Physical Sciences Grade 11 P2 2020 Memo

NATIONAL SENIOR CERTIFICATE/ NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 11 NOVEMBER 2020 PHYSICAL SCIENCES P2/ FISIESE WETENSKAPPE V2 MARKING GUIDELINE/NASIENRIGLYN (EXEMPLAR/EKSEMPLAAR) MARKS/PUNTE: 150 This marking guideline consists of 12 pages./ Hierdie nasienriglyn bestaan uit 12 bladsye.

2 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/NOVEMBER 2020) QUESTION 1/VRAAG 1 1.1 A √√ (2) 1.2 C √√ (2) 1.3 D √√ (2) 1.4 C √√ (2) 1.5 A √√ (2) 1.6 B √√ (2) 1.7 A √√ (2) 1.8 A √√ (2) 1.9 D √√ (2) 1.10 B √√ (2) [20] QUESTION 2/VRAAG 2 2.1 The sharing of electrons between two atoms to form a molecule. 99 / Die deel van elektrone tussen twee atome om ʼn molekuul te vorm. (2) 2.2 H .. H : C : H 99 .. H (2) 2.3 2.3.1 C – H. 9 O-atom has a smaller atomic radius than the C-atom. 9 O-atoom het ʼn 2 kleiner atomiese radius as die C-atoom. OR/ OF C-atom has a larger atomic radius than the O-atom. C-atoom het ʼn groter atomiese radius as die O-atoom. (2)   2.3.2 O-H9 (1) 2.4 Two / Twee 9 OR/OF 2 (1) 2.5 NH4+ 9 (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/NOVEMBER 2020) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 3 2.6 N-atom is more electronegative than the H-atom. 9 The NH3 molecular geometry/charge distribution is asymmetrical 9 / The electron density (charges) will be distributed unevenly around the molecule. N-atoom is meer elektron-negatief as die H-atoom Die NH3 se molekulêre geometrie/lading is asimmetries versprei / Die elektrondigtheid (lading) sal oneweredig rondom die molekuul versprei wees. C-atom is more electronegative than the H-atom 9 but CH4 molecular geometry / charge distribution is symmetrical 9 C-atoom is meer elektron-negatief as die H-atoom maar die CH4 molekulêre geometrie/lading verspreiding is simmetries. (4) [13] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

4 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/NOVEMBER 2020) QUESTION 3/VRAAG 3 3.1 3.1.1 The temperature at which the vapour pressure of a liquid equals atmospheric pressure. 99 Die temperatuur waarteen die dampdruk van ʼn vloeistof gelyk aan die atmosferiese druk is. (2) 3.1.2 Gas 9 (1) 3.1.3 Dipole-dipole 9 (forces) / Dipool-dipool (kragte) (1) 3.1.4 B9 Compound B has larger molecular size 99 / Compound A has a smaller molecular size Verbinding B het ʼn groter molekulêre grootte / Verbinding A het ʼn kleiner molekulêre grootte. (3) 3.1.5 A9 Lower boiling point / 9 Laer kookpunt OR/OF B has a higher boiling point / B het ʼn hoër kookpunt (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/NOVEMBER 2020) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 5 3.1.6 Compound C/ HF has hydrogen bonds. 9 HCℓ (A) and HBr (B) have dipole-dipole forces. The hydrogen bonds / intermolecular forces in compound C / HF is stronger 9than the dipole-dipole forces / intermolecular forces in HCℓ (A) and HBr (B). Therefore more energy will be required to overcome the intermolecular forces in HF (A). 9 Verbinding C/HF het waterstofbindings. HCℓ (A) en HBr (B) het dipool-dipoolkragte. Die waterstofbinding/intermolekulêrekragte in verbinding C / HF is sterker as die die dipool-dipoolkragte/intermolekulêrekragte in HCℓ (A) en HBr (B). Daarom word meer energie benodig om die intermolekulêrekragte in HF (A te oorkom). OR/OF Compound C / HF has hydrogen bonds. 9 HCℓ (A) and HBr (B) have dipole-dipole forces. The dipole-dipole forces / intermolecular forces in compounds HCℓ (A) and HBr (B) is weaker 9than the intermolecular forces in HF (C) Therefore less energy will be required to overcome the intermolecular forces in HCℓ (A) and HBr (B). 9 Verbinding C / HF het waterstofbindings HCℓ (A) en HBr (B) het dipool-dipoolkragte Die dipool-dipool/intermolekulêre kragte in verbindings HCℓ (A) en HBr (B) is swakker as die waterstofbinding/intermolekulêrekragte in HF (C). Daarom word minder energie benodig om die intermolekulêrekragte in HCℓ (A) en HBr (B) te oorkom. 3.2 3.2.1 CCℓ4 9 (1) 3.2.2 CCℓ4 and I2 have London forces only. 9 H2O has (London forces) and hydrogen bonds 9 Intermolecular forces in solution are of comparable magnitude (CCl4) 9 OR IMF in solution are not of comparable magnitude (H2O) CCℓ4 en I2 het slegs Londenkragte H2O het (londenkragte) en waterstofbindings OF Intermolekulêrekragte in oplossing is van vergelykbare grootte. (3) [16] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

6 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/NOVEMBER 2020) QUESTION 4/VRAAG 4 4.1 Charles’ law 9 / Charles se wet (1) 4.2 4.2.1 What effect will a change in temperature have on the volume of the gas? 99/ What is the relationship between temperature and volume of gas? Watter effek sal die verandering in temperatuur op die volume van die gas hê? Wat is die verhouding tussen temperatuur en volume van die gas? Marking guideline/Nasienriglyn x Correct independent and dependent variable x Korrekte onafhanklike en afhanklike veranderlike x In the form of a question x In die vorm van ʼn vraag (2) 4.2.2 Pressure OR the amount of gas. Druk OF hoeveelheid gas Any one/Enige een 9 (1) 4.3 Thermometer/ Termometer 9 (1) 4.4 4.4.1 R = 273,08 9 (K) (4) 4.4.2 pV = nRT 9 p(66 10-3) 9 = (3)(8,31)(269) 9 p = 101 608,64 Pa 9 (5) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/NOVEMBER 2020) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 7 4.5 Low temperature 9 and high pressure 9/ Lae temperatuur en hoë druk (2) 4.6 H2 9 H2 has smaller molecules 9 and weaker intermolecular forces 9 / H2 het kleiner molekules en swakker intermolekulêrekragte. (3) [19] QUESTION 5/VRAAG 5 5.1 The minimum energy needed for a reaction to take place. 99 / Die minimum energie wat benodig word vir ʼn reaksie om plaas te vind. (2) 5.2 Reaction / Reaksie I. 9 The temperature of the reaction mixture increases. 9 Die temperatuur van die reaksiemengsel verhoog. (2) 5.3 NEGATIVE / NEGATIEF 9 (1) 5.4 Catalyst / Katalisator 9 (1) 5.5 LARGER THAN / GROTER AS 99 (2) 5.6 Potential energy Marking criteria / (kJ∙mol-1)/ Nasienkriteria Potensiële energie Correct shape 9 (kJ∙mol-1) Ea Korrekte vorm ΔH ΔH correctly indicated 9 ΔH korrek aangedui Ea correctly indicated 9 Ea korrek aangedui Time/tyd (3) [11] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

8 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/NOVEMBER 2020) QUESTION 6/VRAAG 6 6.1 6.1.1 The simplest whole number ratio of elements in a given compound 99 / Die eenvoudigste heelgetalverhouding van elemente in ʼn gegewe verbinding (2) 6.1.2 n (C) = 9 n (C) = 9= 4,55 mol n (H) = 9= 9,09 mol n (O) = 9= 2,27 mol n (C) : n (H) : n (O) 9 2 : 4 : 1 Empirical formula / Empiriese formule: C2H4O1 9 (6) 6.1.3 Ratio / Verhouding = Ratio / verhouding = 9 Ratio / verhouding = 2 Molecular formula / Molekulêre formule: C4H8O2 9 (2) 6.2 6.2.1 The amount of solute per litre/volume of solution 99 / Die hoeveelheid opgeloste stof per liter/volume van oplossing (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/NOVEMBER 2020) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 9 6.2.2 n= m/M = 8/40 9 = 0,2 mol for both formulae/ vir beide formules c = n/V = 0,2/0,25 9 = 0,8 mol.dm-3 9 Marking guide / Nasienriglyn x Formula / Formule 9 9 x Substitution of /substitusie van 8 and / en 0,25 or/ of 0,2 and 0,25 x Substitution of / substitusie van 40/ x Final answer / Finale antwoord (4) 6.3 NaN3 Any one / Enige een Mole ratio / molverhouding: NaN3 : N2 2 :3 n (N2) = n (N2) = 1,275 mol V = nVm V = (1,275)(22,4) V = 28,56 dm3 (5) [21] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

10 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/NOVEMBER 2020) QUESTION 7/VRAAG 7 7.1 The substance that is completely used-up in a chemical reaction. / Die stof wat volledig in ʼn chemiese reaksie opgebruik word. (2) 7.2 H2SO4 Mole ratio / mol verhouding = OR / OF Mole ratio / mol verhouding = Mole ratio / mol verhouding = = 0,5 Mole ratio / mol verhouding Mole ratio / mol verhouding = = 0,34 = =2 Ratio smaller than / Verhouding kleiner Mole ratio / mol verhouding as 0,5. = = 2,88 Ratio greater than / Verhouding groter as 2. H2SO4 is the limiting reagent / H2SO4 is die beperkende reagens. n [(NH4)2SO4 ]= = 20,41 m = nM m = (20,21)(132) m = 2 667,72 g (7) [9] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

(EC/NOVEMBER 2020) PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 11 QUESTION 8/VRAAG 8 8.1 8.1.1 A base is a proton/H+ ion acceptor. 99 / ʼn Basis is ʼn protoon/H+ ioon-aanvaarder (2) 8.1.2 HPO42- and/en PO43-9 OR/OF H3O+ and/en H2O (1) 8.1.3 ACIDIC / SUUR. 9 (Excess)/ (Oormaat) H3O+ 9 are produced / word geproduseer. (2) 8.1.4 HPO42 99 (2) 8.2 CuO + 2HNO39 Cu(NO3)2 + H2O9 9Balancing / Balansering Marking guide/ Nasienriglyn x Reactants / Reaktante x Products / Produkte x Balancing / Balansering (3) 8.3 8.3.1 Marking guide / Nasienriglyn x Formula / Formule n = cV x Substitution into / Substitusie in n= cV x Ratio / Verhouding CaCO3: H2SO4aCO3: H2SO4 x Formula / Formule n= m/M x Substitution / Substitusie of 100 into n = m/M x Calculation of / Berekening van % Purity / Suiwerheid x Final answer / Finale antwoord nacid reacting / suur wat reageer het= cV 9 = 1,5 x 200/1000 9 = 3 mol M (CaCO3) used / gebruik = nM 9 = 3 x 100 9 = 30 g + % Purity/ Suiwerheid = mpure/suiwer/mimpure/onsuiwer x 100 = 30/40 x 100 9 = 75% 9 (6) 8.3.2 c1V1 =c2V2 9 x 10 9 = 1,5 9V 60 cm3 = V solution / oplossing Vwater = 60 –10 9 = 50 cm3 9 (4) [20] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

12 PHYSICAL SCIENCES P2/FISIESE WETENSKAPPE V2 (EC/NOVEMBER 2020) QUESTION 9/VRAAG 9 9.1 9.1.1 Loss of electrons 99 / Verlies van elektrone (2) 9.1.2 Zn 99 (2) 9.1.3 Fe3+ + e- → Fe2+ 99 (2) 9.2 9.2.1 + 5 99 (2) 9.2.2 Ag (s) → Ag+ (aq) + e- 9 NO3 (aq) + 2 H+ + e → NO2 (g) + H2O 9 Ag (s) NO3 (aq) + 2 H+ → Ag+ (aq) + NO2 (g) + H2O 99 Marking guideline/ Nasienriglyn Correct oxidation half reaction / Korrekte oksidasie halfreaksie Correct reduction half reaction / Korrekte reduksie halfreaksie Final reaction correct / Finale reaksie korrek Balanced / Gebalanseerd (4) [12] QUESTION 10/VRAAG 10 10.1 10.1.1 Witwatersrand 9 (1) 10.1.2 Reduced 9 / Gereduseer/verminder Oxidation number (of Au) decreases 99 ( from +1 to 0) / Oksidasiegetal (van Au) verlaag (vanaf +1 tot 0) (3) 10.1.3 NaCN is harmful as it is poisonous to humans 99 / NaCN is skadelik omdat dit giftig is vir mense (2) 10.1.4 Smelting 9 (1) 10.2 10.2.1 Release of greenhouse gas / CO2 / Global warming 9 Air pollutions/toxins released into air. 9 Vrystelling van kweekhuisgas / CO2 / Aardverwarming / Lugbesoedeling / gifstowwe wat in die lug vrygestel word. (2) [9] TOTAL/TOTAAL: 150 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief