Technical Sciences Grade 12 P2 Gauteng Mock 2025 Memo (Eng)

PREPARATORY EXAMINATION 2025 MARKING GUIDELINES TECHNICAL SCIENCES (PAPER 2) (11102) 7 pages

11102/25 QUESTION 1 1.1 B ✓✓ (2) 1.2 C ✓✓ (2) 1.3 D ✓✓ (2) 1.4 B ✓✓ (2) 1.5 D ✓✓ (2) [10] QUESTION 2 2.1 An atom or a group of atoms that determine the chemistry of a molecule. ✓✓ (0 or 2 marks) OR An atom or a group of atoms that determine(s) the physical and chemical properties of a group of organic compounds. (2) 2.2 2.2.1 E✓ (1) 2.2.2 Halo alkane/Alkyl halide ✓ (1) 2.2.3 Formyl ✓ (1) 2.2.4 Ethyl ethanoate Marking criteria • Ethyl ✓ • Ethanoate ✓ (2) 2

11102/25 2.3 2.3.1 Marking criteria • Functional group ✓ • Whole structure correct ✓ Note: • Any hydrogen bond or atom missing MAX 1 mark (2) 2.3.2 𝐶𝐻2 𝐵𝑟𝐶𝐻(𝐶𝐻3 )𝐶𝐻3 ✓ (The bracket must be present) (1) 2.3.3 𝐶6 𝐻12 𝑂 ✓ (1) 2.4 Organic molecules with the same molecular formula but different structural formulae ✓✓ (0 or 2 marks) (2) 2.5 2.5.1 Positional ✓ (1) 2.5.2 Functional ✓ (1) [15] QUESTION 3 3.1 The temperature at which the vapour pressure equals atmospheric pressure ✓✓ (0 or 2 marks) Marking criteria • If the learner referred to POINT, then 0 marks (2) 3.2 Stop watch/wall clock/wrist watch ✓ (any applicable answer) (1) 3.3 A ✓ (1) 3

11102/25 3.4 Negative marking from 3.3 • Propane has only weak London/dispersion/induced dipole forces ✓ • Propan-2-ol has weak London/dispersion/induced dipole forces and strong Hydrogen bonds ✓ • More energy is needed to overcome the intermolecular forces of propan-2-ol thus it has a higher boiling point. ✓ OR • Propane has only weak London/dispersion/induced dipole forces • Propan-2-ol has weak London/dispersion/induced dipole forces and strong Hydrogen bonds • Less energy is needed to overcome the intermolecular forces of propane thus it has a lower boiling point and propan-2-ol the higher boiling point Marking criteria • Identify the intermolecular forces of propane and propan-2-ol • Compare the strength of the intermolecular forces (Hydrogen bonds are stronger than London forces) • Refer to how much energy is needed to OVERCOME the intermolecular forces (3) 3.5 • Viscosity has to do with the resistance of a fluid ✓ • Because propan-2-ol has the strongest intermolecular forces, it means it has a higher viscosity. ✓ • This means it has a bigger resistance to flow thus taking longer to form droplets to pour ✓ OR • Viscosity has to do with the resistance of a fluid • Because propane has the weakest intermolecular forces, it means it has a lower viscosity. • This means it has a smaller resistance to flow thus forming droplets quicker to pour OR • Viscosity has to do with the resistance of a fluid • It is proportional to the boiling point and since propan-2-ol has the highest boiling point, it means it has a higher viscosity. • This means it has a bigger resistance to flow thus taking longer to form droplets to pour OR • Viscosity has to do with the resistance of a fluid • It is proportional to the boiling point and since propane has the lowest boiling point, it means it has a lower viscosity. • This means it has a smaller resistance to flow thus forming droplets quicker to pour (3) [10] 4

11102/25 QUESTION 4 4.1 4.1.1 Addition / Hydrogenation ✓ (1) 4.1.2 𝐻2 ✓ (It must be the MOLECULAR FORMULA and not the name). (1) 4.1.3 2𝐶2 𝐻6 + 7𝑂2 → 4𝐶𝑂2 + 6𝐻2 𝑂 + (𝐸) Marking criteria • C2H6 + O2 ✓ • CO2 + H2O + (E) ✓ • Balancing ✓ (3) 4.2 4.2.1 Chloroethane / 1-chloroethane Marking criteria • Chloro ✓ • Ethane ✓ (2) 4.2.2 No water must be present during the reaction ✓ (1) 4.3 4.3.1 Water ✓ (It must be the NAME and not the molecular formula). (1) 4.3.2 Addition / Hydration ✓ (1) 4.4 4.4.1 A chemical reaction in which monomer molecules joins to form a polymer. ✓✓ (0 or 2 marks) (2) 4.4.2 Unsaturated ✓ (1) 4.4.3 • Plastic bottles ✓ • Plastic bags • Plastic toys • Plastic lids • Plastic pipes • Insulation tape (any applicable example) (1) 4.5 4.5.1 ✓ Marking criteria • Must be drawn with the arrow (anode) pointing from left to right and the line (cathode) on the right (1) 4.5.2 Forward ✓ (1) 4.5.3 • Converts AC current to DC current for electronic devices to protect them from damage ✓ • Regulates voltage in circuits by ensuring constant voltage (any applicable reason) (1) [17] 5

11102/25 QUESTION 5 5.1 It is the loss in electrons ✓✓ (0 or 2 marks) OR It is an increase in oxidation number. (2) 5.2 5.2.1 Gas bubbles are formed ✓ Marking criteria • MUST refer to the bubbles and not chlorine gas is forming or chlorine is smelled) (1) 5.2.2 2𝐶𝑙 − (𝑎𝑞) → 𝐶𝑙2(𝑔) + 2𝑒 − ✓✓ Marking criteria • 𝐶𝑙2 + 2𝑒 − ← 2𝐶𝑙 − (2/2) • 2𝐶𝑙 − ⇌ 𝐶𝑙2 + 2𝑒 − (1/2) • 2𝐶𝑙 − ← 𝐶𝑙2 + 2𝑒 − (0/2) • 2𝐶𝑙 − + 2𝑒 − ⇌ 𝐶𝑙2 (0/2) NOTE: • Do not penalise if the phases are not included or an electron charge is omitted. (2) 5.3 5.3.1 Negative ✓ (1) 5.3.2 • Copper wire ✓ • Coins • Jewellery (any acceptable example) (1) 5.4 • The switch is open meaning there is a break in the circuit so no current can flow. ✓ • The key will not be able to undergo reduction (because it can’t be charged negatively) ✓ • It will not be able to attract the copper ions (cations) to create a solid copper coating on it. ✓ 5.5 Electroplating ✓ (3) 5.6 Cathode ✓ (1) 5.7 • Prevents it from rusting ✓ • To increase its value (any applicable reason) (1) [13] 6

11102/25 QUESTION 6 6.1 It is an electrochemical cell that converts chemical energy into electrical energy ✓✓ (0 or 2 marks) (2) 6.2 Salt bridge ✓ (1) 6.3 Temperature = 25 0C / 298 K✓ (1) 6.4 𝐸 𝜃 𝑐𝑒𝑙𝑙 = 𝐸 𝜃 𝑐𝑎𝑡ℎ𝑜𝑑𝑒 − 𝐸 𝜃 𝑎𝑛𝑜𝑑𝑒 ✓ 2,7 ✓ = 0,34 ✓ – 𝐸 𝜃 𝑎𝑛𝑜𝑑𝑒 𝐸 𝜃 𝑎𝑛𝑜𝑑𝑒 = -2,36 V ✓ ∴ Mg / Magnesium ✓ Marking criteria • No unit for the emf -1 mark • If there is no 𝜃 or if any other formula using unconventional abbreviations, e.g., Ecell = EOA – ERA, followed by correct substitutions then -1 mark Note: • Accept any other formula from the data sheet • No marks if ONLY the formula is written and no substitution is made (5) 6.5 Right to left ✓ (1) [10] TOTAL: 75 7