Technical Sciences Grade 12 P2 NSC November 2020 QP (Eng)

Downloaded from hlayiso.com SENIOR CERTIFICATE/ NATIONAL SENIOR CERTIFICATE GRADE 12 TECHNICAL SCIENCES P2 NOVEMBER 2020 MARKS: 150 TIME: 3 hours This question paper consists of 15 pages and 4 data sheets. Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 2 DBE/November 2020 SC/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 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 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 2020 SC/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 1.10) in the ANSWER BOOK, e.g. 1.11 D. 1.1 Which ONE of the structural formulae below represents a secondary alcohol? A B H H H H H H H O H H C C C C O H H C C C C H H H H H H H H H C D H H H O H H C H H H H H C C C C H H C C C C H H H H H O H H H (2) 1.2 To which homologous series does dichloromethane belong? A Alkanes B Alcohols C Haloalkanes D Carboxylic acids (2) 1.3 In which ONE of the options below are the intermolecular forces arranged from the weakest to the strongest? A Hydrogen bonds, dipole-dipole forces, London forces B Hydrogen bonds, London forces, dipole-dipole forces C Dipole-dipole forces, London forces, hydrogen bonds D London forces, dipole-dipole forces, hydrogen bonds (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 4 DBE/November 2020 SC/NSC 1.4 Alkenes react with hydrogen to form … A alkanes. B alcohols. C aldehydes. D alkynes. (2) 1.5 In an electrolytic cell the cations will migrate to the … A cathode and undergo reduction. B anode and undergo oxidation. C cathode and undergo oxidation. D anode and undergo reduction. (2) 1.6 In the cell notation of a galvanic cell, the double vertical lines (//) represent a/the … A phase separator. B solid electrode. C gas electrode. D salt bridge. (2) 1.7 Consider the statements below when an incident light ray is reflected from a flat surface. (i) The angle of incidence is equal to the angle of reflection. (ii) The angle measured between the surface and the incident ray is the incidence angle. (iii) The incidence angle is the angle formed between the incident ray and the normal. Which statement(s) is/are TRUE? A (i) and (ii) B (i) and (iii) C (ii) only D (i) only (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 5 DBE/November 2020 SC/NSC 1.8 The diagram below shows light ray LM incident on a rectangular glass prism. Which ONE of the following represents the CORRECT emergent ray? A OS B NR C NQ D NP (2) 1.9 During the dispersion of white light, which colour in the visible spectrum has the smallest angle of refraction? A Green B Violet C Red D Orange (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 6 DBE/November 2020 SC/NSC 1.10 A learner used a lens (X) to focus the image of a well-illuminated faraway building on a screen (S), as shown in the diagram below. This lens is … A concave of focal length 4 cm. B convex of focal length 4 cm. C concave of focal length 8 cm. D convex of focal length 8 cm. (2) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 7 DBE/November 2020 SC/NSC QUESTION 2 (Start on a new page.) Organic molecules can be classified into different homologous series that are identified by their functional groups. 2.1 Define the term functional group. (2) 2.2 Consider the organic molecules in the table below and answer the questions that follow. H H H H H O A But-2-ene B H C C C C C C H H H H H H H H O C H C C C O D Pentan-2-one H H H Write down the NAME of the homologous series of compounds represented by: 2.2.1 A (1) 2.2.2 B (1) 2.2.3 C (1) 2.3 Write down the IUPAC name of the organic compounds represented by: 2.3.1 B (2) 2.3.2 C (2) 2.4 Draw the structural formulae of the organic compounds represented by: 2.4.1 A (2) 2.4.2 D (2) 2.5 Draw the structural formulae of the ISOMER of the organic compounds represented by: 2.5.1 A (2) 2.5.2 C (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 8 DBE/November 2020 SC/NSC 2.6 Identify the TYPE of isomer in: 2.6.1 QUESTION 2.5.1 (1) 2.6.2 QUESTION 2.5.2 (1) 2.7 Consider compound A. 2.7.1 Is compound A saturated or unsaturated? (1) 2.7.2 Explain the answer to QUESTION 2.7.1. (1) [21] QUESTION 3 (Start on a new page.) The table below shows organic molecules with different molar masses and vapour pressures. MOLAR MASS VAPOUR PRESSURE COMPOUND (g•mol-1) (x 102 Pa) 1-propanol 60 21,0 1-butanol 74 6,2 1-pentanol 88 2,2 3.1 Define the term vapour pressure. (2) 3.2 Use the table above to answer questions that follow. 3.2.1 Describe the trend in the vapour pressure of the compounds above. (1) 3.2.2 Explain the answer to QUESTION 3.2.1. Refer to CHAIN LENGTH/MOLAR MASS, STRENGTH OF INTERMOLECULAR FORCES and ENERGY. (3) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 9 DBE/November 2020 SC/NSC 3.3 Consider the graph below that indicates the boiling points of alkanes and aldehydes. 3.3.1 Identify the homologous series represented by graphs A and B respectively. (2) 3.3.2 Explain the difference in the boiling points of the two homologous series represented by graphs A and B. Refer to the TYPE and STRENGTH of the intermolecular forces. (3) [11] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 10 DBE/November 2020 SC/NSC QUESTION 4 (Start on a new page.) Use the flow diagram below to answer the questions that follow. H H H H A C C H C C OH H H H H B C Bromoethane 4.1 Write down the NAME or TYPE of reaction represented by the following letters: 4.1.1 A (1) 4.1.2 B (1) 4.1.3 C (1) 4.2 Apart from the alkene, another reactant and a catalyst are needed in reaction A. Write down the NAME or FORMULA of the: 4.2.1 Other reactant (1) 4.2.2 Catalyst (1) 4.3 Use STRUCTURAL FORMULAE to write down a balanced chemical equation for reaction B. (3) 4.4 Write TWO reaction conditions for reaction C. (2) 4.5 Use molecular formulae to write down a balanced equation for the reaction of the alkene in the flow diagram in excess oxygen. (3) 4.6 Write down the NAME of the organic compound in the flow diagram that can be used as a monomer of polythene. (1) [14] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 11 DBE/November 2020 SC/NSC QUESTION 5 (Start on a new page.) The diagram below represents the electrolysis of copper(ll) chloride. Copper(II) chloride 5.1 Define the term electrolysis. (2) 5.2 Is the electrolysis of copper(II) chloride a spontaneous or a non-spontaneous reaction? (1) 5.3 Explain the answer to QUESTION 5.2. (1) 5.4 Write down the FORMULA of an electrolyte used in the cell above. (1) 5.5 At which electrode will the following observations be made? Write down only ANODE or CATHODE. 5.5.1 Gas bubbles are formed. (1) 5.5.2 A brownish deposit is formed. (1) 5.6 Define the term reducing agent. (2) 5.7 For the cell above, write down the: 5.7.1 Oxidation half-reaction (2) 5.7.2 Reduction half-reaction (2) 5.7.3 Net reaction (2) [15] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 12 DBE/November 2020 SC/NSC QUESTION 6 (Start on a new page.) 6.1 The cell notation Zn(s)|Zn2+ (aq)║Cu2+ (aq)|Cu(s) represents a galvanic cell operating under standard conditions. 6.1.1 Define the term galvanic cell. (2) 6.1.2 Draw a labelled diagram to represent the Zn-Cu cell. Show the direction of electron flow in the external circuit. (5) 6.1.3 Write down TWO standard conditions under which the Zn-Cu cell operates. (2) 6.1.4 To which half-cell do the anions in the salt bridge migrate? (1) 6.1.5 Explain the answer to QUESTION 6.1.4. (2) 6.2 The anode in the Zn-Cu cell is replaced by an unknown electrode, X. The voltmeter gives a reading of 2,00 V. 6.2.1 Identify electrode X by means of a calculation. (5) 6.2.2 Write down the half-reaction taking place at the anode. (2) 6.2.3 Which electrode will experience a decrease in mass? (1) 6.2.4 Explain the answer to QUESTION 6.2.3. (2) [22] QUESTION 7 (Start on a new page.) 7.1 The diagram below shows the reflection of a light ray that strikes a flat mirror with a 30° angle of incidence. Line M 7.1.1 What is reflection? (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 13 DBE/November 2020 SC/NSC Use the diagram to write down the NAMES of: 7.1.2 Ray AO (1) 7.1.3 Ray OB (1) 7.1.4 Line M (1) 7.1.5 Angle 1 (1) 7.1.6 Angle 2 (1) 7.2 What is the magnitude of angle 2? (1) 7.3 How will the speed of light be affected when a light ray travels from air into water, perpendicular to the surface? (1) 7.4 A light ray enters the water from air at an angle. 7.4.1 Which medium, air or water, has the higher optical density? (1) 7.4.2 What will happen to the DIRECTION of the light ray as it enters the water? (1) 7.4.3 Write down the NAME of the phenomenon in QUESTION 7.4.2. (1) 7.5 A ray of light moves from water towards air and strikes the interfase (boundary) at an angle of incidence smaller than the critical angle. 7.5.1 Define the term critical angle. (2) 7.5.2 What observation will be made? (2) The incident angle in QUESTION 7.5 is changed such that the ray undergoes total internal reflection. 7.5.3 Describe the phenomenon total internal reflection. (2) 7.5.4 Is the incident angle GREATER THAN or SMALLER THAN the critical angle? (1) [19] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 14 DBE/November 2020 SC/NSC QUESTION 8 (Start on a new page.) 8.1 Define the term dispersion. (2) 8.2 Name any FOUR colours in visible light. (4) 8.3 State THREE properties of the image formed in a plane mirror. (3) 8.4 Redraw the diagrams below in the ANSWER BOOK and complete EACH to show the path of the ray after passing through the lens. 8.4.1 (1) 8.4.2 (2) 8.4.3 (2) [14] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 15 DBE/November 2020 SC/NSC QUESTION 9 Start on a new page.) 9.1 Define an electromagnetic wave. (2) 9.2 Which property of radio waves makes it suitable to transmit a signal over long distances? (1) 9.3 What is a photon? (1) 9.4 Write down the NAME of the electromagnetic wave that is used: 9.4.1 To detect counterfeit notes (1) 9.4.2 To open and close automatic doors (1) 9.4.3 In navigation systems (1) 9.5 What is the relationship between the frequency of light and its wavelength? (2) 9.6 Calculate the energy of light with a wavelength of 4,06 x 10-11 m. (5) [14] TOTAL: 150 Copyright reserved

Downloaded from hlayiso.com Technical Sciences/P2 DBE/November 2020 SC/NSC DATA FOR TECHNICAL SCIENCES GRADE 12 PAPER 2 GEGEWENS VIR TEGNIESE WETENSKAPPE GRAAD 12 VRAESTEL 2 TABLE 1: PHYSICAL CONSTANTS NAME SYMBOL VALUE Standard pressure p 1,01 x 105 Pa Standard temperature T 0 oC/273 K Speed of light in a vacuum c 3,0 x 108 m·s-1 Planck's constant h 6,63 x 10-34 J·s TABLE 2: WAVES, SOUND AND LIGHT 1 vf T f c E  hf or E  h  TABLE 3: FORMULAE Eθcell  Eθcathode  Eθanode Eθcell  Ereduction θ  Eθoxidation Eθcell  Eθoxidisingagent  Ereducing θ agent Copyright reserved

Technical Sciences/P2 Downloaded from hlayiso.com DBE/November 2020 SC/NSC TABLE 4: THE PERIODIC TABLE OF ELEMENTS TABEL 4: 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 2020 SC/NSC TABLE 5A: 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  MnO 4 + 8H + 5e + 1,51 2+ + ⇌ Mn + 4H2O   Cℓ2(g) + 2e ⇌ 2Cℓ + 1,36 2 Cr2O 7 + 14H + 6e + 1,33 3+ + ⇌ 2Cr + 7H2O  O2(g) + 4H + 4e + ⇌ 2H2O + 1,23 MnO2+ 4H + 2e 2+ + ⇌ Mn + 2H2O + 1,23 Pt + 2e ⇌ 2+ Pt + 1,20 Br2(ℓ) + 2e ⇌ 2Br + 1,07  NO 3 + 4H + 3e + 0,96 + ⇌ NO(g) + 2H2O  2+ Hg + 2e ⇌ Hg(ℓ) + 0,85 Ag + e ⇌ + Ag + 0,80  NO 3 + 2H + e + 0,80 + ⇌ NO2(g) + H2O  2+ 3+ Fe + e ⇌ 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 ⇌ + S + 2H2O + 0,45 Increasing oxidising ability 2H2O + O2 + 4e ⇌ 4OH + 0,40 Cu + 2e ⇌ 2+ Cu + 0,34 2 SO 4 + 4H + 2e ⇌ + 0,17 + 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 K + e ⇌  2,93 + K Li + e ⇌  3,05 + Li Copyright reserved

Downloaded from hlayiso.com Technical Sciences/P2 DBE/November 2020 SC/NSC TABLE 5B: 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 Increasing oxidising ability Cd + 2e ⇌  0,40 2+ Cd Co + 2e ⇌  0,28 2+ Increasing reducing ability 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 Cr2O 7 + 14H + 6e 3+ + ⇌ 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