Technical Sciences P2 Nov 2022 Eng hlayiso.com

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 TECHNICAL SCIENCES P2 NOVEMBER 2022 MARKS: 75 TIME: 1½ hours This question paper consists of 9 pages and 4 data sheets. Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 2 DBE/November 2022 NSC INSTRUCTIONS AND INFORMATION 1. Write your centre number and examination number in the appropriate spaces on the ANSWER BOOK. 2. This question paper consists of SIX 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 are advised to use the attached DATA SHEETS. 8. Round off your FINAL numerical answers to a minimum of TWO decimal places. 9. Give brief motivations, discussions, etc. where required. 10. Write neatly and legibly. Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 3 DBE/November 2022 NSC 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 1.5) in the ANSWER BOOK, e.g. 1.6 D. 1.1 Which ONE of the compounds below represents a saturated hydrocarbon? A C3H6 B C4H8 C C5H12 D C6H10 (2) 1.2 Consider the structural formulae of the alcohols below. (i) (ii) H H H H H H C C O H C C C H H O H H H H H (iii) (iv) H H H C H O H H H H H H C C C C H H C C C H H H H H H O H H Which ONE of the following combinations represents a secondary alcohol? A (ii), (iii) and (iv) B (i) and (iv) C (ii) and (iv) D (i) only (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 4 DBE/November 2022 NSC 1.3 … are examples of PURE SEMICONDUCTORS. A Diamonds, silicon and germanium B Germanium, copper and lead C Silicon, germanium and lead D Diamonds, silicon and krypton (2) 1.4 Electroplating is a common application of electrolysis. Which ONE of the following is NOT used for electroplating metals? A To enhance the appearance B To make it stronger C To increase the value D To prevent rusting (2) 1.5 The net cell reaction taking place in a fuel cell is 2H2(g) + O2(g) 2H2O(ℓ) + energy This is a/an … A electrolytic cell and the reaction is endothermic. B electrolytic cell and the reaction is exothermic. C galvanic cell and the reaction is endothermic. D galvanic cell and the reaction is exothermic. (2) [10] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 5 DBE/November 2022 NSC QUESTION 2 (Start on a new page.) The table below represents organic molecules with different functional groups. H H Br H H C C C C H H H O A H H H B H C C C O H C H H H H H H O H H C Methyl ethanoate D H C C C C H H H H H H H H E H C C C C H F Prop-1-ene H H H H 2.1 Define the term homologous series. (2) 2.2 Write down the letter (A–F) that represents the following: 2.2.1 Haloalkane (1) 2.2.2 Functional isomers (2) 2.2.3 Ketone (1) 2.2.4 Unsaturated hydrocarbon (1) 2.3 Write down the IUPAC name of compound E. (2) 2.4 Draw the structural formula of the following: 2.4.1 Compound C (2) 2.4.2 Functional group of compound F (2) [13] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 6 DBE/November 2022 NSC QUESTION 3 (Start on a new page.) The graph below shows the boiling points of three different compounds represented by the letters A, B and C. These compounds are from different homologous series. A B C 3.1 Define the term boiling point. (2) 3.2 Which ONE of the compounds above contains the weakest type of intermolecular force? (1) In no specific order, the above compounds are identified as propan-1-ol, propanal and propanoic acid. 3.3 Write down the NAMES of the compounds above represented by the following letters: 3.3.1 A (1) 3.3.2 B (1) 3.3.3 C (1) 3.4 Explain the difference in the vapour pressure of propanoic acid and propan-1-ol. Refer to the TYPE OF INTERMOLECULAR FORCES, STRENGTH OF THE INTERMOLECULAR FORCES and the ENERGY NEEDED. (4) 3.5 Which compound has the highest melting point? Write down only A, B or C. (1) [11] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 7 DBE/November 2022 NSC QUESTION 4 (Start on a new page.) Consider the flow diagram below that shows different organic reactions. Ethene Reaction 1 Reaction 3 Reaction 2 Chloroethane Compound X + H2O + H2O Compound Y + HCℓ 4.1 Write down the TYPE of reaction represented by the following: 4.1.1 Reaction 1 (1) 4.1.2 Reaction 3 (1) 4.2 Using molecular formulae, write down a balanced chemical equation for reaction 1. (3) 4.3 Excess oxygen is the other reactant in reaction 2. 4.3.1 Identify the type of reaction. (1) 4.3.2 Write down the NAME or FORMULA of compound X. (2) 4.4 Chloroethane reacts with water to form compound Y. Write down the following for this reaction: 4.4.1 The type of reaction (1) 4.4.2 TWO reaction conditions (2) 4.4.3 The NAME of compound Y (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 8 DBE/November 2022 NSC 4.5 Materials consisting of certain elements in group IV have electrical conductivity between conductors and insulators. 4.5.1 Write down the NAME of the materials referred to in the above statement. (1) 4.5.2 Define the term doping. (2) 4.5.3 A diode is constructed by connecting the positive terminal of the battery to a p-type material and the negative terminal to an n-type material. What type of a diode is this? Write down only FORWARD BIAS or REVERSE BIAS. (1) [17] QUESTION 5 (Start on a new page.) The diagram below represents the electrochemical cell used in the electrolysis of molten CuCℓ2. P and Q are carbon electrodes. P Q Molten CuCℓ2 5.1 Write down the magnitude of the copper charge in CuCℓ2. (1) 5.2 Define the term electrolysis. (2) 5.3 Is the reaction ENDOTHERMIC or EXOTHERMIC? (1) 5.4 Which electrode is the cathode? Write down only P or Q. (1) 5.5 Write down the observations made at the following electrodes: 5.5.1 P (1) 5.5.2 Q (1) 5.6 Write down a balanced chemical equation for the net cell reaction of the above cell. (3) 5.7 Give a reason why CuCℓ2 is used in its molten form instead of its solid state. (2) [12] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 9 DBE/November 2022 NSC QUESTION 6 (Start on a new page.) The cell notation of a standard galvanic (voltaic) cell containing an unknown metal Y is shown below. Y (s) | Y2+ (aq) || Cu2+ (aq) | Cu(s) 6.1 What do the single vertical lines (|) in the cell notation represent? (1) 6.2 State TWO standard conditions for the cell. (2) 6.3 Write down the NAME or FORMULA of the oxidising agent. (2) 6.4 Identify the polarity of the: 6.4.1 Anode (1) 6.4.2 Cathode (1) 6.5 The initial reading on a voltmeter connected across the electrodes is 1,10 V. Use a calculation to identify metal Y. (5) [12] TOTAL: 75 Copyright reserved

Downloaded from hlayiso.com Technical Sciences/P2 DBE/November 2022 NSC DATA FOR TECHNICAL SCIENCES GRADE 12 PAPER 2 GEGEWENS VIR TEGNIESE WETENSKAPPE GRAAD 12 VRAESTEL 2 TABLE 1/TABEL 1: PHYSICAL CONSTANTS/FISIESE KONSTANTES NAME/NAAM SYMBOL/SIMBOOL VALUE/WAARDE Standard pressure Standaarddruk pƟ 1,01 x 10 Pa 5 Standard temperature Standaardtemperatuur TƟ 273 K/0 °C TABLE 2/TABEL 2: FORMULAE/FORMULES Emf/Emk Ecell = Ecathode  Eanode / Esel = Ekatode  Eanode or/of Ecell = Ereduction  Eoxidation / Esel = Ereduksie  Eoksidasie or/of Ecell = Eoxidising agent  Ereducing agent / Esel = Eoksideermiddel  Ereduseermiddel Copyright reserved

Technical Sciences/P2 Downloaded from hlayiso.com DBE/November 2022 NSC 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

Downloaded from hlayiso.com Technical Sciences/P2 DBE/November 2022 NSC TABLE 4A: STANDARD REDUCTION POTENTIALS Half-reactions Eθ (V) F2(g) + 2e ⇌ 2F + 2,87 Co + e 2+ 3+ ⇌ Co + 1,81 H2O2 + 2H +2e ⇌ + 2H2O +1,77  2+ + 1,51 MnO 4 + 8H + 5e + ⇌ Mn + 4H2O   Cℓ2(g) + 2e ⇌ 2Cℓ + 1,36 2 3+ + 1,33 Cr2O 7 + 14H + 6e + ⇌ 2Cr + 7H2O  O2(g) + 4H + 4e + ⇌ 2H2O + 1,23 MnO2+ 4H + 2e 2+ + ⇌ Mn + 2H2O + 1,23  2+ Pt + 2e ⇌ Pt + 1,20 Br2(ℓ) + 2e ⇌ 2Br + 1,07  + 0,96 NO 3 + 4H + 3e ⇌ + NO(g) + 2H2O  2+ Hg + 2e ⇌ Hg(ℓ) + 0,85 Ag + e ⇌ + Ag + 0,80  + 0,80 NO 3 + 2H + e ⇌ + NO2(g) + H2O Fe + e 2+ 3+ ⇌ Fe + 0,77 O2(g) + 2H + 2e ⇌ + H2O2 + 0,68 I2 + 2e ⇌ 2I + 0,54 Cu + e ⇌ + Cu + 0,52 Increasing reducing ability SO2 + 4H + 4e ⇌ + Increasing oxidising ability S + 2H2O + 0,45 2H2O + O2 + 4e ⇌ 4OH + 0,40 Cu + 2e ⇌ 2+ Cu + 0,34 2 + 0,17 SO 4 + 4H + 2e + ⇌ SO2(g) + 2H2O  + 2+ Cu + e ⇌ 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  ⇌  2,93 + K +e K Li + e ⇌  3,05 + Li Copyright reserved

Downloaded from hlayiso.com Technical Sciences/P2 DBE/November 2022 NSC TABLE 4B: STANDARD REDUCTION POTENTIALS Half-reactions Eθ (V) Li + e ⇌  3,05 + Li K + e ⇌  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 Increasing reducing ability ⇌  0,40 2+ Cd Co + 2e Increasing oxidising ability ⇌  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  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  2+ 3+ 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 2+ 3+ ⇌ Co + 1,81 F2(g) + 2e ⇌ 2F + 2,87 Copyright reserved