Gr 11 Physical Sciences P2 (English and Afrikaans) November 2022 Possible Answers_hlayiso.com_.pdf

Downloaded from hlayiso.com PROVINCIAL EXAMINATION/ PROVINSIALE EKSAMEN NOVEMBER 2022 GRADE/GRAAD 11 MARKING GUIDELINES/ NASIENRIGLYNE PHYSICAL SCIENCES: CHEMISTRY/ FISIESE WETENSKAPPE: CHEMIE (PAPER/VRAESTEL 2) 8 pages/bladsye

Downloaded from hlayiso.com MARKING GUIDELINES/ PHYSICAL SCIENCES/FISIESE WETENSKAPPE NASIENRIGLYNE (PAPER/VRAESTEL 2) GRADE/GRAAD 11 QUESTION/VRAAG 1 1.1 B ✓✓ (2) 1.2 D ✓✓ (2) 1.3 B ✓✓ (2) 1.4 C ✓✓ (2) 1.5 D ✓✓ (2) 1.6 C ✓✓ (2) [12] QUESTION/VRAAG 2 2.1 H ✓ Shape/Vorm • ✓ Electrons and charge/Elektrone en  • ladings H• C H • H (2) 2.2 covalent bond/kovalente binding (1) 2.3 2.3.1 ✓ Mg + 2e - ✓ Empty brackets/Leë hakies ✓ Cl + 2e- ✓ Cl Full brackets/Cl Vol hakies (4) 2.3.2 EN Cl = 3,0 Mg = 1,2 EN = 1,8✓  ionic/ionies  (2) [9] 2

Downloaded from hlayiso.com MARKING GUIDELINES/ PHYSICAL SCIENCES/FISIESE WETENSKAPPE NASIENRIGLYNE (PAPER/VRAESTEL 2) GRADE/GRAAD 11 QUESTION/VRAAG 3 3.1 Temperature at which the vapour pressure equals atmospheric pressure. ✓✓ Temperatuur waarby die dampdruk gelyk is aan die atmosferiese druk. ✓✓ (2) 3.2 The stronger the intermolecular forces, the higher the boiling point./The boiling point is proportional to the strength of intermolecular forces. ✓ Hoe sterker die intermolekulêre kragte, hoe hoër die kookpunt./Die kookpunt is eweredig aan die sterkte van die intermolekulêre kragte. ✓ NOTE/NOTA: NOT DIRECTLY proportional/NIE DIREK eweredig nie (1) 3.3 3.3.1 B/HCℓ ✓ Lowest boiling point (Vapour inversely proportional to boiling point.) ✓ Laagste kookpunt (Dampdruk omgekeerd eweredig aan kookpunt.) ✓ (2) 3.3.2 A/HF ✓ (1) 3.4 Boiling point of various hydrogen halides/Kookpunt van verskeie waterstofhaliede 40 20 0 HF HCl HBr HI -20 -40 -60 -80 -100 Hydrogen halides Hydrogen halides/Waterstofhaliede Marking criteria/Nasienkriteria Heading/Opskrif ✓ Labelling axes/Asse benoem ✓ Scale/Skaal ✓ Four points correctly plotted/Vier punte korrek geplot ✓✓ Line graph drawn/Lyngrafiek geteken ✓ (6) 3

Downloaded from hlayiso.com MARKING GUIDELINES/ PHYSICAL SCIENCES/FISIESE WETENSKAPPE NASIENRIGLYNE (PAPER/VRAESTEL 2) GRADE/GRAAD 11 3.5 • Hydrogen halides (A)/HF have a hydrogen bond ✓ while (D)/HI has dipole- dipole forces. ✓ • Intermolecular forces in hydrogen bond (A)/HF are stronger than intermolecular forces in dipole-dipole forces (D)/HI. ✓ • More energy is needed to overcome intermolecular forces in hydrogen bond (A)/HF than in dipole-dipole forces (D)/HI. ✓ • Waterstofhaliede(A)/HF het ʼn waterstofbinding ✓ terwyl (D)/HI ʼn dipool-dipool krag het. ✓ • Intermolekulêre kragte in waterstofbinding (A)/HF is sterker as die intermolekulêre kragte in dipool-dippool kragte (D)/HI. ✓ • Meer energie is nodig om die intermolekulêre kragte in waterstofbinding (A)/HF te oorkom as in dipool-dipool kragte. (D)/HI. ✓ (4) [16] QUESTION/VRAAG 4 4.1 It is a hypothetical gas that will obey all the gas laws under all conditions of pressure and temperature.  Dit is ʼn hipotetiese gas wat al die gaswette sal gehoorsaam onder alle toestande van druk en temperatuur.  (2) 4.2 pV = nRT  p x (0,012)  = 3 x 8,31 x (273 + 15,8)  p = 599 982 Pa   599,98 kPa  (5) 4.3 DECREASES/NEEM AF The pressure of a gas is inversely proportional to the volume of the gas at a specific temperature.  Die druk van ʼn gas is omgekeerd eweredig aan die volume van die gas by ʼn spesifieke temperatuur.  (2) [9] QUESTION/VRAAG 5 5.1 CO2✓ (1) 5.2 5.2.1 The amount of a substance having the same number of particles as there are atoms in 12 g carbon-12. ✓✓ Die hoeveelheid van ʼn stof wat dieselfde hoeveelheid deeltjies het as wat daar atome in 12g koolstof-12 is.  (2) 5.2.2 Na2CO3/Sodium carbonate ✓ because it reacts with excess hydrochloric acid. ✓ Na2CO3/Natriumkarbonaat ✓ want dit reageer met ʼn oormaat soutsuur. ✓ (2) 4

Downloaded from hlayiso.com MARKING GUIDELINES/ PHYSICAL SCIENCES/FISIESE WETENSKAPPE NASIENRIGLYNE (PAPER/VRAESTEL 2) GRADE/GRAAD 11 5.2.3 M(Na2CO3) = (2 x 23) + 12 + (3 x 16) M(Na2CO3) = 106 g.mol-1 n(Na2CO3) = = ✓ n(Na2CO3) = 0,1 mol n(Na2CO3) = n(CO2) = 0,1 mol ✓ m = nM ✓ = (0,1)(44) ✓ = 4,4 g ✓ (5) 5.2.4 n(CO2) = ✓ n(CO2) = ✓ n(CO2) = 0,217 mol n(CO2) = 2n(NaCl) = 2(0,217) ✓ n(NaCl) = 0,435 mol n(NaCl) = 0,435 = ✓ m = 25,44 g ✓ (5) 5.3 5.3.1 One mole of any gas occupies the same volume at the same temperature and pressure. ✓✓ Een mol van enige gas beslaan dieselfde volume by dieselfde temperatuur en druk. ✓✓ (2) 5.3.2 If 46 g occupies half of the molar gas volume, ✓ then the ratio is 2:1. ✓ Thus molecular formula to be able to occupy 22,4 dm 3 at STP is N2O4. ✓ Indien 46 g die helfte van die molêre gasvolume beslaan, ✓ dan is die verhouding 2:1 ✓ Die molekulêre formule wat in staat is om 22,4 dm3 by STD te beslaan is dus N2O4 ✓ (3) [20] 5

Downloaded from hlayiso.com MARKING GUIDELINES/ PHYSICAL SCIENCES/FISIESE WETENSKAPPE NASIENRIGLYNE (PAPER/VRAESTEL 2) GRADE/GRAAD 11 QUESTION/VRAAG 6 6.1 The surroundings will cool down. ✓✓ Die omgewing sal afkoel. ✓✓ (2) 6.2 E ✓ (1) 6.3 6.3.1 It will lower the activation energy ✓ by providing an alternative pathway. ✓ Dit sal die aktiveringsenergie verlaag ✓ deur ʼn alternatiewe pad te skep. ✓ (2) 6.3.2 Potential energy/ E Potensiële energie C B D F (kJ.mol-1) A Reaction pathway/ ✓✓ Reaksieverloop (2) 6.4 ΔH = D – A ✓✓ (2) [9] QUESTION/VRAAG 7 7.1 7.1.1 It is a proton (H+ ion) donor. ✓✓ Dit is ʼn proton (H+ - ioon) skenker. ✓✓ (2) 7.1.2 Conjugate acid/Gekonjugeerde suur: H2SO4(aq) ✓ − Conjugate base/Gekonjugeerde basis: SO 24 (aq) ✓ (2) 7.1.3 HSO4–1 ✓✓ OR/OF H2O (2) 6

Downloaded from hlayiso.com MARKING GUIDELINES/ PHYSICAL SCIENCES/FISIESE WETENSKAPPE NASIENRIGLYNE (PAPER/VRAESTEL 2) GRADE/GRAAD 11 7.2 7.2.1 An acid that ionises completely in water ✓ to form a high concentration of H3O+ ions. ✓ ʼn Suur wat volledig in water ioniseer ✓ om ʼn hoë konsentrasie H3O+ ione te vorm. ✓ (2) 7.2.2 nb = cbVb ✓ = (0,2)(20 x 10-3) ✓ = 4 x 10-3 mol ✓ (3) 7.2.3 na = nb na = (4 x 10-3) ✓ = 2 x 10-3 mol ✓ (2) 7.2.4 ca = ✓ = ✓ = 0,17 mol. dm -3 ✓ (3) [16] QUESTION/VRAAG 8 8.1 A reaction that involves an electron transfer.  ʼn Reaksie waartydens elektronoordrag plaasvind.  (2) 8.2 8.2.1 Aℓ → Aℓ 3+ + 3e–  (2) 8.2.2 Zn 2+ + 2e– → Zn  (2) 8.2.3 2Aℓ + 3Zn 2+ → 2Aℓ 3+ + 3Zn  (2) 8.3 The aluminium metal (Aℓ)  (1) Die aluminium metaal (Aℓ)  [9] TOTAL/TOTAAL: 100 7

Downloaded from hlayiso.com MARKING GUIDELINES/ PHYSICAL SCIENCES/FISIESE WETENSKAPPE NASIENRIGLYNE (PAPER/VRAESTEL 2) GRADE/GRAAD 11 Taxonomy Grid/Taksonomie Rooster Recall Comprehension Analysis Evaluation Q no: Mark Q no: Mark Q no: Mark Q no: Mark 1.1 2 1.2 2 1.5 2 1.3 2 1.4 2 1.6 2 Bonding 2.2 1 2.1 2 2.3.2 2 2.3.1 4 Inter molecular 3.1 2 3.2 1 3.5 4 3.3 3 3.4 6 Ideal gas 4.1 2 4.2 5 4.3 2 Quantitative 5.2.1 2 5.1 1 5.2.3 5 5.3.1 2 5.2.2 2 5.2.4 5 5.3.2 3 Energy 6.1 2 6.3.2 2 6.2 1 6.4 2 6.3.1 2 Types 7.1.1 2 7.1.2 2 7.2.4 3 7.2.1 2 7.1.3 2 7.2.2 3 7.2.3 2 8.1 2 8.3 1 8.2 6 Actual Total 18% 19 41% 40 35% 36 6% 5 Target Total 15% 15 40% 40 35% 35 10% 6 8