Physical Sciences Grade 12 P2 Eastern Cape June 2022 QP

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 JUNE 2022 PHYSICAL SCIENCES: CHEMISTRY P2 MARKS: 150 TIME: 3 hours This question paper consists of 20 pages, including 2 data sheets.

Downloaded from hlayiso.com 2 PHYSICAL SCIENCES P2 (EC/JUNE 2022) INSTRUCTIONS AND INFORMATION 1. Write your name and surname in the appropriate spaces on the ANSWER BOOK. 2. This question paper consists of SEVEN 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. You may use a non-programmable calculator. 7. You may use appropriate mathematical instruments. 8. You are advised to use the attached DATA SHEETS. 9. Show ALL formulae and substitutions in ALL calculations. 10. Round off your FINAL numerical answers to a minimum of TWO decimal places. 11. Give brief motivations, discussions, et cetera where required. 12. Write neatly and legibly. Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 3 QUESTION 1: MULTIPLE-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, for example. 1.11 E. 1.1 Which ONE of the following is the general formula of alkenes? A CnH2n B C2H2n+2 C CnH2n-2 D CnH2n+1 (2) 1.2 When the carbonyl group is located at the end of an organic molecule, to which ONE of the given homologous series does the molecule belong? A Alcohol B Aldehyde C Ketone D Haloalkane (2) 1.3 Which ONE of the following compounds has the HIGHEST boiling point? A Octane B 2-methylheptane C 2,3-dimethylhexane D 2,2,3-trimethylpentane (2) 1.4 Which ONE of the following changes will INCREASE the average kinetic energy of particles? A Catalyst B Decrease in temperature C Increase in temperature D Increase in surface area (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 4 PHYSICAL SCIENCES P2 (EC/JUNE 2022) 1.5 Consider the organic reaction below in which compound P is the MAJOR organic product. CH3CH(CH3)CH2CH = CH2 + H2O → compound P The correct IUPAC name of the major organic product P is … A 4-methylpentan-1-ol. B 4-methylpentan-2-ol. C 2-methylpentan-1-ol. D 2-methylpentan-2-ol. (2) 1.6 Consider the potential energy diagram for the following hypothetical reversible reaction. Q ⇌ P Potential energy (kJ·mol-1) Z Y P X Q time Which ONE of the following is the CORRECT interpretation of the information displayed in the graph? ∆H forward reaction ∆H reverse reaction A Y–Z Z–Y B Z–Y Y–Z C X–Y Y–X D Y–X X–Y (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 5 1.7 Consider the following reaction at equilibrium at temperature T. NO2(g) ⇌ N2O4(g) ∆H < 0 The temperature of the reaction mixture is increased. Which ONE of the following is CORRECT about the RATE OF THE FORWARD REACTION and the YIELD of N2O4 immediately after the temperature is increased? Rate of the forward reaction Yield of N2O4 A Decreases Increases B Increases Decreases C Increases Increases D Decreases Decreases (2) 1.8 Which ONE of the following graphs CORRECTLY describe the relationship between the [H3O+] and pH? A B pH pH [H3O+] [H3O+] C D pH pH [H3O+] [H3O+] (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 6 PHYSICAL SCIENCES P2 (EC/JUNE 2022) 1.9 Consider the acid-base reaction below. H2PO4 + OH ⇌ H2O + Q The correct formula for substance Q is … A H3PO4. B HPO42-. C PO43-. D H3O+. (2) 1.10 The following circuit is used to test the conductivity of acids, HA and HB, at 25 °C. Both acids have a concentration of 1 mol·dm-3. A carbon rod carbon rod acid The learners’ results are shown in the table below. ACID AMMETER READING (A) HA 0,8 HB 1,5 Learners write the following statements as their conclusions down: I. HA is a stronger acid than HB II. pH of HB is lower than that of HA III. Ka value of HB is higher than that of HA Which ONE of the above statements is/are CORRECT? A I only B II only C I and II only D II and III only (2) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 7 QUESTION 2 (Start on a new page.) Consider the organic compounds A to F given in the table below. CH2CH3 A CH3CHCH2 C C CH CH2CH3 B propan-2-one CH3 C Bromomethane D C4H8O E C7H15COOH F Hexane 2.1 To which homologous series do the following compounds belong? 2.1.1 Compound A (1) 2.1.2 Compound C (1) 2.2 Write down a LETTER for the compound that meets the following description: 2.2.1 A carboxylic acid (1) 2.2.2 A compound whose formula is the same as the empirical formula of compound E (1) 2.3 Compound A is a hydrocarbon. 2.3.1 Define the term hydrocarbon. (2) 2.3.2 Is compound A SATURATED or UNSATURATED? Give a reason for the answer. (2) 2.3.3 Write down the IUPAC name of compound A. (3) 2.4 Write down the structural formula of compound B. (2) 2.5 Compound D, a straight chain molecule, has only ONE CHAIN ISOMER. For compound D write down the: 2.5.1 IUPAC name (2) 2.5.2 STRUCTURAL formula of its CHAIN ISOMER (2) Copyright reserved Please turn over

Downloaded from hlayiso.com 8 PHYSICAL SCIENCES P2 (EC/JUNE 2022) 2.6 A group of learners use compound F as a fuel by reacting it with excess oxygen. Write down the: 2.6.1 Name of the reaction between compound F and oxygen (1) 2.6.2 Write down a balanced equation for the reaction of compound F with excess oxygen, by using the MOLECULAR FORMULAE (3) 2.6.3 Give a reason why alkanes are used as fuel (1) [22] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 9 QUESTION 3 (Start on a new page.) 3.1 A group of learners compare the boiling points of THREE compounds A, B and C during an investigation. The compounds have comparable molecular mass. The data the learners obtained for the compounds is shown in the table below. Compound Boiling point (°C) A Pentane 36,1 B Butan-2-one 79,64 C Butan-1-ol 117,7 3.1.1 Define the term boiling point. (2) 3.1.2 Identify the independent variable for this investigation. (1) 3.1.3 Which intermolecular forces are comparable in this investigation? (1) 3.1.4 Explain why the boiling point of compound C is HIGHER than that of compound B by referring to TYPE, RELATIVE STRENGTHS of intermolecular forces and ENERGY. (4) 3.2 The graphs below show how the vapour pressure of compounds A and B (shown in the table above) changes with temperature. GRAPH OF TEMPERATURE VERSUS VAPOUR PRESSURE A B Vapour pressure (kPa) p1 36,1 79 Temperature (°C) 3.2.1 Define the term vapour pressure. (2) 3.2.2 Write down the value of p1 shown in the graph. (1) Copyright reserved Please turn over

Downloaded from hlayiso.com 10 PHYSICAL SCIENCES P2 (EC/JUNE 2022) 3.2.3 In what phase is compound A at 50 °C? Explain the answer. (2) 3.2.4 How would the vapour pressure of compound C compare, to that of compound A at 36,1 °C? Choose from HIGHER THAN, LOWER THAN or EQUAL TO. (1) 3.2.5 Explain your answer to QUESTION 3.2.4. (2) [16] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 11 QUESTION 4 (Start on a new page.) Consider the flow diagram given below. Compounds P, Q and R are organic products of reactions 1, 2 and 3 respectively. CH3CH2CH2CH2Br Reaction1 Alcohol P Reaction 2 Compound Q CH3COOH C4 Reaction 3 C4 A C4 Compound R (C4H8) For REACTION 1 write down the: C4 4.1 Name of the type of reaction taking place (1) 4.2 Condensed structural formula of compound P (2) 4.3 Is alcohol P a primary, secondary, or tertiary alcohol? Give a reason for the answer. (2) For REACTION 2 write down the: 4.4 Name of the reaction taking place (1) 4.5 IUPAC name and structural formula of the organic product Q (4) 4.6 Type of elimination reaction represented by REACTION 3 (1) 4.7 ONE reaction condition other than heat for REACTION 3 (1) Copyright reserved Please turn over

Downloaded from hlayiso.com 12 PHYSICAL SCIENCES P2 (EC/JUNE 2022) Compound R, C4H8, produced in reaction 3 in the flow diagram above is converted to compound T in a TWO step process as shown below. Compounds R and T are unbranched POSITIONAL isomers. STEP 1 Compound S STEP 2 Compound T R: C4H8 HBr 4.8 Define the term positional isomer. (2) 4.9 Write down a balanced equation using structural formulae for the reaction taking place in STEP 2. (6) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 13 QUESTION 5 (Start on a new page.) The decomposition of hydrogen peroxide represented by the balanced equation below is used to investigate the factors that influence reaction rate. H2O2(aq) → H2(g) + O2(g) ∆H < 0 5.1 Define reaction rate. (2) 5.2 Besides temperature, write down TWO factors that affect the rate of this reaction. (2) 5.3 During an experiment (experiment 1),150 cm3 of H2O2 decomposes at 30 °C in a flask. The graph below shows the results of experiment 1. Concentration of H2O2 (mol·dm-3) 1,0 0,2 0 2 000 5 000 Time (s) 5.3.1 Give a reason why the rate of reaction decreases between t = 2 000 s and t = 5 000 s. (2) 5.3.2 How long (in seconds) did the reaction take to reach completion? (1) Calculate the: 5.3.3 Average rate of reaction (3) 5.3.4 Volume of oxygen produced during the interval t = 0 to t = 2 000 s. Assume that the molar gas volume at 30 °C is 25 000 cm3·mol-1. ASSUME THAT THE VOLUME OF THE SOLUTION REMAINS CONSTANT. (5) Copyright reserved Please turn over

Downloaded from hlayiso.com 14 PHYSICAL SCIENCES P2 (EC/JUNE 2022) 5.4 How will the following be affected if the volume of hydrogen peroxide (H 2O2) used in experiment 1 is doubled? Choose from INCREASES, DECREASES or REMAINS THE SAME. 5.4.1 Average rate of reaction (1) 5.4.2 Total volume of oxygen produced (1) 5.5 In experiment 2 hydrogen peroxide decomposes under the same conditions as in experiment 1, but a small amount of manganese dioxide is added. The Maxwell-Boltzmann distribution curve for the reaction in experiment 1 and experiment 2 is shown below. Number of particles E2 E1 Kinetic energy E1 and E2 represent activation energies for the reaction in experiments 1 and 2. 5.5.1 Define activation energy. (2) 5.5.2 Describe what is represented by the shaded area in the graph. (1) 5.5.3 Which ONE of E1 or E2 would yield a higher reaction rate? Explain the answer by referring to the collision theory. (4) [24] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 15 QUESTION 6 (Start on a new page.) 6.1 The following reaction reaches equilibrium at a temperature of 327 °C. N2(g) + 3 H2(g) ⇌ 2 NH3(g) ∆H < 0 6.1.1 What is the meaning of the double arrow “⇌”? (1) How does the rate of the forward reaction compare to the rate of the reverse reaction during the following time intervals? Choose from HIGHER THAN, LOWER THAN or EQUAL TO. 6.1.2 Before equilibrium is reached for the first time (2) 6.1.3 At equilibrium (1) The reaction is started by placing 4,88 moles of N2 and 6,18 moles of H2 in a 2 dm3 sealed container and allowed to react. When equilibrium is established at 327 °C it is found the 41,48 grams of NH3 is present. 6.2 Calculate the equilibrium constant, Kc, at 327 °C. (8) 6.3 Write down the name of a factor that affects the value of Kc. (1) 6.4 The graph below shows how the percentage yield of NH3 varies with pressure at different temperature values. A % Yield NH3 B C Temperature (°C) Which graph (A, B or C) represents percentage yield values obtained at the HIGHEST pressure? Explain the answer by referring to Le Chatelier’s principle. (4) Copyright reserved Please turn over

Downloaded from hlayiso.com 16 PHYSICAL SCIENCES P2 (EC/JUNE 2022) 6.5 What effect will the following changes have on the yield of NH 3 at equilibrium? Choose from INCREASES, DECREASES or NO EFFECT. 6.5.1 More N2 is pumped into the container. (1) 6.5.2 A suitable catalyst is added. (1) 6.5.3 The volume of the container is increased at constant temperature. (1) [20] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 17 QUESTION 7 (Start on a new page.) 7.1 Sulphuric acid, H2SO4 ionises according to the balanced equation below: H2SO4 + H2O → H3O+ + HSO4 7.1.1 Define an acid according to the Lowry-Brønsted theory. (2) 7.1.2 Write down the formulae of the TWO bases in the reaction above. (2) 7.1.3 Identify a substance in the reaction that can act as an ampholyte in some reactions. (1) 7.2 The table below gives information about solutions of two acids and a salt. NAME OF SUBSTANCE FORMULA Ka value or pH Ethanoic acid CH3COOH Ka = 1,8 x 10-4 at 25 °C Sulphuric acid H2SO4 pH = 3 Sodium carbonate Na2CO3 pH = 7,8 7.2.1 Is CH3COOH a STRONG or a WEAK acid? Give a reason for the answer. (2) 7.2.2 Which acid, CH3COOH or H2SO4, would react faster with Na2CO3? Assume the acids have the same concentration and are in excess. (1) 7.2.3 Calculate the concentration of the H2SO4 solution. (4) 7.2.4 Explain by using a relevant equation, why the pH of Na2CO3 is greater than 7. (3) Copyright reserved Please turn over

Downloaded from hlayiso.com 18 PHYSICAL SCIENCES P2 (EC/JUNE 2022) 7.3 A standard solution is prepared by dissolving 1,74 g of Mg(OH)2 in water to make 200 cm3 of the solution. 7.3.1 Define the term standard solution. (2) 7.3.2 Show by calculation that the concentration of the Mg(OH)2 solution is 0,15 mol·dm-3. (2) A group of learners added 50 cm3 of a dilute hydrochloric acid solution to 40 cm3 of the standard solution of Mg(OH)2. The balanced equation for the reaction is: Mg(OH)2 + 2 HCℓ → MgCℓ2 + 2 H2O The diluted hydrochloric acid solution was obtained by adding 5 cm 3 of 10 mol·dm-3 of concentrated hydrochloric acid to water to produce 100 cm 3 of the diluted acid solution. ONE of the ions (OH- or H3O+) is found to be in excess at the completion of the reaction. 7.3.3 Calculate the concentration of the ions in excess. (9) [28] TOTAL: 150 Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 19 NATIONAL SENIOR CERTIFICATE NASIONALE SENIOR SERTIFIKAAT 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 Standaarddruk p 1,013 x 105 Pa Molar gas volume at STP Molêre gasvolume teen STD Vm 22,4 dm3∙mol-1 Standard temperature Standaardtemperatuur Tθ 273 K Charge on electron Lading op elektron e -1,6 x 10-19 C Avogadro’s constant NA 6,02 x 1023 mol-1 Avogadro se konstante TABLE 2: FORMULAE/TABEL 2: FORMULES m n m n= M or/of c = V or/of c = MV pH= -log[H3O+] N ca Va na Kw = [H3O+][OH-] = 1x10-14 n= N or/of = A cb Vb nb at/by 298 K V n= V o Eθcell = Eθcathode – Eθanode / Eθsel = Eθkatode – Eθanode Eθcell = Eθreduction – Eθoxidation / Eθsel = Eθreduksie – Eθoksidasie Eθcell = Eθoxidising agent – Eθreducing agent / Eθsel = Eθoksideermiddel – Eθreduseermiddel Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/JUNE 2022) PHYSICAL SCIENCES P2 20 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) Atoomgetal (III) (IV) (V) (VI) (VII) (VIII) KEY/ SLEUTEL Atomic number 1 2 2,1 H He 1 29 4 3 4 Elektronegatiwiteit Simbool 5 6 7 8 9 10 1,0 Li 1,5 Be 1,9 Symbol 2,0 B 2,5 C 3,0 N 3,5 O 4,0 F Ne Electronegativity Cu 7 9 11 12 14 16 19 20 11 12 63,5 13 14 15 16 17 18 0,9 Na 1,2 Mg Benaderde relatiewe atoommassa 1,5 Aℓ 1,8 Si 2,1 P 2,5 S 3,0 Cℓ Ar 23 24 Approximate relative atomic mass 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 1,5Ti 1,6 V 1,6 Cr 1,5 Mn 1,8 Fe 1,8 Co 1,8Ni 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 1,4Zr 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 1,6Hf 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 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 Copyright reserved