + 2e ⇌ Ca Sr + 2e  2,89 2+ ⇌ Sr   2,90 2+ Ba + 2e ⇌ Ba + - Cs + e ⇌ Cs - 2,92 K + e  2,93 + ⇌ K Li + e  3,05 + ⇌ Li Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences P2/Grade 12 4 September 2017 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   2,92 + Cs + e ⇌ Cs + 2e  2,90 2+ Ba ⇌ Ba   2,89 2+ Sr + 2e ⇌ Sr + 2e  2,87 2+ Ca ⇌ Ca   2,71 + Na + e ⇌ Na + 2e  2,36 2+ Mg ⇌ Mg Increasing oxidising ability/Toenemende oksiderende vermoë Increasing reducing ability/Toenemende reduserende vermoë   1,66 3+ Aℓ + 3e ⇌ Aℓ + 2e  1,18 2+ Mn ⇌ Mn   0,91 2+ Cr + 2e ⇌ Cr 2H2O + 2e ⇌ H2(g) + 2OH  0,83 + 2e  0,76 2+ Zn ⇌ Zn   0,74 3+ Cr + 3e ⇌ Cr + 2e  0,44 2+ Fe ⇌ Fe  2+  0,41 3+ Cr +e ⇌ Cr + 2e  0,40 2+ Cd ⇌ Cd   0,28 2+ Co + 2e ⇌ Co + 2e  0,27 2+ Ni ⇌ Ni   0,14 2+ Sn + 2e ⇌ Sn + 2e  0,13 2+ Pb ⇌ Pb   0,06 3+ Fe + 3e ⇌ Fe 2H + 2e + ⇌ H2(g) 0,00 S + 2H + 2e + ⇌ H2S(g) + 0,14 4+  2+ Sn + 2e ⇌ Sn + 0,15 + e 2+ + Cu ⇌ Cu + 0,16 2 SO 4 + 4H + 2e ⇌ + SO2(g) + 2H2O + 0,17 + 2e 2+ Cu ⇌ 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 + e 3+ 2+ Fe ⇌ Fe + 0,77  + 2H + e + NO 3 ⇌ NO2(g) + H2O + 0,80 Ag + e + ⇌ Ag + 0,80 + 2e 2+ Hg ⇌ Hg(ℓ) + 0,85  +  NO 3 + 4H + 3e ⇌ NO(g) + 2H2O + 0,96   Br2(ℓ) + 2e ⇌ 2Br + 1,07 2+  Pt +2e ⇌ 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 3+  2+ Co +e ⇌ Co + 1,81 F2(g) + 2e ⇌ 2F + 2,87 Copyright reserved