Technical Sciences Grade 12 P2 North West Mock 2019 QP (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 TECHNICAL SCIENCES P2 SEPTEMBER 2019 MARKS: 150 TIME: 3 hours This question paper consists of 13 pages and 4 data sheets. Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 2 NW/September 2019 NSC INSTRUCTIONS AND INFORMATION 1. This question paper consists of NINE questions. Answer ALL the questions in the ANSWER BOOK. 2. Start EACH question on a NEW page in the ANSWER BOOK. 3. Number the answers correctly according to the numbering system used in this question paper. 4. Leave ONE line between two sub questions, e.g. between QUESTION 2.1 and QUESTION 2.2. 5. You may use a non-programmable calculator. 6. You are advised to use the attached DATA SHEETS. 7. Round off your FINAL numerical answers to a minimum of TWO decimal places. 8. Give brief motivations, discussions etc. where required. 9. Write neatly and legibly. Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 3 NW/September 2019 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 number (1.1- 1.10) in the ANSWER BOOK, e.g. 1.2. B. 1.1 Which of the following is the general formula for alkynes? A CnH2n B CnH2n + 2 C CnH2n – 2 D CnH2nO (2) 1.2 Which ONE of the following hydrocarbons is saturated? A C3H6 B C4H6 C C3H8 D C4H8 (2) 1.3 To which of the following homologous series does the compound below belong? A Alkane B Esters C Haloalkanes D Carboxylic acid (2) 1.4 Which monomer is used to produce polythene? A Chloroethene B Bromoethene C Ethane D Ethene (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 4 NW/September 2019 NSC 1.5 A certain standard electrochemical cell can be represented as follows: Zn + Cu2+ → Zn2+ + Cu Which ONE of the following will serve as the reducing agent? A Cu2+ B Zn2+ C Cu D Zn (2) 1.6 Which statement is true for an electrochemical cell? A Oxidation occurs at the anode. B Reduction occurs at the anode. C Oxidation occurs at both the cathode and the anode. D Reduction occurs at both the cathode and the anode. (2) 1.7 What will be the independent variable in an experiment to determine the path of a ray of light through a glass prism at different angles of incidence? A Angle of reflection B Emergent angle C Angle of incidence D Angle of refraction (2) 1.8 What is the angle of incidence, where the angle of refraction is 90° and the light travel from an optically denser medium to an optically less dense medium? A Emergent angle B Critical angle C Angle of reflection D Angle of refraction (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 5 NW/September 2019 NSC 1.9 The frequeny of electromagnetic wave is 2 GHz and its wavelength is 1 cm. The speed of the wave be equal to: A 2× 106 × 0,01 B 2× 10-9 × 0,01 C 2× 10-6 × 0,01 D 2× 109 × 0,01 (2) 1.10 Which electromagnetic radiation is used by soldiers in night vision devices to see objects at night? A Infrared light B Ultraviolet light C Gamma rays D Visible spectrum (2) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 6 NW/September 2019 NSC QUESTION 2 2.1 Define the following terms: 2.1.1 Homologous series (2) 2.1.2 Hydrocarbon (2) 2.2 Consider the following molecules A and B and answer the questions below: Write down the: 2.2.1 Structural formula of the functional group of compound B. (2) 2.2.2 Molecular formula of compound A. (1) 2.2.3 IUPAC name of compound B. (2) 2.2.4 Letter representing an unsaturated compound. (1) 2.2.5 Homologous series of compound A. (1) 2.3 Consider the following structural isomers: C D 2.3.1 Define the term structural isomer. (2) 2.3.2 What type of isomers are compounds C and D. (1) 2.3.3 What is the NAME of the functional group of compound D? (1) Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 7 NW/September 2019 NSC 2.3.4 Write down the general formula of these compounds. (1) 2.4 Draw the structural formula of 2–bromo –3–methylbutane. (3) [19] QUESTION 3 The grade 12 learners conducted an experiment to compare the boiling points of organic compounds (A–D) . The results are recorded in the table below: MOLECULAR MASS BOILING POINT COMPOUNDS (g•mol-1) (℃ ) A Propanoic acid 74 141 B Propanol 60 97 C Propane 44 – 42 D Propene 42 – 48 3.1 Define the term boiling point. (2) 3.2 The boiling point of compound C is much lower than that of compound A. Name the type of intermolecular forces that are responsible for this difference in: 3.2.1 Compound A (1) 3.2.2 Compound C (1) 3.3. Is compound C a gas or liquid at room temperature? (1) 3.4 Consider the boiling points of compound A and D. Give a reason for this difference in the boiling point by referring to the TYPE, STRENGTH OF INTERMOLECULAR FORCES AND THE ENERGY NEEDED. (3) 3.5 Which compound has the highest vapour pressure? (1) 3.6 Explain the answer in QUESTION 3.5. (2) 3.7 Explain the trend in the boiling points of these organic compounds. (2) [13] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 8 NW/September 2019 NSC QUESTION 4 The flow diagram below shows some of the reactions of butene. 4.1 What type of addition reaction is represented by EACH of the following letters? 4.1.1 C (1) 4.1.2 A (1) 4.1.3 B (1) 4.2 C4H10 is used in household gas stoves. The gas is ignited in sufficient oxygen. Write down a balanced molecular equation for the reaction that will occur. (3) 4.3 Use a STRUCTURAL FORMULAE to write down a balanced chemical equation for reaction B. (5) 4.4 A polymer is given below: 4.4.1 Define the term plastic. (2) 4.4.2 Write down the NAME of the polymer represented above. (1) [14] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 9 NW/September 2019 NSC QUESTION 5 Electrolytic cell used to electroplate a metal (spoon) with silver is shown below. 5.1 Explain what electroplating means. (2) 5.2 Write down the energy conversion taking place in this cell. (2) 5.3 Is this cell spontaneous or non–spontaneous? (1) 5.4 Explain your answer in QUESTION 5.3. (2) 5.5 Write down the NAME or FORMULA of the oxidising agent. (1) 5.6 What is the function of the battery in this cell? (2) 5.7 Give the NAME or FORMULA of the electrolyte that should be used in this process. (1) 5.8 Write TWO observations that can be made during this process. (2) [13] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 10 NW/September 2019 NSC QUESTION 6 The diagram below represents the setup of a galvanic cell. 6.1 Define a galvanic cell. (2) 6.2 Write down TWO standard conditions applicable to this cell. (2) 6.3 In which direction will the electrons flow in the external circuit? Write down from Zn ELECTRODE TO Cu ELECTRODE or Cu ELECTRODE TO Zn ELECTRODE. (1) 6.4 What type of reaction is this? (ENDOTHERMIC or EXOTHERMIC). Explain your answer. (2) 6.5 Define the term reduction. (2) 6.6 Write down the: 6.6.1 Half reaction that takes place at the anode. (2) 6.6.2 Cell notation for this cell. (3) 6.7 Calculate the emf of this cell. (4) 6.8 Write TWO functions of a salt bridge. (2) 6.9 Why would KNO3 be a suitable electrolyte that can be used in the salt bridge? (2) [22] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 11 NW/September 2019 NSC QUESTION 7 7.1 State the law of reflection. (2) 7.2 Write down FOUR properties of an image in a flat mirror. (4) 7.3 Write ONE word for the following: 7.3.1 The imaginary line perpendicular to the surface of an object. (2) 7.3.2 When the light is incident on an irregular surface and is reflected in all directions. (2) 7.4 When white light falls into a triangular prism, the following phenomenon is observed: White light Glass prism 7.4.1 Define dispersion. (2) 7.4.2 Which colour of light is refracted the least? (1) 7.4.3 Explain the answer to QUESTION 7.4.2 in terms of wavelength. (2) 7.4.4 Which colour of light will have the shortest wavelength? (1) [16] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 12 NW/September 2019 NSC QUESTION 8 8.1. Study the diagram of refraction of light in water and answer the following questions. 8.1.1 Define the term refraction. (2) 8.1.2. Redraw the DIAGRAM and label it including the TWO media used. (7) 8.1.3 What happens to the speed of light when it enters water? (1) 8.2 Give TWO conditions of total internal reflection. (4) 8.3 Name TWO application of total internal reflection. (2) 8.4 An object 30 mm high is placed 50 mm from a convex lens of focal length 15 mm. Draw a ray diagram accurately to scale showing the formation of the image. (5) 8.5 Name TWO visual defects that are corrected by spectacles. (2) [23] Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 13 NW/September 2019 NSC QUESTION 9 9.1 Define electromagnetic wave. (2) 9.2 Electromagnetic waves are divided into SEVEN categories depending on their wavelength and frequency. Name them according to their decreasing wavelength. (2) 9.3 Which radiation is used? 9.3.1 For treatment of skin disorders. (1) 9.3.2 For communication and television. (1) 9.4 Calculate the frequency of the light, if a photon has 3, 44 × 10-23 J of energy. (4) [10] TOTAL: 150 Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 14 NW/September 2019 NSC DATA FOR TECHNICAL SCIENCES GRADE 12 PAPER 2 TABLE 1: PHYSICAL CONSTANTS NAME SYMBOL VALUE 5 Standard pressure 1,01 x 10 Pa Standard temperature 273 K/ 0° C 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 or TABLE 3: FORMULAE ° ° ° or ° ° ° or ° ° ° Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 15 NW/September 2019 NSC TABLE 4A: STANDARD REDUCTION POTENTIALS Half-reactions (V) F2(g) + 2e− ⇌ 2F− + 2,87 Co3+ + e− ⇌ Co2+ + 1,81 H2O2 + 2H+ +2e− ⇌ 2H2O +1,77 MnO4 –+ 8H+ +5e− ⇌ Mn2+ + 4H2O + 1,51 Cℓ2(g) + 2e− ⇌ 2Cℓ− + 1,36 Cr2O7 + 14H++6e− 2– ⇌ 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 NO3 + 4H+ + 3e− – ⇌ NO(g) + 2H2O + 0,96 Hg2+ + 2e− ⇌ Hg(ℓ) + 0,85 Ag+ + e – ⇌ Ag + 0,80 NO3 + 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 Increasing reducing ability 2H2O + O2 + 4e− ⇌ 4OH− + 0,40 Increasing oxidising ability Cu2+ + 2e− ⇌ Cu + 0,34 SO4 + 4H+ + 2e− 2– ⇌ 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 Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 16 NW/September 2019 NSC TABLE 4B: STANDARD REDUCTION POTENTIALS Half-reactions (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 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 Increasing oxidising ability Sn2+ + 2e- ⇌ Sn - 0,14 Increasing reducing ability 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 – SO4 + 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 – NO3 + 2H+ + e- ⇌ NO2(g) + H2O + 0,80 Ag+ + e- ⇌ Ag + 0,80 Hg2+ + 2e- ⇌ Hg(ℓ) + 0,85 – NO3 + 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 Cr2O7 –+ 14H+ +6e- ⇌ 2Cr3+ + 7H2O + 1,33 Cℓ2(g) + 2e- ⇌ 2Cℓ- + 1,36 – MnO4 + 8H+ + 5e- ⇌ Mn2+ + 4H2O + 1,51 H2O2 + 2H+ +2 e- ⇌ 2H2O +1,77 Co3+ + e- ⇌ Co2+ + 1,81 F2(g) + 2e- ⇌ 2F- + 2,87 Copyright reserved Please turn over

Downloaded from hlayiso.com Technical Sciences/P2 17 NW/September 2019 NSC TABLE 5: THE PERIODIC TABLE OF ELEMENTS Copyright reserved