Physical Sciences Grade 12 P2 Eastern Cape Mock 2022 QP

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 SEPTEMBER 2022 PHYSICAL SCIENCES P2 (CHEMISTRY) MARKS: 150 TIME: 3 hours This question paper consists of 21 pages, including 4 data sheets.

Downloaded from hlayiso.com 2 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) INSTRUCTIONS AND INFORMATION 1. Write your full NAME and SURNAME in the appropriate spaces 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 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. 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, et cetera 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 (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 3 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A–D) next to the question numbers (1.1 to 1.10) in the ANSWER BOOK, for example 1.11 D. 1.1 The name of the functional group of propanoic acid is ... A formyl. B carboxyl. C carbonyl. D hydroxyl. (2) 1.2 Which ONE of the following is the CORRECT name for the addition reaction of water to an alkene? A hydration B hydrolysis C dehydration D hydrohalogenation (2) 1.3 Consider the compound shown below: H CH3 CH3 H H H C C C C C H H H H Br H The CORRECT IUPAC name of the above compound is: A 4-bromo-2,3-dimethylpentane B 2-bromo-3,4-dimethylpentane C 2,3-dimethyl-4-bromopentane D 3,4-dimethyl-2-bromopentane (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 4 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) 1.4 Which ONE of the following organic molecules will react rapidly with bromine water? A CH3CH2OH B CH3CH3 C CH2CH2 D CH3CH2CH3 (2) 1.5 Consider the potential energy profile below for the following hypothetical reaction: P ⇌ Q Potential energy (kJ·mol-1) a Q b P c Reaction progress Which ONE of the following combinations correctly indicates both the activation energy and the heat of reaction (ΔH) for the REVERSE REACTION? Activation energy (kJ·mol-1) Heat of reaction (ΔH) A a–b b–c B b–a a–c C a–b c–b D b–c a–b (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 5 1.6 H2S (g) decomposes according to the following balanced equation: H2S (g) ⇌ H2 (g) + S (s) In each of four separate experiments, A to D, H2S of initial concentration ci is placed in identical empty flasks which are then sealed and heated. The graphs below display the results of the experiments A to D. Which experiment has the largest Kc value? A B Concentration Concentration ci ci 0 time 0 time C D Concentration Concentration ci ci 0 time 0 time (2) 1.7 The reaction below represents the general equation for the reaction of an acid-base indicator. HIn (aq) + H2O (ℓ) ⇌ H3O+ (aq) + In – (aq) yellow blue In which ONE of the following salt solutions will this indicator turn yellow? A KCℓ(aq) B NH4Cℓ(aq) C NaHCO3(aq) D CH3COONa(aq) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 6 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) 1.8 The function of a salt bridge in a galvanic cell is to … A allow for the movements of protons. B allow for the movements of electrons. C provide a site for reduction to occur. D ensure electrical neutrality of solutions. (2) 1.9 Which ONE the substances can act as an ampholyte in some reactions? A CH3COO– B HSO4 – C H3O+ D NH4+ (2) 1.10 The electrolytic cell below is used during the electroplating of an iron ring with copper. Power Cu Iron ring Which ONE of the following combinations is CORRECT about the ions in the electrolyte when the cell is operating? Concentration Positive ions A Remain constant Cu2+ B Remain constant Fe2+ C Increases Fe3+ D Increases Cu2+ (2) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 7 QUESTION 2 (Start on a new page.) The letters A to D in the table below represent four organic compounds that belong to different homologous series. A B CH3 2-methylpropanal H H CH2 H O H C C C C C O H H H H CH3 C D CH3C ≡ CCH2CH3 Pentane 2.1 Define the term homologous series. (2) 2.2 Write down the: 2.2.1 Letter that represents a saturated hydrocarbon (1) 2.2.2 General formula of the homologous series to which compound C belongs (1) 2.2.3 Structural formula of compound A (2) 2.3 Write down the IUPAC name of compound B. (3) 2.4 Compound D has three structural isomers. Write down the: 2.4.1 Structural formula of the isomer with the shortest chain (3) 2.4.2 Balanced equation for the combustion reaction of compound D in EXCESS oxygen using molecular formulae (3) [15] Copyright reserved Please turn over

Downloaded from hlayiso.com 8 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) QUESTION 3 (Start on a new page.) 3.1 The graphs below show the boiling points of straight chain primary alcohols and straight chain ketones with different number of carbon atoms. 160 Alcohols 140 Boiling point (oC) Ketones 120 100 80 60 40 5 7 Number of carbon atoms 3.1.1 Define the term boiling point. (2) 3.1.2 Explain why the boiling points of alcohols increase as the number of carbon atoms increase by referring to TYPE and STRENGTH of intermolecular forces only. (2) 3.1.3 Explain why the curve of the alcohols is higher than that of the ketones. Refer to the TYPE and STRENGTH of intermolecular forces involved. (3) The vapour pressure of the alcohol is compared to that of a ketone at the same temperature. 3.1.4 Why must the alcohol and ketone which are used for the comparison have the same number of carbon atoms? (1) 3.1.5 Which ONE will have a higher vapour pressure: ALCOHOL or KETONE? Give a reason for the answer by referring to the data in the graph. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 9 3.2 The boiling points of propanoic acid and propan-1-ol are compared. 3.2.1 Which compound has the higher boiling point? (1) 3.2.2 Explain the answer to QUESTION 3.2.1 by referring to TYPE, STRENGTH of intermolecular forces and ENERGY. (3) [14] Copyright reserved Please turn over

Downloaded from hlayiso.com 10 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) QUESTION 4 (Start on a new page.) 4.1 Compound P can be used to prepare organic compounds R and Q as shown in the flow diagram below. Alcohol P HCℓ Haloalkane Q II I Concentrated H2SO4 O Compound R: CH3CH2CH2OCCH3 In reaction I, alcohol P reacts with another organic compound in the presence of concentrated sulphuric acid. 4.1.1 Name the type of reaction represented by I. (1) 4.1.2 Besides the presence of a catalyst write down another reaction condition for reaction I. (1) Write down the: 4.1.3 Structural formula of alcohol P (2) 4.1.4 IUPAC name of compound R (2) 4.1.5 IUPAC name of a straight chain FUNCTIONAL isomer of compound R (2) For reaction II write down the: 4.1.6 Type of reaction taking place (1) 4.1.7 Formula of the inorganic product (1) 4.1.8 Condensed structural formula of compound Q (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 11 4.2 A primary alcohol that contains 3 carbon atoms is converted to a secondary alcohol in a TWO step process as shown in the flow diagram below: STEP 1 STEP 2 Primary alcohol Compound Q Secondary alcohol P P is an inorganic reagent while compound Q is an organic compound. Write down the: 4.2.1 Formula of reagent P (2) 4.2.2 One reaction condition for the reaction in STEP 2 (1) 4.2.3 A balanced equation for the reaction in STEP 2 by using structural formulae for the organic compounds. (5) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com 12 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) QUESTION 5 (Start on a new page.) The reaction between sodium thiosulphate (Na2S2O3) and EXCESS hydrochloric acid (HCℓ) is used to investigate the effect of concentration and temperature on the rate of reaction. The balanced equation for this reaction is: Na2S2O3 (aq) + 2 HCℓ → 2 NaCℓ (aq) + S (s) + SO2 (g) + H2O (ℓ) An Erlenmeyer flask is placed on a white paper marked with a light cross on it. The time taken for the visibility of the cross (X) to disappear is measured. See the diagram below. Na2S2O3 solution with HCℓ White paper NOTE: The same volume of Na2S2O3 solution was used for all three reactions. The table below shows the reaction conditions. Exp Concentration Concentration Temperature Volume of of Na2S2O3 of HCℓ (°C) HCℓ (mol·dm-3) (cm3) 1 0,05 2 25 25 2 0,05 1 25 25 3 0,05 2 40 25 5.1 Define the term reaction rate. (2) 5.2 Write down the name of the independent variable for the comparison of experiment 1 and 2. (1) 5.3 How will the amount of sulphur (S) formed in experiment 1 compare to the amount of sulphur (S) produced in experiment 2 at the completion of the reaction? Choose from HIGHER THAN, LOWER THAN or EQUAL TO. Give a reason for the answer. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 13 5.4 Experiments 1 and 3 are now compared. The Maxwell-Boltzmann energy distribution curves for Experiments 1 and 3 are shown below. Number of particles T1 T2 Kinetic energy Ea 5.4.1 Which experiment 1 or 3 is represented by curve T2? (1) 5.4.2 Explain the answer to QUESTION 5.4.1 by referring to the collision theory. (3) 5.4.3 Sketch the curve of T2 ONLY in the answer book and indicate the effect that a catalyst would have on Ea. Indicate the new activation energy as X on the graph. (2) 5.5 0,7118 g of Na2S2O3 reacted completely with HCℓ in experiment 1 in 34 s. Calculate the rate at which HCℓ reacted in experiment 1 in mol·s-1. (5) The volume of HCℓ used in experiment 1 is now doubled. All other reaction conditions remain the same. 5.6 How would the reaction rate be affected by the change in volume? Choose from INCREASES, DECREASES or REMAIN THE SAME. (1) [17] Copyright reserved Please turn over

Downloaded from hlayiso.com 14 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) QUESTION 6 (Start on a new page.) 6.1 The following reversible reaction can be used to demonstrate how certain factors influence chemical equilibrium: CoCℓ42– (aq) + 6 H2O (ℓ) ⇌ Co(H2O)62+ (aq) + 4 Cℓ – (aq) Blue Pink 6.1.1 Define the term reversible reaction. (2) Initially, the solution is BLUE. Write down either TURNS MORE BLUE or TURNS MORE PINK to describe what happens to the reaction mixture if some: 6.1.2 CoCℓ42- is added (1) 6.1.3 Concentrated HCℓ is added (1) The test tube containing the reaction mixture is placed in a hot water bath. It is observed that the solution becomes more blue. 6.1.4 Is the forward reaction EXOTHERMIC or ENDOTHERMIC? (1) 6.1.5 Explain the answer to QUESTION 6.1.4 by referring to Le Chatelier’s principle. (2) 6.2 3,01 x 10 23 molecules of N2O4 are sealed into a 4 dm3 container and then heated to 400 K. The following balanced equation represents the reaction that reaches equilibrium in the container at 400 K. N2O4 (g) ⇌ 2 NO2 (g) At equilibrium, it is found that 0,4 mol of N2O4 have decomposed to NO2 Calculate the equilibrium constant (Kc) at 400 K. (8) [15] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 15 QUESTION 7 (Start on a new page.) 7.1 The equations below show the reactions occurring in hydrochloric acid (HCℓ) and ethanoic acid (CH3COOH) solutions. Both acids have a concentration of 1 mol·dm-3, and are kept at a temperature of 25° C. I: HCℓ (aq) + H2O (ℓ) ⇌ Cℓ – (aq) + H3O+ (aq) Ka = 1,3 × 106 II: CH3COOH (aq) + H2O (ℓ) ⇌ CH3COO– (aq) + H3O+ (aq) Ka = 1,8 × 10-5 7.1.1 Define an acid according to the Lowry-Brønsted theory. (2) 7.1.2 Write down ONE conjugate acid pair-base pair in reaction I. (2) 7.1.3 Which solution, I or II, will have the lower pH value? Explain the answer. (3) 7.2 10 cm3 of a 1 mol·dm-3 sodium hydroxide (NaOH) solution is diluted with water until its pH is 13. 7.2.1 Calculate the number of moles of NaOH in the 10 cm 3 of the initial solution. (3) 7.2.2 Calculate the volume of the diluted solution in dm3. (5) All of the diluted sodium hydroxide solution is poured into a burette. During a titration, 15 cm3 of oxalic acid of concentration 0,09 mol·dm-3 is exactly neutralised by a certain volume of the diluted sodium hydroxide solution. The balanced equation for the reaction is: 2 NaOH (aq) + H2C2O4 (aq) → Na2C2O4 (aq) + 2 H2O (ℓ) 7.2.3 Calculate the volume of the diluted sodium hydroxide that is left in the burette after the titration. (5) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com 16 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) QUESTION 8 (Start on a new page.) A galvanic cell is set up under standard conditions using half-cells A and B shown below. Half-cell A: Cu(s)/Cu2+(aq) Half-cell B: H2O(ℓ) /O2(g)/ H+(aq) 8.1 Define oxidation in terms of electron transfer. (2) 8.2 Write down the: 8.2.1 Initial concentration of the H+(aq) solution in half-cell B (1) 8.2.2 Name of the metal used as the electrode in half-cell B (1) 8.2.3 Formula of the reducing agent (1) 8.2.4 Reduction half reaction (2) 8.2.5 Balanced ionic equation for the overall cell reaction (3) 8.3 The graph below shows the EMF of this cell against time. x EMF (V) 0 Time (s) t1 8.3.1 Calculate the value of x on the graph. (4) 8.3.2 Explain the decrease in the EMF of the cell as time proceeds. (2) 8.3.3 What has happened to the reaction in the cell at time t1? (1) [17] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 17 QUESTION 9 (Start on a new page.) 9.1 The diagram represents the apparatus used in the electrolysis of a concentrated NaCℓ solution. A and B are two carbon electrodes. A B NaCℓ (aq) 9.1.1 Define an electrolytic cell. (2) 9.1.2 Write down the half reaction that occurs at electrode B. (2) Gas bubbles are observed at the cathode of the cell. 9.1.3 Write down the NAME or FORMULA of the gas formed at the cathode. (1) 9.1.4 Refer to the relative strengths of the oxidising agents to explain why the gas in QUESTION 9.1.3 and not Na, is formed at the cathode. (2) 9.2 An electrolytic cell is using an impure copper electrode consisting of 95% Cu and a pure copper electrode. Copper (II) chloride (CuCℓ2) solution is used as the electrolyte. 9.2.1 Is the pure copper the ANODE or CATHODE? (1) 9.2.2 When all the copper in the impure copper electrode has been deposited on the copper electrode, it is found that 6 mol of electrons were transferred. Calculate the initial mass of the IMPURE copper electrode. (4) [12] TOTAL: 150 Copyright reserved Please turn over

Downloaded from hlayiso.com 18 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) 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 × 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 e -1,6 × 10-19 C Lading op elektron Avogadro’s constant NA 6,02 × 1023 mol-1 Avogadro se konstante TABLE 2: FORMULAE/TABEL 2: FORMULES m n m n = M or/of c = V or/of c = MV pH= -log[H3O+] Kw = [H3O+][OH-] = 1x10-14 N ca Va na at /by 298K n= N or/of = A cb Vb nb V n= Vm 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

Downloaded from hlayiso.com (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 19 TABLE 3: THE PERIODIC TABLE OF ELEMENTS/TABEL 3: DIE PERIODIEKE TABEL VAN ELEMENTE 1 2 3 4 5 67 8 9 10 11 12 13 14 15 16 17 18 (I) (II) Atoomgetal (III) (IV) (V) (VI) (VII) (VIII) KEY/ SLEUTEL Atomic number 1 2 H He 2,1 1 29 4 Elektronegatiwiteit Simbool 3 4 1,9 Cu 5 6 7 8 9 10 Electronegativity Symbol Li Be B C N O F Ne 1,0 1,5 63,5 2,0 2,5 3,0 3,5 4,0 7 9 11 12 14 16 19 20 11 12 13 14 15 16 17 18 Na Mg Benaderde relatiewe atoommassa Aℓ Si P S Cℓ Ar 0,9 1,2 Approximate relative atomic mass 1,5 1,8 2,1 2,5 3,0 23 24 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 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 0,8 1,0 1,3 1,5 1,6 1,6 1,5 1,8 1,8 1,8 1,9 1,6 1,6 1,8 2,0 2,4 2,8 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 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 0,8 1,0 1,2 1,4 1,8 1,9 2,2 2,2 2,2 1,9 1,7 1,7 1,8 1,9 2,1 2,5 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 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tℓ Pb Bi Po At Rn 0,7 133 0,9 137 139 1,6 179 181 184 186 190 192 195 197 201 1,8204 1,8 207 1,9 209 2,0 2,5 87 88 89 Fr Ra Ac 0,7 0,9 226 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 20 PHYSICAL SCIENCES P2 (EC/SEPTEMBER 2022) TABLE 4A: STANDARD REDUCTION POTENTIALS TABEL 4A: STANDAARD REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E θ (V) F2(g) + 2e− ⇌ 2F− + 2,87 Co 3+ +e − ⇌ Co 2+ + 1,81 H2O2 + 2H+ +2e− ⇌ 2H2O +1,77 − MnO 4 + 8H+ + 5e− ⇌ Mn 2+ + 4H2O + 1,51 Cℓ2(g) + 2e − ⇌ 2Cℓ − + 1,36 2− Cr2O 7 + 14H+ + 6e− ⇌ 2Cr3+ + 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− ⇌ Increasing reducing ability/Toenemende reduserende vermoë NO(g) + 2H2O + 0,96 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 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 Sn 4+ + 2e − ⇌ Sn 2+ + 0,15 S + 2H+ + 2e− ⇌ H2S(g) + 0,14 2H+ + 2e− ⇌ H2(g) 0,00 Fe 3+ + 3e − ⇌ Fe − 0,06 Pb2+ + 2e− ⇌ Pb − 0,13 Sn2+ + 2e− ⇌ Sn − 0,14 Ni2+ + 2e− ⇌ Ni − 0,27 Co 2+ + 2e − ⇌ Co − 0,28 Cd2+ + 2e− ⇌ Cd − 0,40 Cr3+ + e− ⇌ Cr2+ − 0,41 Fe2+ + 2e− ⇌ Fe − 0,44 Cr 3+ + 3e − ⇌ Cr − 0,74 Zn2+ + 2e− ⇌ Zn − 0,76 2H2O + 2e− ⇌ H2(g) + 2OH− − 0,83 Cr2+ + 2e− ⇌ Cr − 0,91 Mn 2+ + 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 (EC/SEPTEMBER 2022) PHYSICAL SCIENCES P2 21 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 Ba2+ + 2e− ⇌ Ba − 2,90 Sr2+ + 2e− ⇌ Sr − 2,89 Ca2+ + 2e− ⇌ Ca − 2,87 Na+ + e− ⇌ Na − 2,71 Mg2+ + 2e− ⇌ Mg − 2,36 Aℓ + 3e 3+ − ⇌ Aℓ − 1,66 Mn2+ + 2e− ⇌ Mn − 1,18 ⇌ Increasing reducing ability/Toenemende reduserende vermoë Cr2+ + 2e− Cr − 0,91 2H2O + 2e− ⇌ H2(g) + 2OH− − 0,83 Increasing oxidising ability/Toenemende oksiderende vermoë Zn2+ + 2e− ⇌ Zn − 0,76 Cr3+ + 3e− ⇌ Cr − 0,74 Fe2+ + 2e− ⇌ Fe − 0,44 3+ Cr + e − ⇌ Cr 2+ − 0,41 Cd2+ + 2e− ⇌ Cd − 0,40 Co2+ + 2e− ⇌ Co − 0,28 Ni2+ + 2e− ⇌ Ni − 0,27 Sn2+ + 2e− ⇌ Sn − 0,14 2+ Pb + 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 2+ Cu + 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 2+ Hg + 2e − ⇌ Hg(ℓ) + 0,85 − NO 3 + 4H+ + 3e− ⇌ NO(g) + 2H2O + 0,96 Br2(ℓ) + 2e − ⇌ 2Br − + 1,07 Pt2+ + 2 e− ⇌ 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− ⇌ Mn + 4H2O2+ + 1,51 H2O2 + 2H +2 e + − ⇌ 2H2O +1,77 Co3+ + e− ⇌ Co2+ + 1,81 F2(g) + 2e − ⇌ 2F − + 2,87 Copyright reserved