Technical Sciences Grade 12 P2 Gauteng Mock 2020 QP (Eng)

GAUTENG DEPARTMENT OF EDUCATION PREPARATORY EXAMINATION 2020 TECHNICAL SCIENCES PAPER 2 11102 TIME: 3 hours MARKS: 150 20 pages + 3 data sheets P.T.O.

TECHNICAL SCIENCES 2 (Paper 2) 11102/20 INSTRUCTIONS AND INFORMATION 1. Write your name in the appropriate space 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. Write neatly and legibly. 7. You may use a non-programmable calculator. 8. You may use appropriate mathematical instruments. 9. You are advised to use the attached data sheets. 10. Show ALL formulae and substitutions in ALL calculations. 11. Round-off your FINAL numerical answers to a minimum of TWO decimal places. 12. Give brief motivations, discussions, et cetera where required. P.T.O.

TECHNICAL SCIENCES 3 (Paper 2) 11102/20 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Four options are provided as possible answers to the following questions. Each question has only ONE correct answer. Write only the letter (A – D) next to the question number (1.1 to 1.10) in the ANSWER BOOK. 1.1 To which functional group does methyl ethanoate belong? A Esters B Alcohols C Aldehydes D Carboxylic acids (2) 1.2 Which of the four organic compounds below belongs to carbonyl group? A Pentane B Pentanol C Pentanone D Pentanoic acid (2) 1.3 Which of the following, lists the intermolecular forces from the lowest to the highest boiling point required to overcome them? A Van der Waals, dipole-dipole, single hydrogen, double hydrogen B Double hydrogen, single hydrogen, dipole-dipole, van der Waals C Single hydrogen, double hydrogen, dipole-dipole, van der Waals D Dipole-dipole, van der Waals, single hydrogen, double hydrogen (2) P.T.O.

TECHNICAL SCIENCES 4 (Paper 2) 11102/20 1.4 In the flow diagram below, the structural formula of P is … A B C D (2) P.T.O.

TECHNICAL SCIENCES 5 (Paper 2) 11102/20 QUESTIONS 1.5 to 1.7 are based on the diagram below which represents the purification of copper. 1.5 The correct statement about the cell represented above is: A It is an electrolytic cell and electrode B is the cathode. B It is an electrolytic cell and electrode A is the anode. C It is a galvanic cell and electrode A is the cathode. D It is a galvanic cell and electrode B is the anode. (2) 1.6 Which of the following statements is CORRECT for this process? A Cu is oxidised to copper ions at B. B Cu is reduced to copper ions at B. C Cu2+ ions are reduced to copper at B. D Cu2+ ions are oxidised to copper at A. (2) 1.7 The most suitable electrolyte to be used in this reaction is … A Zinc Sulphate. B Copper Sulphate. C Magnesium Sulphate. D Aluminium Sulphate. (2) P.T.O.

TECHNICAL SCIENCES 6 (Paper 2) 11102/20 1.8 Which of the following is TRUE when light rays are reflected from a surface? I. The angle of incidence is equal to the angle of reflection for reflections from flat surfaces. II. The angle measured between the surface and the ray is the same magnitude as the angle of reflection III. The angle of incidence is found by subtracting the angle made with the surface from the normal A I and II B I and III C II only D I only (2) 1.9 When a ray of white light is shone onto a triangular glass prism, it spreads into the seven colours of the spectrum. Which colour of the visible spectrum would have the smallest angle of refraction? A Red B Green C Violet D Orange (2) 1.10 Which of the following forms of alternative energies is most commonly used in South Africa? A Biodiesel B Hydro energy C Nuclear energy D Photovoltaic cell (2) [20] P.T.O.

TECHNICAL SCIENCES 7 (Paper 2) 11102/20 QUESTION 2 (Start on a new page.) The letters A to F in the table below represent six organic compounds. Use these compounds to answer the questions that follow. A B C D Methanal E F P.T.O.

TECHNICAL SCIENCES 8 (Paper 2) 11102/20 2.1 Define the term functional group. (2) 2.2 Write down the letter(s) representing organic molecules that is/are an … 2.2.1 alkene (1) 2.2.2 aldehyde (1) 2.3 Write down IUPAC names of organic molecules represented by the following letters: 2.3.1 B (2) 2.3.2 C (2) 2.3.3 E (2) 2.4 Write down the: 2.4.1 Structural formula of compound D. (2) 2.4.2 General formula of compound A. (2) 2.5 To which homologous series do organic molecules represented by the following letters belong? 2.5.1 B (1) 2.5.2 F (1) 2.6 Many of the plastics we use in everyday life and in industry are made from long chains of monomers. Define a monomer. (2) [18] P.T.O.

TECHNICAL SCIENCES 9 (Paper 2) 11102/20 QUESTION 3 (Start on a new page.) As a liquid evaporates, the vapours on the surface of the liquid exert a vapour pressure. Vapour pressure varies with the liquid's temperature. If atmospheric pressure changes, a liquid's boiling point will also change. The graph below illustrates the relationship between vapour pressure and temperature for TWO organic compounds belonging to the alkane group. Vapour pressure/mmHg 3.1 Define the term vapour pressure. (2) 3.2 Write down the TYPE of intermolecular forces between organic molecules mentioned in the graph above. (1) 3.3 Explain the trend in the boiling points of the two organic molecules shown in the graph above. (3) 3.4 Explain the relationship between the vapour pressure and the boiling point in the graph above. (2) P.T.O.

TECHNICAL SCIENCES 10 (Paper 2) 11102/20 3.5 The picture below illustrates how much easier it is to pour water than to pour syrup into a container. 3.5.1 Which property of the two liquids is responsible for the manner in which they flow into the container? (1) 3.5.2 Explain the difference in the manner in which the water and syrup flow into the containers. (3) [12] P.T.O.

TECHNICAL SCIENCES 11 (Paper 2) 11102/20 QUESTION 4 (Start on a new page.) 4.1 Ethyne is the gas used in oxyacetylene blow torches during the cutting and welding of metals. Write down the balanced equation for the reaction above in sufficient oxygen. (3) 4.2 Compound 1 is an alkene and can undergo addition reaction which is widely used in the industry. The flow diagram below shows the different addition reactions of COMPOUND 1. Primary Alcohol Compound 3 Reaction A Reaction B Compound 1 Reaction D Reaction C 1,2-dibromopropane Compound 4 Write down the IUPAC name of organic molecules represented by: 4.2.1 Compound 3 (2) 4.2.2 Compound 4 (2) P.T.O.

TECHNICAL SCIENCES 12 (Paper 2) 11102/20 4.3 Write down NAMES of addition reaction represented by … 4.3.1 Reaction A. (1) 4.3.2 Reaction B. (1) 4.3.3 Reaction C. (1) 4.3.4 Reaction D. (1) 4.4 Use structural formulae to represent: 4.4.1 Reaction B forming the primary alcohol (3) 4.4.2 Reaction C forming 1,2-dibromopropane (3) [17] P.T.O.

TECHNICAL SCIENCES 13 (Paper 2) 11102/20 QUESTION 5 (Start on a new page.) The diagram below illustrates how a Hydrogen Fuel Cell produces electrical energy directly from a chemical reaction just like a galvanic cell. Hydrogen is oxidized to protons at the anode, and oxygen is reduced and combines to form water. 5.1 What energy conversion takes place in the Hydrogen represented in the diagram above? (2) 5.2 At which electrode, A or B, does oxidation occur? (1) 5.3 Which substance in the cell in the diagram above is a reducing agent? (2) 5.4 Write down the following reactions for the cell in the diagram above. 5.4.1 Reduction half reaction (2) 5.4.2 Overall net cell reaction (3) 5.4.3 Calculate the emf of the cell in the diagram above. (4) 5.5 Mention THREE standard conditions of a galvanic cells. (3) [17] P.T.O.

TECHNICAL SCIENCES 14 (Paper 2) 11102/20 QUESTION 6 (Start on a new page.) Gold plating is done using an electrolytic cell where a thin layer of gold is deposited onto the surface of another metal. A group of technical scientists bought a basic kit comprising of the apparatus below to perform an experiment on electroplating a metal spoon. Connecting wires A gold electrolyte A gold electrode A metal spoon A power supply A switch 6.1 Define the term electrolytic cell. (2) 6.2 The success of the experiment depends on the correct connection of the gold electrode and the metal spoon. 6.2.1 Draw a fully-labelled diagram to show the correct connection of an electrolytic cell that will result in the gold plating of the metal spoon. Show the positive and the negative terminal of the power supply. (6) 6.2.2 Is gold plating a spontaneous or a non-spontaneous reaction? (1) 6.2.3 Explain the answer to QUESTION 6.2.2 (2) 6.2.4 Which electrode is the anode? Write only METAL SPOON/GOLD ELECTRODE. (1) 6.2.5 Briefly explain how the metal spoon gets electroplated with gold. (2) 6.2.6 Write down TWO reasons why gold plating is preferred in jewellery production. (2) P.T.O.

TECHNICAL SCIENCES 15 (Paper 2) 11102/20 6.3 Due to challenges with the economy and high petrol and diesel prices, the alternative way for people to fuel their cars might be the production of cars that use a fuel cell as a power source, such as the one shown below. In fuel cells, the only two products used are water and electricity. Mention at least TWO advantages of using the fuel cell car shown above. (2) [18] P.T.O.

TECHNICAL SCIENCES 16 (Paper 2) 11102/20 QUESTION 7 (Start on a new page.) Two light rays originating from points P on an object are reflected by a flat mirror into the eye of an observer in the diagram below. The reflected rays are obtained by using the law of reflection. 7.1 State the law of reflection. (2) 7.2 Write down THREE properties of the image observed. (3) 7.3 Is the image formed real or virtual? (1) 7.4 Light can also undergo total internal reflection. 7.4.1 Write down TWO conditions for total internal reflection. (2) 7.4.2 Write down TWO optical instruments that use total internal reflection. (2) 7.4.3 Draw a simple, labelled diagram representing total internal reflection. (5) [15] P.T.O.

TECHNICAL SCIENCES 17 (Paper 2) 11102/20 QUESTION 8 (Start on a new page.) 8.1 Look at the diagram below and answer the questions that follow. 8.1.1 Which phenomenon best explains the difference in the image of the pencil observed in the water. (1) 8.1.2 Explain why the image of the pencil in the water that is observed in glass A is different from the image observed in glass B. (4) 8.2 When a ray of light passes through a triangular glass prism, the light ray spreads into seven (7) colours. 8.2.1 Write down the name of the phenomenon where white light spreads into its seven component colours. (1) 8.2.2 Define the phenomenon in QUESTION 8.2.1. (2) 8.2.3 Write down the seven component colours in order of increasing frequencies. (7) [15] P.T.O.

TECHNICAL SCIENCES 18 (Paper 2) 11102/20 QUESTION 9 (Start on a new page.) After the age of 40 most people find it difficult to see nearby objects. To correct this, doctors recommend glasses with a lens that can allow them to see objects that are near. 9.1 Write down the names of TWO types of lenses. (2) 9.2 Write down the NAME of the eye condition when a person cannot see nearby objects. (1) 9.3 Which type of lens can be used to correct the condition mentioned in QUESTION 9.2. (1) 9.4 Write down the NAME of the eye condition which is the opposite of the one mentioned in QUESTION 9.2. (1) 9.5 Which type of lens can be used to correct the condition mentioned in QUESTION 9.4. (1) [6] P.T.O.

TECHNICAL SCIENCES 19 (Paper 2) 11102/20 QUESTION 10 (Start on a new page.) 10.1 Define the term electromagnetic waves. (2) 10.2 Identify the TYPES of electromagnetic waves associated with the uses in the table below. (3) A Early detection of cancer and dementia B Detecting counterfeit bank notes P.T.O.

TECHNICAL SCIENCES 20 (Paper 2) 11102/20 C Detecting broken bones 10.3 The equation E = hf is used to calculate the energy of a photon 10.3.1 Define the term photon. (2) 10.3.2 Calculate the energy of light of which the wavelength is 4,06 x 10-11 m. (5) [12] TOTAL: 150 END

TECHNICAL SCIENCES 21 (Paper 2) 11102/20 DATA FOR TECHNICAL SCIENCES GRADE 12 PAPER 2 GEGEWENS VIR TEGNIESE WETENSKAPPE GRAAD 12 VRAESTEL 2 TABLE 1 / TABEL 1: PHYSICAL CONSTANTS / FISIESE KONSTANTES PHYSICAL CONSTANTS / FISIESE KONSTANTES CONSTANT / KONSTANTE SYMBOL / SIMBOOL VALUE / WAARDE Standard pressure Standaarddruk pƟ 1,01 x 10 Pa 5 Standard temperature Standaard temperatuur TƟ 298 K/25 0C Speed of light Spoed van lig c 3 x 108 m.s-1 Planck's constant Planck se konstante h 6,63 x 10-34 J.s TABLE 2 / TABEL 2: WAVES, SOUND AND LIGHT / GOLWE, KLANK EN LIG 1 𝑣 = 𝑓𝜆 T= 𝑓 𝑐 E = hf or / of E = h 𝜆 TABLE 3 / TABEL 3: ELECTROCHEMISTRY / ELEKTROCHEMIE Emf / Emk Eθcell = Eθcathode − Eθanode / Eθsel = Ekatode θ − Eθanode or / of Eθcell = Ereduction θ − Eθoxidation / Eθsel = Ereduksie θ − Eθoksidasie or / of Eθcell = Eθoxidisingagent − Ereducing θ agent / Esel = Eoksideermiddel − Ereduseermiddel θ θ θ

TECHNICAL SCIENCES 22 (Paper 2) 11102/20 TABLE 4A: STANDARD REDUCTION POTENTIALS TABEL 4A: STANDAARD-REDUKSIEPOTENSIALE Half-reactions/Halfreaksies Eθ (V) − ⇌ − + 2,87 F2(g) + 2e 2F 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− ⇌ 2Cr3+ + 7H2O + 1,33 O2(g) + 4H+ + 4e− ⇌ 2H2O + 1,23 MnO2 + 4H+ + 2e− ⇌ Mn2+ + 2H2O + 1,23 2+ − ⇌ Pt + 1,20 Pt + 2e Br2(ℓ) + 2e− ⇌ 2Br− + 1,07 NO 3− + 4H+ + 3e− ⇌ NO(g) + 2H2O + 0,96 Hg2+ + 2e− ⇌ Hg(ℓ) + 0,85 Increasing oxidising ability / Toenemende oksiderende vermoë Ag+ + e− ⇌ Increasing reducing ability / Toenemende reduserende vermoë 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

TECHNICAL SCIENCES 23 (Paper 2) 11102/20 TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD-REDUKSIEPOTENSIALE Eθ (V) Half-reactions/Halfreaksies Li+ + e− ⇌ Li − 3,05 K+ + e− ⇌ K − 2,93 Cs+ + e− ⇌ Cs − 2,92 Ba2+ + 2e− ⇌ Ba − 2,90 Increasing reducing ability/Toenemende reduserende vermoë Sr2+ + 2e− − 2,89 Increasing oxidising ability/Toenemende oksiderende vermoë ⇌ Sr 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