Physical Sciences Grade 11 P2 Gauteng November 2023 QP (Eng)

Downloaded from hlayiso.com PROVINCIAL EXAMINATION 2023 NOVEMBER 2023 GRADE 11 PHYSICAL SCIENCES: CHEMISTRY PAPER 2 TIME: 3 hours MARKS: 150 11 pages + 4 data sheets P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 2 (PAPER 2) GRADE 11 INSTRUCTIONS AND INFORMATION 1. Write your name in the appropriate space in the ANSWER BOOK. 2. This question paper consists of NINE questions. Answer ALL 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 subquestions, 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, etc. where required. 12. Write neatly and legibly. P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 3 (PAPER 2) GRADE 11 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, for example 1.11D. 1.1 Which of the bonds between the atoms below has the highest polarity? A H–N B H - Cℓ C H–O D H–C (2) 1.2 The graph below shows how the potential energy varies with distance between the nuclei of two oxygen atoms when a double bond between the oxygen atoms (O = O) is formed. Potential energy (kJ.mol-1) Distance between nuclei (pm) Choose from the table below, the bond length and bond energy for O = O. BOND LENGTH (pm) BOND ENERGY (kJ∙mol-1) A 110 – 138 B 120 – 495 C 130 – 138 D 140 – 495 (2) 1.3 Consider the following statements: Which of the following is/are TRUE? (i) Most elements consist of atoms. (ii) Some elements consist of molecules. (iii) All compounds consist of molecules. (iv) Salt crystals are ionic compounds. A Only (i) B (i), (ii) and (iii) C (ii) en (iv) D (i), (ii) en (iv) (2) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 4 (PAPER 2) GRADE 11 1.4 Intermolecular forces influence some physical properties of materials like surface tension. Which of the following statements is correct? A The stronger the intermolecular force, the higher the surface tension. B The stronger the intermolecular force, the higher the rate of evaporation. C The stronger the intermolecular force, the lower the melting point. D The weaker the intermolecular force, the higher the boiling point. (2) 1.5 Determine what the new pressure in kPa will be if 750 ml nitrogen gas in the atmosphere is compressed to 500 ml, keeping the temperature constant? A 2,70 x 10 -4 kPa B 67,53 kPa C 151,95 kPa D 1,5 atm (2) 1.6 Hydrogen gas is a real gas that reacts like an ideal gas in the following situation: A There are no attractive or repulsive forces between the molecules at high temperatures. B The collisions between the molecules are perfectly elastic. C There is no movement of the molecules at zero Kelvin. D It forms a liquid at high pressures. (2) 1.7 A standard solution ... A contains one mole of solute per dm3. B must always be made up to 1 dm3. C is a solution of which the concentration is precisely known. D is a solution made up of oxalic acid. (2) 1.8 Which of the following is NOT a conjugate acid-base pair? A HCℓ and Cℓ- B HCO3- and H2CO3 C HSO−4 and H2SO4 D OH- and H3O+ 1.9 Instant hot and cold packs function by dissolving a salt into water. As the salt dissociates, heat is either released in an exothermic reaction or absorbed in an endothermic reaction. Which of the following reactions will be best suited to be used as a hot pack? A CH3COOMg + 4 H2O → CH3COOMg.4H2O ∆H = -13,3 kJ.mol-1 B CH3COONa + 3 H2O → CH3COONa.3H2O ∆H = -19,7 kJ.mol-1 C Ba(OH)2 + H2O → Ba 2+ + 2OH - + H2O ∆H = + 21,9 kJ.mol-1 D NH4NO3 + H2O NH4 + + NO3 - + H2O ∆H = +25,4 kJ.mol-1 (2) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 5 (PAPER 2) GRADE 11 1.10 Consider the reaction: Pb(s) + Cu2+(aq) Pb2+(aq) + Cu(s) The oxidised product is ... A Pb. B Pb2+. C Cu. D Cu2+. (2) [20] QUESTION 2 (Start on a new page.) Calcium carbonate is a dietary supplement used when the intake of calcium through the diet is not enough. The body requires calcium to maintain healthy bones, muscles, nervous system and heart. Calcium carbonate can also be used as an antacid to relieve heartburn. Calcium carbonate can be produced with the following reaction: CaO + CO2 CaCO3 2.1 Draw a Lewis diagram for: 2.1.1 CO2 (2) 2.1.2 Ca2+ (2) 2.2 Define a covalent bond. (2) 2.3 Identify the metal in the above reaction. (1) 2.4 Explain a metallic bond. (2) 2.5 Which of the two reactants in this reaction would most likely be: 2.5.1 A gas at room temperature? (1) 2.5.2 A solid at room temperature? (1) 2.6 Define electronegativity. (2) 2.7 Use electronegativity to determine the type of bonds that will form in CaO. (2) 2.8 Will CO2 be a polar or non-polar molecule? (1) 2.9 Explain the answer to QUESTION 2.8 by using a calculation and referring to the shape of the molecule. (2) [18] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 6 (PAPER 2) GRADE 11 QUESTION 3 (Start on a new page.) The physical properties of matter, such as vapour pressure, melting or boiling points, depend on intermolecular forces. 3.1 Define the term boiling point. (2) 3.2 Group 17 on the periodic table forms diatomic molecules, e.g. F2 and Cℓ2. 3.2.1 What type of intermolecular forces will there be between the molecules? (1) 3.2.2 Which ONE of the following halogens will have the highest boiling point? Cℓ2 or I2. (1) 3.2.3 Explain your answer to QUESTION 3.2.2. (3) 3.3 Study the following substances: HCℓ, Cℓ2, NH3, CO2, CaCℓ2 Which of the above will have: 3.3.1 Hydrogen bonds? (1) 3.3.2 Dipole-dipole forces? (1) [9] QUESTION 4 (Start on a new page.) Learners conducted an investigation to determine the relationship between the pressure and volume of a given mass of O2 gas, while keeping the temperature constant. Volume scale Air Glass tube Pressure gauge Oil foot pump P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 7 (PAPER 2) GRADE 11 They made the sketch graph below, to show their results: 4.1. Write a suitable investigative question for this investigation. (2) 4.2. Write down the: 4.2.1 Independent variable (1) 4.2.2 Controlled variable (1) 4.3 Name and state the law that is being investigated here. (3) 4.4 Calculate the value of X using other values given on the graph. (3) 4.5 Like all real gases, this gas will liquify at very low temperatures. Explain why this happens. (2) 4.6 If this experiment was conducted at a room temperature of 25 ˚C, calculate the amount of mole of O2(g) at a pressure of 200kPa. (4) A sealed glass tube with 20 cm3 of nitrogen gas is heated. 4.7 Define temperature. (2) 4.8 Use the kinetic theory to describe how the above change will influence the pressure experienced by the 20 cm3 N2(g). (3) [21] QUESTION 5 (Start on a new page.) 5.1. Aspirin is known by the chemical name acetylsalicylic acid. The empirical formula of aspirin consists of 60,0% carbon and 4,44% hydrogen and oxygen. 5.1.1 Define the term empirical formula. (2) 5.1.2 Determine the empirical formula of aspirin. (6) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 8 (PAPER 2) GRADE 11 5.1.3 If the molecular mass of aspirin is 180 g.mol-1, what is its molecular formula? (2) 5.2 The molar mass of hydrated sodium carbonate is found to be 268 g∙mol -1. The formula of the hydrated sodium carbonate is Na2CO3.xH2O. Calculate the number of moles of water (x) in the compound. (4) [14] QUESTION 6 (Start on a new page.) 6.1 If a solution of silver nitrate (AgNO3) is mixed with solution of potassium chloride (KCℓ), a precipitate of AgCℓ is produced according to the following reaction: KCℓ(aq) + AgNO3(aq) → AgCℓ(s) + KNO3(aq) 55 cm3 of a potassium chloride solution with a concentration of 0,25 mol.dm -3 is added to 70 cm3 of a silver nitrate solution with a concentration of 0,15 mol.dm-3. 6.1.1 What is meant by limiting reagent? (2) 6.1.2 Determine which substance is the limiting reagent. (5) 6.1.3 What mass of AgCl has precipitated? (4) 6.2 Mary heats 50 g of CaCO3 that reacts according to the following reaction: CaCO3 → CaO + CO2 She collects the formed CO2 gas. 6.2.1 Determine the number of moles of the CaCO3. (3) 6.2.2 She obtains only 18,2 g CO2 gas. Determine the percentage purity of the CaCO3. (5) 6.2.3 Calculate the mass of CO2 gas that Mary could collect if CaCO3 was only 70% pure. (5) [24] QUESTION 7 (Start on a new page.) 7.1 Sulphuric acid is a strong acid and an example of a diprotic acid. 7.1.1 Define an acid in terms of the Lowry-Brønsted theory. (2) 7.1.2 Give a reason why sulphuric acid is referred to as a diprotic acid. (2) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 9 (PAPER 2) GRADE 11 HSO− 4 can behave either as an acid or a base. 7.1.3 Write down ONE word for the underlined phrase in the above sentence. (1) 7.2 A learner uses a standard solution of sodium hydrogen carbonate to determine the concentration of a sulphuric acid solution. 7.2.1 What is meant by a “standard solution”? (2) 7.2.2 Write down the balanced equation for the reaction of sulphuric acid with water. (3) 7.3 In a titration, the learner finds that 20 cm3 of a 0,2 mol.dm-3 solution of sodium hydrogen carbonate neutralises 12 cm3 of the sulphuric acid solution. The balanced equation for this reaction is: 2NaHCO3 + H2SO4→ Na2SO4 + 2CO2 + 2H2O 7.3.1 Calculate the concentration of the H2SO4 solution. (5) 7.3.2 Which of the indicators listed below should be used in this titration? Briefly explain your answer. Indicator pH range in which the colour changes Methyl orange 3,1 – 4,4 Bromothymol blue 6,0 – 7,6 Phenolphthalein 8,3 – 10,0 (3) [18] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 10 (PAPER 2) GRADE 11 QUESTION 8 (Start on a new page.) Certain chemical reactions are often used to reduce swelling after an athletic injury. In a lab experiment the following reaction was tested and the sketch graph below was obtained. NH4Cℓ + H2O → NH4 + + Cℓ - + H2O Course of the reaction 8.1 Is this an exothermic or endothermic reaction? (1) 8.2. Explain the answer to QUESTION 8.1. (2) 8.3. State the enthalpy of this reaction. (2) 8.4 Which number on the graph represents the enthalpy for the reverse reaction? (1) 8.5 Define activation energy. (2) 8.6 Give the number on the graph that represents the activated complex. (1) 8.7 Explain how a catalyst would affect the activation energy in the reaction. (2) 8.8 Redraw the sketch graph on you answer sheet and use a dotted line to indicate the changes after adding a catalyst. (2) [13] P.T.O.

Downloaded from hlayiso.com QUESTION 9 (Start on a new page.) 9.1 Oxidation numbers make it easier to determine whether an element or a substance is oxidised or reduced during a chemical reaction. 9.1.1 Define oxidation in terms of oxidation numbers. (2) 9.1.2 Calculate the oxidation number of chromium in Cr2O72−. (2) 9.2 Consider the UNBALANCED equation below: Fe2+(aq) + Cℓ2(g) → Fe3+(aq) + Cℓ- 9.2.1 Give a reason why the reaction above is a redox reaction. (1) 9.2.2 Identify the FORMULA of the reducing agent. Explain the answer in terms of the oxidation number. (2) 9.2.3 Write down the reduction half-reaction. (2) 9.2.4 Write down the balanced net redox reaction. (4) [13] TOTAL: 150 END

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 12 (PAPER 2) GRADE 11 DATA FOR PHYSICAL SCIENCES GRADE 11 PAPER 2 (CHEMISTRY) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 11 VRAESTEL 2 (CHEMIE) TABLE 1: PHYSICAL CONSTANTS/TABEL 1: FISIESE KONSTANTES NAME/NAAM SYMBOL/SIMBOOL VALUE/WAARDE Avogadro's constant NA 6,02 x 1023 mol-1 Avogadro se konstante Molar gas constant R 8,31 J∙K-1∙mol-1 Molêre gaskonstante 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 TABLE 2: FORMULAE/TABEL 2: FORMULES p1V1 p 2 V2 = pV = nRT T1 T2 m N n= n= M NA V n m n= c= OR/OF c= Vm V MV ca Va n 𝑄 Q = na n= or/of n = cb Vb b 𝑒 𝑞𝑒 END

Downloaded from hlayiso.com FISIESE WETENSKAPPE: CHEMIE 13 (VRAESTEL 2) GRAAD 11 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/ 1 KEY/SLEUTEL Atoomgetal 2 2,1 H He 1 4 29 3 4 Electronegativity/ Symbol/ 5 6 7 8 9 10 1,0 Li 1,5 Be Elektronegatiwiteit 1,9 Cu Simbool 2,0 B 2,5 C 3,0 N 3,5 O 4,0 F Ne 7 9 11 12 14 16 19 20 63,5 11 12 13 14 15 16 17 18 Na Mg Aℓ Si P S Cℓ Ar 0,9 23 1,2 24 Approximate relative atomic mass/ 1,5 27 1,8 28 2,1 31 2,5 32 3,0 35,5 40 Benaderde relatiewe atoommassa 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 58 59 60 61 62 63 64 65 66 67 68 69 70 71 226 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

Downloaded from hlayiso.com FISIESE WETENSKAPPE: CHEMIE 14 (VRAESTEL 2) GRAAD 11 TABLE 4A: STANDARD REDUCTION POTENTIALS TABEL 4A: STANDAARD REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E (V) F2(g) + 2e− ⇌ 2F− + 2,87 3+ Co + 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− ⇌ 3+ 2Cr + 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 − NO 3 + 4H+ + 3e− ⇌ NO(g) + 2H2O + 0,96 Increasing reducing ability/Toenemende reduserende vermoë 2+ Hg + 2e − ⇌ Hg(ℓ) + 0,85 Ag+ + e− ⇌ Ag + 0,80 Increasing oxidising ability/Toenemende oksiderende vermoë − 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 2+ Cu + 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 2+ Fe + 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

Downloaded from hlayiso.com TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E (V) Li+ + e− ⇌ − 3,05 Increasing reducing ability/Toenemende reduserende vermoë Li Increasing oxidising ability/Toenemende oksiderende vermoë 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 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 2+ Cu + e − ⇌ Cu + + 0,16 2− SO 4 + 4H+ + 2e− ⇌ SO2(g) + 2H2O + 0,17 2+ Cu + 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− ⇌ 3+ 2Cr + 7H2O + 1,33 Cℓ2(g) + 2e − ⇌ 2Cℓ − + 1,36 − MnO 4 + 8H+ + 5e− ⇌ 2+ Mn + 4H2O + 1,51 + H2O2 + 2H +2 e − ⇌ 2H2O +1,77 Co3+ + e− ⇌ Co2+ + 1,81 F2(g) + 2e− ⇌ 2F− + 2,87