Technical Sciences Grade 12 P2 GP Prelim 2023 QP (Eng)

Downloaded from hlayiso.com PREPARATORY EXAMINATION 2023 11102 TECHNICAL SCIENCES (PAPER 2) TIME: 1½ hours MARKS: 75 10 pages and 4 data sheets P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 2 (PAPER 2) 11102/23 INSTRUCTIONS AND INFORMATION 1. This question paper consists of SEVEN questions. Answer ALL the questions in the ANSWER BOOK. 2. Start EACH question on a NEW page in your ANSWER BOOK. 3. Number your answers correctly according to the numbering system used in this question paper. 4. Leave ONE line between sub-questions, for example between QUESTION 2.1 and QUESTION 2.2. 5. You may use a non-programmable scientific calculator. 6. You are advised to use the attached DATA SHEETS. 7. Show ALL formulae and substitutions in ALL calculations. 8. Round-off your FINAL numerical answers to a minimum of TWO decimal places. 9. Give brief motivations, discussions, et cetera where required. 10. Write neatly and legibly. P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 3 (PAPER 2) 11102/23 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various options are provided as possible answers to the following questions. Choose the correct answer and write only the letter (A – D) next to the question numbers (1.1 to 1.6) in the ANSWER BOOK, e.g. 1.7 D. 1.1 Which of the following compounds is a tertiary alcohol? A B C D (2) 1.2 The general formula, CnH2n, describes the following homologous series: A Alkane B Alkene C Alkyne D Haloalkane (2) 1.3 Dipole-dipole forces increase with the increase of polarity of functional groups: A Alkanes < aldehydes < esters < ketones < alcohols < carboxylic acid B Alkanes < esters < aldehydes < alcohols < ketones < carboxylic acid C Alkanes < esters < aldehydes < ketones < alcohols < carboxylic acid D Alkanes < aldehydes < ketones < alcohols < carboxylic acid < esters (2) 1.4 Which of the following types of intermolecular forces is the strongest? A London forces B Dipole-dipole forces C Van der Waals forces D Hydrogen bonds (2) P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 4 (PAPER 2) 11102/23 1.5 Which of the following statements regarding the anode of a standard galvanic cell in operation is CORRECT? A The anode accepts electrons. B The mass of the anode increases. C The concentration of the electrolyte in the half-cell containing the anode increases. D The anode is the positive terminal of the cell. (2) 1.6 A learner wants to electroplate a copper ring with nickel. He uses the experimental setup shown in the simplified diagram below. Power source Nickel rod Copper ring Electrolyte Which of the following is CORRECT? ANODE CATHODE ELECTROLYTE A Copper ring Nickel rod CuSO4 B Nickel rod Copper ring CuSO4 C Copper ring Nickel rod NiSO4 D Nickel rod Copper ring NiSO4 (2) [12] P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 5 (PAPER 2) 11102/23 QUESTION 2 (Start on a new page.) Study the following table of organic molecules as represented by letters A to F below and answer the following questions. A B C Ethyl propanoate D 3-methylbutan-2-one E F 2.1 Define a homologous series. (2) 2.2 Write down the letter(s) that represent(s) the compound that is/are: 2.2.1 Unsaturated (1) 2.2.2 An Ester (1) 2.2.3 A ketone (1) 2.2.4 Chain isomers (2) 2.3 Write down the following: 2.3.1 The structural formula of compound C (3) 2.3.2 The functional isomer of compound C (3) [13] P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 6 (PAPER 2) 11102/23 QUESTION 3 (Start on a new page.) Esters are used for its pleasant fruity odours. It is also used in paint and coating adhesives, lubricants, intermediates, processing aids and as a solvent in paint, glue, nail polish and graffiti removers. Use the table of esters below to answer the following questions. Ester Molar Mass (g.mol-1) Melting point (oC) Boiling point (oC) A HCOOCH3 60 -99 32 B HCOOCH2CH3 74 -98 57 C HCOOCH2CH2CH3 88 -88 80 3.1 Define the term boiling point. (2) 3.2 What is the difference between the esters’ molecular structures above? (2) 3.3 Explain why compound C has a higher boiling point than compound A in terms of the type of intermolecular forces, strength of these intermolecular forces and the energy needed. (3) 3.4 Which compound would have the highest vapour pressure? (1) 3.5 Explain your answer to QUESTION 3.4 above. (3) [11] P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 7 (PAPER 2) 11102/23 QUESTION 4 (Start on a new page.) The flow diagram below shows the interconversion between alcohols, alkenes and haloalkanes. The letters A – C represent addition or substitution. Compound A Compound B: Alcohol Ethene Ethane O2 Combustion Compound C 4.1 What type of reaction is represented by reaction B? Write down only ADDITION or SUBSTITUTION. (1) 4.2 Write down the name of the inorganic substance needed for this reaction to form an alcohol. (1) 4.3 Use structural formula and write down the major product of compound B. (2) 4.4 Identify the type of reaction that is represented by reaction A if HBr is added to ethene. Write down the full reaction name. (1) 4.5 Give the IUPAC name of compound A. (2) Hydrogenation is a chemical reaction where hydrogen is added to an alkene to form ethane. Ethane is considered a more efficient fuel source for fast growing and developing countries. 4.6 Write down a balanced chemical equation where ethane is burned in excess oxygen. Use molecular formula. (3) [10] P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 8 (PAPER 2) 11102/23 QUESTION 5 (Start on a new page.) Silicon is the most common semiconductor material used in solar cells, representing approximately 95% of the modules sold today. It is also the second most abundant material on earth (after oxygen) and the most common semiconductor used in computer chips. 5.1 Define intrinsic semiconductor. (2) 5.2 Write down the name of the type of material of which an intrinsic semiconductor is made and that is found between the metals and non-metals on the periodic table. (1) 5.3 Draw the symbol of a p-n type diode. (2) [5] P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 9 (PAPER 2) 11102/23 QUESTION 6 (Start on a new page.) Two different cells, A and B are shown in the diagram below. Both Cell A and Cell B contain a concentrated solution of copper(II) chloride (CuCl2). In Cell A, P is a copper electrode and Q is a carbon electrode. In cell B, both R and S are identical carbon electrodes. Carbon Carbon Carbon Copper Concentrated CuCl2(aq) Concentrated CuCl2(aq) Cell A Cell B 6.1 Are the above electrochemical cells electrolytic or galvanic? (1) 6.2 Give a reason for your answer to QUESTION 6.1. (1) 6.3 Write down the name of the electrolytic process taking place at Cell A. (1) 6.4 Give a reason for your answer to QUESTION 6.3. (1) 6.5 Write down ONE importance of the electrolytic process mentioned in QUESTION 6.3. (1) 6.6 Write down the NAME or SYMBOL of an anion in the electrolyte in Cell B. (1) 6.7 Write down the chemical equation for the half-reaction taking place at electrode Q. (2) 6.8 Write down the NAME or SYMBOL of the product formed at electrode R. (1) 6.9 What happens to the concentration of the electrolyte in Cell B when the cell is in operation? Write down INCREASES, DECREASES, or REMAINS THE SAME. Give a reason for your answer. (3) [12] P.T.O.

Downloaded from hlayiso.com TECHNICAL SCIENCES 10 (PAPER 2) 11102/23 QUESTION 7 (Start on a new page.) Grade 12 learners performed an experiment to determine the electrode potential of a zinc-copper cell. They assembled the apparatus as shown in the diagram below. The experiment was performed at an initial concentration of 1 molꞏdm-3 and a temperature of 25 oC. 7.1 Define galvanic cell. (2) 7.2 Give a reason why the standard condition of the pressure of 101,3 kPa is not applicable to the zinc-copper cell. (1) 7.3 Use a calculation to show that this electrochemical cell is spontaneous. (4) 7.4 Write down the overall (net) cell reaction for this cell. (3) 7.5 The voltmeter is now replaced with a 2V bulb. Will the bulb glow to its maximum brightness? Answer YES or NO and give a reason for your answer. (2) [12] TOTAL: 75 END

Downloaded from hlayiso.com TECHNICAL SCIENCES 11 (Paper 2) 11102/23 DATA FOR TECHNICAL SCIENCES GRADE 12/ GEGEWENS VIR TEGNIESE WETENSKAPPE GRAAD 12 PAPER/VRAESTEL 2 TABLE/TABEL 1 PHYSICAL CONSTANTS/FISIESE KONSTANTES CONSTANT/KONSTANTE SYMBOL/SIMBOOL VALUE/WAARDE Planck's constant Planck se konstante h 6,63 x 10-34 J.s Speed of light Spoed van lig c 3 x 108 m.s-1 TABLE/TABEL 2 WAVES, SOUND AND LIGHT/GOLWE, KLANK EN LIG Speed/Spoed c=fλ Energy/Energie E = hf or/of hc E= λ TABLE/TABEL 3 ELECTROCHEMISTRY/ELEKTROCHEMIE Emf/Emk E θcell  E θcathode  E θanode / E θsel  E katode θ  E θanode or/of E θcell  E reduction θ  E θoxidation / E θsel  E reduksie θ  E θoksidasie or/of Eθcell  Eθoxidising agent  Eθreducing agent θ / Esel  Eθoksideermi ddel  Eθreduseermi ddel

Downloaded from hlayiso.com TECHNICAL SCIENCES 12 (PAPER 2) 11102/23 TABLE 4A: STANDARD REDUCTION POTENTIALS/ TABEL 4A: STANDAARD-REDUKSIEPOTENSIALE Eθ Half-reactions/Halfreaksies (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  ⇌ 2Cr 3+ + 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 oxidising ability/Toenemende oksiderende vermoë ⇌ NO(g) + 2H2O + 0,96 Increasing reducing ability/Toenemende reduserende vermoë 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

Downloaded from hlayiso.com TECHNICAL SCIENCES 13 (PAPER 2) 11102/23 TABLE 4B: STANDARD REDUCTION POTENTIALS/ TABEL 4B: STANDAARD-REDUKSIEPOTENSIALE E θ Half-reactions/Halfreaksies (V) Li+ + e ⇌ Li  3,05 K+ + e ⇌ K  2,93 Increasing reducing ability/Toenemende reduserende vermoë Cs+ + e ⇌ Cs  2,92 Increasing oxidising ability/Toenemende oksiderende vermoë 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 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+ + 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 ⇌ Mn2+ + 4H2O + 1,51 H2O2 + 2H+ +2 e ⇌ 2H2O +1,77 Co3+ + e ⇌ Co2+ + 1,81 F2(g) + 2e ⇌ 2F + 2,87

Downloaded from hlayiso.com TECHNICAL SCIENCES 14 (Paper 2) 11102/23 TABLE 5: THE PERIODIC TABLE OF ELEMENTS/TABEL 5: 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) Atomic number/ (III) (IV) (V) (VI) (VII) (VIII) KEY/SLEUTEL 1 Atoomgetal 2 2,1 H He 1 29 4 3 4 Electronegativity/ 1,9 Cu Symbol/ 5 6 7 8 9 10 1,0 Li 1,5 Be Elektronegatiwiteit 63,5 Simbool 2,0 B 2,5 C 3,0 N 3,5 O 4,0 F Ne 7 9 11 12 14 16 19 20 11 12 Approximate relative atomic mass/ 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 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