Gr12 Technical Sciences P2 (English and Afrikaans) 2021 Preparatory Possible Answers_hlayiso.com_.pdf

Downloaded from hlayiso.com GAUTENG DEPARTMENT OF EDUCATION/ GAUTENGSE DEPARTEMENT VAN ONDERWYS PREPARATORY EXAMINATION/ VOORBEREIDENDE EKSAMEN 2021 MARKING GUIDELINES/NASIENRIGLYNE 11102 TECHNICAL SCIENCES/TEGNIESE WETENSKAPPE (PAPER/VRAESTEL 2) 6 pages/bladsye 1

Downloaded from hlayiso.com 11102/21 QUESTION/VRAAG 1 1.1 C (2) 1.2 A (2) 1.3 A (2) 1.4 C (2) 1.5 C (2) 1.6 C (2) [12] 2

Downloaded from hlayiso.com 11102/21 QUESTION/VRAAG 2 2.1 A series of organic compounds that can be described by the same general formula and where each member differs from the next by CH2 group. / 'n Reeks organiese verbindings wat deur dieselfde algemene formule beskryf word en waarin die een lid van die volgende verskil met 'n CH2-groep. (2) 2.2.1 E (1) 2.2.2 A (1) 2.2.3 A (1) 2.2.4 F (1) 2.2.5 A OR/OF D (1) 2.3.1 H H H H H Criteria for marking/ Nasienkriteria  Double bond on correct position/ H C C C C C H Dubbelband op die regte posisie. H H H  5 carbon & 10 H atoms/5 koolstof- en 10 H-atome. (3) 2.3.2 H Criteria for marking/ Nasienkriteria H C H  6 carbon and 12 hydrogen atoms/ H H H H H 6 koolstof- en 12 waterstofatome H C C C C C C H  Correct side chains on the right H H H H H positions/Korrekte sykettings op die H C H regte posisies H (3) 2.4.1 Carbonyl (group) /Karboniel (groep) (1) 2.4.2 Propan-2-ol OR 2-propanol/Propaan-2-ol OF 2-propanol (2) [16] 3

Downloaded from hlayiso.com 11102/21 QUESTION/VRAAG 3 3.1 High energy of combustion./Combustion releases huge amounts of energy./ Highly exothermic. /Hoë verbrandingsenergie./Verbranding stel groot (2) hoeveelhede energie vry./Baie eksotermies. 3.2 Marking criteria/ Nasienkriteria  Appropriate scale on both Boiling points (°C)/Kookpunte (°C) axes/Toepaslike skaal op beide asse  Both axes labelled correctly/Beide asse is korrek gemerk  Line/curve of best fit drawn through the Number of carbon atoms/Aantal koolstofatome points/Lyn/kurwe van beste pas deur die punte getrek (4) 3.3 Boiling point increases with number of carbon atoms. /Kookpunt neem toe (2) met die aantal koolstofatome. 3.4 Van der Waals forces between alcohol molecules increase with increase in molecular size. /Van der Waals-kragte tussen alkoholmolekules neem toe (2) met toename in molekulêre grootte. 3.5 Hydrogen bonds between alcohol molecules are stronger than Van der Waals forces between molecules of alkanes. /Waterstofbindings tussen alkoholmolekules is sterker as Van der Waals-kragte tussen molekules van (2) alkane. 3.6 Petrol has a low boiling point, vaporises easily/is volatile/explosive/flammable/ easily combustible/vapours have a higher density than oxygen and when swallowed vapours can cause suffocation. /Petrol het 'n lae kookpunt, verdamp maklik/is vlugtig/plofbaar/vlambaar/maklik brandbaar/dampe het 'n hoër digtheid as suurstof en dampe kan verswelg indien dit ingesluk word. (2) [14] 4

Downloaded from hlayiso.com 11102/21 QUESTION/VRAAG 4 4.1 Addition/Addisie (1) 4.2 H H H H H H Marking criteria/ Nasienkriteria H H H C C C +  H C C C H O  Correct structural formula of H H H O H reactants/Korrekte H struktuurformule van reaktante Note: If condensed formula used: -1  Correct structural formula of product/Korrekte mark/Opmerking: Indien struktuurformule van produk gekondenseerde formule gebruik word: -1 punt (3) 4.3 H2O (1) 4.4.1 H H H Marking Criteria/Nasienkriteria  Br atom on carbon number 2 / H C C C H Br-atoom op koolstofgetal 2 H Br H (1) 4.4.2 Substitution /Substitusie (1) 4.5.1 Addition /Addisie (1) 4.5.2 Substitution /Substitusie (1) 4.5.3 The reaction takes place in the presence of an inert solvent/Die reaksie vind plaas in die teenwoordigheid van 'n inerte oplosmiddel (1) [10] 5

Downloaded from hlayiso.com 11102/21 QUESTION/VRAAG 5 5.1 Concentration/Konsentrasie = 1mol∙dm-3 Temperature/Temperatuur = 298 K/25 °C (2) 5.2 Zn to/na Cu (1) 5.3 From chemical to electrical energy / Van chemise tot elektriese energie (2) 5.4 It completes the circuit or It maintains electrical neutrality in the electrolytes (Accept any one.)/Dit voltooi die stroombaan of Dit handhaaf elektriese neutraliteit in die elektroliete (Aanvaar enige een.) (1) 5.5 A substance that is oxidised/loses electrons OR a substance that undergoes oxidation/ ʼn Stof wat geoksideer word/verlies aan elektrone OF ʼn stof wat oksidasie ondergaan 5.6 Zn → Zn2++ 2e- (2) 5.7 Cu2+ + 2e-→ Cu (2) 5.8 Zn + Cu2+ → Zn2++ Cu balanced reaction equation/ gebalanseerde reaksievergelyking  (3) 5.9 Anode: Zinc electrode/Sinkelektrode OR/OF Zn(s) Cathode/Katode: copper electrode/koper electrode OR/OF Cu(s) (2) 5.10 Zn/Zn2+//Cu2+/Cu ( for //) (3) 5.11 Ecell/sel = Ecathode/katode – Eanode/anode Ecell/sel = 0,34 – (–0,76)  Ecell/sel = 1,1 V  (3) [23] TOTAL/TOTAAL: 75 6