Physical Sciences Grade 12 P2 Gauteng June 2025 QP (Eng)

JUNE EXAMINATION GRADE 12 2025 PHYSICAL SCIENCES: CHEMISTRY (PAPER 2) TIME: 3 hours MARKS: 150 16 pages + 2 data sheets Please turn over

PHYSICAL SCIENCES: CHEMISTRY 2 (PAPER 2) GR12 0625 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 the ANSWER BOOK. 3. Number the answers correctly according to the numbering system used in the question paper. 4. Leave ONE line open between two subquestions, e.g., between QUESTION 2.1 and QUESTION 2.2. 5. You may use a non-programmable calculator. 6. You may use appropriate mathematical instruments. 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 discussions, et cetera where required. 10. You are advised to use the attached DATA SHEETS. 11. Write neatly and legibly. Please turn over

PHYSICAL SCIENCES: CHEMISTRY 3 (PAPER 2) GR12 0625 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various options are provided as possible answers to the following questions. Each question has only ONE correct answer. 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 of the following represents a SATURATED hydrocarbon? A C2H4 B C3H6 C C3H8 D C4H8 (2) 1.2 Which of the following pairs of reactants can be used to prepare the ester called ethyl propanoate in the laboratory? A Ethane and propanoic acid B Propanol and ethanoic acid C Ethanol and propanoic acid D Ethene and propanol (2) 1.3 Consider the reaction represented by the equation below: CH3CHCH2 + HBr → CH3CHBrCH3 What type of reaction is represented above? A Halogenation B Substitution C Hydrogenation D Hydrohalogenation (2) 1.4 Consider the following compound: CH3CH(C)CH2C(CH3)3 The IUPAC name of this compound is: A 2-chloro-4,4-dimethylpentane B 2,2-dimethyl-4-chloropentane C 4,4-dimethyl-2-chloropentane D 4-chloro-2,2-dimethylpentane (2) Please turn over

PHYSICAL SCIENCES: CHEMISTRY 4 (PAPER 2) GR12 0625 1.5 Two learners want to investigate the factors affecting the rate of reaction between magnesium (Mg) and hydrochloric acid (HC). The concentration of the acid remains the same. gas syringe test tube containing magnesium excess dilute hydrochloric acid Which of the following changes to the experiment will produce the fastest rate of reaction? A Powdered magnesium with hydrochloric acid at room temperature B Powdered magnesium with hydrochloric acid at a higher temperature C Magnesium ribbon with hydrochloric acid at a higher temperature D Magnesium ribbon with hydrochloric acid at room temperature (2) Please turn over

PHYSICAL SCIENCES: CHEMISTRY 5 (PAPER 2) GR12 0625 1.6 Consider the energy profile graph for a REVERSIBLE REACTION shown below. Potential energy (kJ·mol ) -1 products reactants Course of reaction The following statements are given: (i) a – c represents the activation energy for the reverse reaction. (ii) ∆H for the reverse reaction is a – b. (iii) A catalyst lowers the activation energy for both forward and reverse reactions. Identify the CORRECT statement(s). A (ii) and (iii) only B (iii) only C (i), (ii) and (iii) D (i) only (2) 1.7 The reaction of an acid-base indicator (In-) represented as HIn(aq), with H2O() reaches equilibrium according to the following balanced equation: HIn(aq) + H2O() ⇌ H3O+(aq) + In-(aq) ΔH < 0 Red Yellow At equilibrium, the colour of the solution is red. Which of the following will change the colour of the solution from red to yellow? A Increasing the concentration of H₃O⁺ ions B Increasing the temperature of the solution C Adding a base D Adding an acid (2) Please turn over

PHYSICAL SCIENCES: CHEMISTRY 6 (PAPER 2) GR12 0625 1.8 The expression for the equilibrium constant (KC) of a hypothetical reaction is given as follows: [PQ3 ]2 KC = [Q2 ]3 Which of the following equations for a reaction at equilibrium matches the above expression? A P2(g) + 3Q2(g) ⇌ 2PQ3(aq) B 2PQ3() ⇌ P2(g) + 3Q2(g) C 2PQ3(aq) ⇌ P2(g) + 3Q2(g) D P2(s) + 3Q2(g) ⇌ 2PQ3(g) (2) 1.9 Which statement best describes the difference between the endpoint and the equivalence point in a titration? A The endpoint occurs when the acid or base has completely reacted with each other, while the equivalence point is when the indicator changes colour. B The equivalence point occurs when the acid or base has completely reacted with each other, while the endpoint is when the indicator changes colour. C The endpoint and equivalence point occur at different times and have no connection in a titration. D The equivalence point and endpoint are always exactly the same in every titration. (2) Please turn over

PHYSICAL SCIENCES: CHEMISTRY 7 (PAPER 2) GR12 0625 1.10 A titration experiment was conducted using a sodium hydroxide (NaOH) standard solution of concentration 0,1 mol.dm-3 and hydrochloric acid (HC) of unknown concentration. In each titration, a volume of 20 cm3 of NaOH was used. The readings from the burette are given in the table below. Volume of HC Titration (in cm3) 1 26,66 2 26,50 3 26,60 What is the concentration, in mol.dm-3, of the HC required to neutralise the NaOH? A 0,0752 B 0,0750 C 0,0754 D 0,0755 (2) [20] Please turn over

PHYSICAL SCIENCES: CHEMISTRY 8 (PAPER 2) GR12 0625 QUESTION 2 (Start on a new page.) The letters A to H in the table below represent organic compounds. A C5H12 B C4H8O2 C Ethyl butanoate D CH3CHCHCH2CH3 H H H H H O E Butan-1-ol F H C C C C C C O H H H H H H H H H H G H H C C C C H H OH H H 2.1 Consider compound H. Is this a PRIMARY, SECONDARY or TERTIARY alcohol? Explain the answer. (3) 2.2 Write down the letter that represents each of the following: 2.2.1 A ketone (1) 2.2.2 A MOLECULAR FORMULA of a hydrocarbon (1) 2.2.3 A reactant in the preparation of compound C (1) 2.3 Write down the STRUCTURAL formula of: 2.3.1 Compound D (2) 2.3.2 The FUNCTIONAL group of compound F (2) 2.3.3 The FUNCTIONAL isomer of compound G with a prefix of 4-methyl (2) 2.4 Write down the IUPAC name of: 2.4.1 Compound D (2) 2.4.2 Compound G (3) 2.5 Consider compounds E and H. 2.5.1 Identify the type of isomer. (1) 2.5.2 Define this type of isomer. (2) Please turn over

PHYSICAL SCIENCES: CHEMISTRY 9 (PAPER 2) GR12 0625 2.6 Consider compound C. 2.6.1 To which homologous series does compound C belong? (1) 2.6.2 Give the NAME of the catalyst required in the preparation of compound C. (1) 2.6.3 Draw the STRUCTURAL FORMULA of compound C. (3) [25] QUESTION 3 (Start on a new page.) The factors that affect the vapour pressure of different organic compounds are investigated. The table below shows the vapour pressure of five organic compounds, represented by the letters A – E. MOLECULAR VAPOUR ORGANIC MASS PRESSURE COMPOUND (g.mol-1) (kPa) at 25 °C A Propane 44 953,25 B Butane 58 242,63 C Ethyl methanoate 74 32,38 D Alcohol 59 2,80 E Propanoic acid 74 0,47 3.1 Define the term vapour pressure. (2) 3.2 Write down the homologous series to which compounds A and B belong. (1) 3.3 Explain the decrease in vapour pressure from compound A to compound B, as indicated in the table. (3) 3.4 Compounds C and E are functional isomers. 3.4.1 Define molecular formula. (2) 3.4.2 Which compound will have a higher boiling point? (1) 3.4.3 Explain the answer to QUESTION 3.4.2. (4) 3.5 The percentage composition of some of the elements in compound D is given as 61% carbon and 11,86% hydrogen. Determine, with calculations, the empirical formula of compound D. (4) 3.6 Write a balanced equation using molecular formulae for a complete combustion of compound A. (3) [20] Please turn over

PHYSICAL SCIENCES: CHEMISTRY 10 (PAPER 2) GR12 0625 QUESTION 4 (Start on a new page.) The flow diagram below shows how an alkene can be used to prepare other organic compounds. The letters J to N represent various organic reactions. Compound Q K L HBr N alcohol butane CH2=CH-CH2-CH3 (major product) J HCl M Compound R Compound S (major product) + (minor product) 4.1 Is an alkene a SATURATED or UNSATURATED hydrocarbon? Explain the answer. (3) 4.2 Write down the type of reaction represented by: 4.2.1 J (1) 4.2.2 K (1) 4.2.3 M (1) 4.3 Write down the STRUCTURAL FORMULA of compound R. (2) 4.4 For reaction N, write down: 4.4.1 The type of addition reaction (1) 4.4.2 Two reaction conditions (2) 4.4.3 The IUPAC name of the alcohol that forms (2) 4.5 Write down the IUPAC name of an isomer of butane. (2) 4.6 Use STRUCTURAL formulae to write down a balanced equation for reaction L. (5) [20] Please turn over

PHYSICAL SCIENCES: CHEMISTRY 11 (PAPER 2) GR12 0625 QUESTION 5 (Start on a new page.) Three different experiments are performed using the reaction between magnesium carbonate and hydrochloric acid: MgCO3(s) + 2HC(aq) → MgC2(aq) + H2O() + CO2(g) EXPERIMENT I In this experiment, magnesium carbonate reacts with EXCESS hydrochloric acid in a closed container at 23 oC. The reaction is monitored by measuring the volume of carbon dioxide gas produced over time. The molar gas volume at 23 oC is 24 dm3. The data collected is shown in the table below. TIME (s) VOLUME OF CO2 (cm3) 0 0 10 180 20 300 30 410 40 470 50 500 60 500 5.1 Define the term reaction rate. (2) 5.2 Use the collision theory to explain the effect on the reaction rate as time progresses. (4) 5.3 Calculate the reaction rate for the production of CO2(g) during the first 20 seconds, in dm3.s-1. (3) 5.4 Calculate the mass of MgCO3 required for this experiment. (4) Please turn over

PHYSICAL SCIENCES: CHEMISTRY 12 (PAPER 2) GR12 0625 EXPERIMENT II 5.5 Experiment I is repeated, but this time at 30 °C. The following Maxwell-Boltzmann distribution curve was produced. Number of molecules Kinetic energy 5.5.1 Which graph, A or B, best represents Experiment II? (1) 5.5.2 Explain the answer to QUESTION 5.5.1. (2) 5.5.3 If a catalyst was added, would the line representing the activation energy (Ea) be drawn to the LEFT or the RIGHT of the current line? (1) Please turn over

PHYSICAL SCIENCES: CHEMISTRY 13 (PAPER 2) GR12 0625 EXPERIMENT III 5.6 Experiment I is repeated, but a catalyst is added, and the following graph is obtained. A CATALYSED CHEMICAL REACTION Progress of the reaction 5.6.1 Is the reaction EXOTHERMIC or ENDOTHERMIC? (1) 5.6.2 Which letter represents the activated complex? (1) 5.6.3 Give the value of the activation energy for the forward catalysed reaction. (1) [20] Please turn over

PHYSICAL SCIENCES: CHEMISTRY 14 (PAPER 2) GR12 0625 QUESTION 6 (Start on a new page.) The reaction between carbon disulfide CS2(g) and chlorine gas Cℓ2(g) reaches chemical equilibrium in a closed container at constant temperature. The products that form are carbon tetrachloride CCℓ4(g) and sulphur dichloride S2Cℓ2(g). The balanced equation for this reaction is given below: CS2(g) + 3Cℓ2(g) ⇌ CCℓ4(g) + S2Cℓ2(g) ∆H < 0 Initially, an unknown quantity of CS2(g) and 5 moles of Cℓ2 are placed in a 2 dm3 container and allowed to reach equilibrium. The equilibrium mixture contains 0,8 mol of CCℓ4. The equilibrium constant, Kc, for this reaction is 0,36. 6.1 State Le Chatelier's principle. (2) 6.2 Calculate the initial number of moles of CS2(g) required. (8) 6.3 How will each of the following changes affect the yield of S2Cℓ2(g) at equilibrium? Write INCREASE, DECREASE, or REMAIN THE SAME and give a reason in terms of the reaction which is favoured. 6.3.1 Carbon tetrachloride is removed from the system (2) 6.3.2 The volume of the container is increased (2) Please turn over

PHYSICAL SCIENCES: CHEMISTRY 15 (PAPER 2) GR12 0625 6.4 The graph below shows the changes in the rate of the reaction after further changes were made to the equilibrium mixture above. Forward reaction: Reverse reaction: Rate (mol·s ) -1 Time (min) 6.4.1 The equilibrium was disturbed at 5 minutes due to a change in the concentration of CS2. Was this concentration INCREASED or DECREASED? (1) 6.4.2 At 15 minutes the temperature was changed. Use Le Chatelier’s principle to determine whether the temperature has INCREASED or DECREASED. Explain the answer. (4) 6.4.3 At what time does the system reach equilibrium after the temperature change? (1) [20] Please turn over

PHYSICAL SCIENCES: CHEMISTRY 16 (PAPER 2) GR12 0625 QUESTION 7 (Start on a new page.) Oxalic acid (H2C2O4) is an organic diprotic acid commonly found in plants such as spinach. It is used in various industrial and laboratory applications, including cleaning, bleaching, and as a standard solution in acid-base titrations. When oxalic acid ionises in water, it follows the steps given below: STEP 1: H2C2O4(aq) + H2O() → HC2O4-(aq) + H3O+(aq) STEP 2: HC2O4⁻(aq) + H2O() → C2O4²⁻(aq) + H3O⁺(aq) 7.1 Define a weak acid. (2) 7.2 Identify the acid-base conjugate pair in STEP 1. (2) 7.3 Give a reason why oxalic acid is referred to as a diprotic acid. (1) 7.4 The oxalate ion (HC2O4⁻) can act as an ampholyte. Give a reason for this statement. (1) 7.5 In a volumetric flask 2,25 g of oxalic acid is added to water to make up a standard solution to 250 cm3. 7.5.1 Calculate the concentration of the oxalic acid solution. (3) 7.5.2 25 cm3 of the oxalic acid solution is titrated against sodium hydroxide. The average volume of NaOH required for neutralisation is 28,60 cm3. H2C2O4(aq) + 2NaOH(aq) → Na2C2O4(aq) + 2H2O() Calculate the concentration of the sodium hydroxide. (4) 7.5.3 Explain why phenolphthalein would be a suitable indicator for this reaction. (2) 7.6 The reaction between EXCESS magnesium hydroxide (Mg(OH)₂), a slightly soluble base, and nitric acid (HNO3), occurs in aqueous solution, where it produces magnesium nitrate (Mg(NO3)2), a soluble salt and water, according to the following balanced equation below. Mg(OH)₂(aq) + 2HNO₃(aq) → Mg(NO₃)₂(aq) + 2H₂O(). 0,05 dm3 of the Mg(OH)₂ solution has a concentration 0,115 mol.dm-3 and is added to 0,025 dm3 of a 0,095 mol.dm-3 HNO₃ solution. Calculate the pH of the FINAL solution. (10) [25] TOTAL: 150 END

PHYSICAL SCIENCES: CHEMISTRY 1 (PAPER 2) GR12 0624 DATA FOR PHYSICAL SCIENCES GRADE 12 PAPER 2 (CHEMISTRY) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 12 VRAESTEL 2 (CHEMIE) TABLE 1: PHYSICAL CONSTANTS/TABEL 1: FISIESE KONSTANTES NAME/NAAM SYMBOL/SIMBOOL VALUE/WAARDE Standard pressure p 1,013 x 105 Pa Standaarddruk Molar gas volume at STP Vm 22,4 dm3∙mol-1 Molêre gasvolume by STD Standard temperature T 273 K Standaardtemperatuur Charge on electron e -1,6 x 10-19 C Lading op elektron Avogadro’s constant NA 6,02 x 1023 mol-1 Avogadro-konstante TABLE 2: FORMULAE/TABEL 2: FORMULES m N n n M NA n m V c OR/OF c n V MV VM c a Va na  pH = - log[H3O+] cb Vb nb Kw = [H3O+][OH-] = 1 x 10-14 at/by 298 K E θcell  E θcathode  E θanode / E sel  Ekatode    E anode or/of  Ecell  E θ reduction E θ oxidation/ Esel  Ereduksie    Eoksidasie or/of    E cell  E oxidi sin g agent  E reducing agent / E sel  E oksideermiddel  E reduseermiddel θ θ θ

PHYSICAL SCIENCES: CHEMISTRY 2 (PAPER 2) GR12 0625 TABLE 3: THE PERIODIC TABLE OF ELEMENTS/TABEL 3: 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/ KEY/SLEUTEL Atoomgetal 1 2 2,1 H He 1 29 4 Electronegativity/ Symbol/ 3 4 Elektronegatiwiteit 1,9 Cu Simbool 5 6 7 8 9 10 1,0 Li 1,5 Be 2,0 B 2,5 C 3,0 N 3,5 O 4,0 F Ne 63,5 7 9 11 12 14 16 19 20 11 12 13 14 15 16 17 18 Na Mg Approximate relative atomic mass/ Aℓ Si P S Cℓ Ar 0,9 1,2 Benaderde relatiewe atoommassa 1,5 1,8 2,1 2,5 3,0 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 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tℓ Pb Bi Po At Rn 0,7 0,9 1,6 1,8 1,8 1,9 2,0 2,5 133 137 139 179 181 184 186 190 192 195 197 201 204 207 209 87 88 89 0,7 Fr 0,9 Ra Ac 226 58 59 60 61 62 63 64 65 66 67 68 69 70 71 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