Physical Sciences Grade 10 P2 2018 Memo (Afr)

NATIONAL SENIOR CERTIFICATE/ NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 10 PHYSICAL SCIENCES: CHEMISTRY (P2) FISIESE WETENSKAPPE: CHEMIE (V2) NOVEMBER 2018 MARKING GUIDELINES/NASIENRIGLYNE MARKS/PUNTE: 150 These marking guidelines consist of 10 pages. Hierdie nasienriglyne bestaan uit 10 bladsye. NOTE/NOTA: Ignore 1.4/ Ignoreer 1.4 and Question 8.4 molecular formula not in CAPS /Vraag 8.4 molekulere formule nie in KABV MARKS/PUNTE: 141 Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences P1/Fisiese Wetenskappe V1 2 DBE/November 2018 CAPS/KABV – Grade10/Graad 10 – Marking Guidelines/Nasienriglyne QUESTION 1/VRAAG 1 1.1 C  (2) 1.2 C  (2) 1.3 B  (2) 1.4 (Ignore this question/Ignoreer hierdie vraag) 1.5 A  (2) 1.6 D  (2) 1.7 C  (2) 1.8 C  (2) 1.9 D  (2) 1.10 C  (2) [18] QUESTION 2/VRAAG 2 2.1 A pure substance consisting of one type of atom. /'n Suiwer stof wat uit een tipe atoom bestaan. (2) 2.2.1 P (1) 2.2.2 Q (1) 2.2.3 R (1) 2.3 Element  (1) 2.4 Evaporation /Verdamping (1) 2.5.1 Q: Boiling point /Kookpunt (1) 2.5.2 R: Magnetism /Magnetisme (1) [9] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences/P2/Fisiese Wetenskappe/V2 3 DBE/November 2018 CAPS/KABV – Grade/Graad 10 - Memorandum QUESTION 3/VRAAG 3 3.1 The temperature of the liquid at which the vapour pressure equals the external (atmospheric) pressure. /Die temperatuur van die vloeistof waarteen die dampdruk aan die eksterne (atmosferiese) druk gelyk is. (2) 3.2.1 80 °C  (1) 3.2.2 D (1) 3.2.3 C (1) 3.3 Liquid changes to gas /Vloeistof verander na gas (1) 3.4 Remains the same. /Bly dieselfde (1) _ 3.5 Energy is used to overcome the intermolecular forces. /Energie word gebruik om die intermolekulêre kragte te oorkom. No energy available to increase the kinetic energy of the particles. /Geen energie beskikbaar om die kinetiese energie van die partikels te verhoog nie. (2) 3.6 A _ Lowest boiling point. /Laagste kookpunt OR/OF Highest vapour pressure at a specific temperature./Hoogste dampdruk by ‘n spesifieke temperatuur (3) 3.7 Vapour pressure increases with an increase in temperature. /Dampdruk verhoog wanneer temperatuur verhoog. OR/OF Vapour pressure is proportional to temperature. /Dampdruk is direk eweredig aan temperatuur. (2) [14] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences/P2/Fisiese Wetenskappe/V2 4 DBE/November 2018 CAPS/KABV – Grade/Graad 10 - Memorandum QUESTION 4/VRAAG 4 4.1 The number of protons in an atom of an element /Die aantal protone in 'n atoom van 'n element (2) 4.2.1 30 14Si  28 14Si • Identification of element (Si)/ Identifiseer (2) element (Si) • Correct mass number and atomic number (A and Z)/Korrekte massagetal en atoomgetal (A en Z) • No mark for swopping of A and Z/Geen punt indien A en Z omgeruil word 4.2.2 P  / Sodium / Na/ Natrium (1) 4.2.3 2- S  • Identification of correct element (S)/Identifiseer korrekte element (S) (2) • Correct charge (2-)/Korrekte lading (2-) • Incorrect identification of element/Verkeerde element (0/2) 4.3.1 Rb2 O  (2) 4.3.2 Rb is in the same group as P / Na /Rb is in dieselfde groep as P/ Na OR/OF Rb is in group 1/Rb is in groep 1 ∴ has the same valency as P/ Na. / ∴ het dieselfde valensie as P/ Na. (2) 4.4 Increases. /Neem toe From P to R, the atomic radius gets smaller.  OR/OF The outer electrons get closer to the nucleus. Van P na R raak die atomiese radius kleiner./Die buite-elektrone kom nader aan die kern. The attraction between the nucleus and the outer electron gets stronger  ∴ more energy is needed to remove the electrons. /Die aantrekkingskrag tussen die kern en die buite-elektrone raak sterker ∴ meer energie is nodig om die elektrone te verwyder. (4) 4.5 10 (electrons)  2p ↑↓ ↑↓ ↑↓  2s ↑↓  1s ↑↓ (3) 4.6 Hund's rule /Hund se reël (1) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences/P2/Fisiese Wetenskappe/V2 5 DBE/November 2018 CAPS/KABV – Grade/Graad 10 - Memorandum 4.7 Relative atomic mass/Relatiewe atoommassa: (28×92,23 + 29×4,68 + 30×3,09) A𝑟 = 100  = 28,11 (u)  (3) [22] QUESTION 5/VRAAG 5 5.1 A change in which no new substances are formed. /'n Verandering waarin geen nuwe stowwe gevorm word nie. OR/OF A change in which energy changes are small in relation to chemical changes. /'n Verandering waarin energieveranderinge klein is in vergelyking met chemiese veranderinge. OR/OF A change in which mass, number of atoms and molecules are being conserved. /'n Verandering waarin massa, getal atome en molekule behoue bly. (2) 5.2.1 X (1) 5.2.2 Y (1) 5.3 Sublimation. /Sublimasie (1) 5.4 Colour change. /Kleurverandering Formation of gas /Vorming van gas Formation of a precipitate /Vorming van 'n neerslag Change in temperature /Verandering in temperatuur (Any two/Enige twee) (2) 5.5.1 Heat. /Hitte (1) 5.5.2 4Fe(s) + 3O2 (g) → 2Fe2 O3 (s) (4) Notes/Aantekeninge • Reactants; products; phases; balancing Reaktanse/produkte/fases/balansering Marking rule 6.3.10./Nasienreël 6.3.10. 5.6.1 States that, no matter how a chemical compound is prepared, it always contains the same elements in the same proportion by mass. /Stel dit dat dit nie saak maak hoe 'n chemiese binding berei word nie; dit bevat altyd dieselfde elemente in dieselfde verhouding by massa. (2) Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences/P2/Fisiese Wetenskappe/V2 6 DBE/November 2018 CAPS/KABV – Grade/Graad 10 - Memorandum 5.6.2 OPTION 1/ OPSIE 1: Mass of CO 2 in the 1st sample/Massa van CO 2 in die 1ste monster = 20 – 11,2 = 8,8 g Proportion of CO 2 in the 1st sample/Verhouding van CO 2 in die 1ste monster 8,8 = 20  ∴ Mass of CO 2 in the 2nd sample/Massa van CO 2 in die 2de monster 8,8 = 20 x 30  = 13,2 g (4) OPTION 2/ OPSIE 2: OPTION 3/ OPSIE 3: 100 g CaCO 3 → 44 g CO 2  20 g CaCO 3 → 11,2 g CaO  30 g CaCO 3 → x g CO 2  30 g CaCO 3 → x g CaO  30 x 44 x = 16, 83 g CaO x = 100  ∴ Mass of CO 2 in the 2nd sample/ Massa van x = 13,2 g CO 2 in die 2de monster = 30 – 16, 83 = 13,2 g [18] QUESTION 6/VRAAG 6 6.1.1 A (1) 6.1.2 B (1) 6.2 It is formed when a pool of delocalised electrons surround the positive metal ion core./Rooster metaal ione met wolk/poel gedelokaliseerde elektrone wat positiewe ioonkerne omring (2) 6.3 Ionic (bond) /Ioniese (binding) (1) 6.4.1 A pure substance consisting of two or more different elements. /'n Suiwer stof wat uit twee of meer verskillende elemente bestaan. (2) 6.4.2 Alkali earth  (metals)/Aardalkali (metale) (1) 6.4.3 1 (one/een)  (1) 6.4.4  xx  xx -  x x x Mg + 2 Cl xx Mg 2+ + 2 Cl x MgCl2 xx xx (3) [12] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences/P2/Fisiese Wetenskappe/V2 7 DBE/November 2018 CAPS/KABV – Grade/Graad 10 - Memorandum QUESTION 7/VRAAG 7 7.1 Hydrated: surrounded by water molecules/Gehidrateer: omring deur water molekules (1) 7.2 Na2 CO3 (s)→ 2Na+ (aq) + CO3 (aq) 2- Products:  Balancing: /Produkte:/Balansering: (2) 7.3.1 The amount of a substance having the same number of particles as there are atoms in 12 g carbon-12. /Die hoeveelheid van 'n stof met dieselfde getal partikels as wat daar atome in 12 g koolstof-12 is. (2) 7.3.2 Acid-base /gas forming (reaction)/Suur-basis/gasvormend (reaksie) (1) 7.3.3 n (HCl) c (HCl) =  V (HCl) n (HCl) 1=  0,005 n = 0,005 mol  (3) 7.4 POSITIVE MARKING FROM 7.3.3/ POSITIEWE NASIEN VANAF 7.3.3 n(NaCl) : n(HCl) = 1 : 1 1 Marking criteria/Nasienriglyne: n(NaCl) = 1 × 0,005 • Using ratio/Gebruik verhouding m • Formula/Formule n =  M n(NaCl) = 0,005 mol • Substituting of/ Invervanging van 0,005 m 𝑚 mol & 58,5 g∙mol-1 in n = M n(NaCl) =  • Final answer/Finale antwoord: 0,29 g  𝑀 𝑚 0,005 =  58,5 𝑚 = 0,29 g  (5) [14] QUESTION 8/VRAAG 8 8.1 A solution that conducts electricity (through the movement of ions). / 'n Oplossing wat elektrisiteit deur die beweging van ione gelei. NOTE/LET WEL: If learners refer to movement of electrons, a mark is (2) forfeited/Indien leerder verwys na beweging van elektrone, penaliseer met 1 punt. 8.2.1 What is the relationship between a type of substance and its (electrical) conductivity? /Wat is die verwantskap tussen 'n tipe stof en sy (elektriese) geleidingsvermoë? Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences/P2/Fisiese Wetenskappe/V2 8 DBE/November 2018 CAPS/KABV – Grade/Graad 10 - Memorandum OR/OF How does a type of substance affect the (electrical) conductivity of a substance? /Hoe beïnvloed 'n tipe stof die (elektriese) geleidingsvermoë van 'n stof? (2) Marking Criteria/Nasienriglyne: Dependent and independent variable correctly stated.  Afhanklike en onaafhanklike veranderlikes korrek genoem. Ask a question about the relationship between the independent and  dependent variables. Vra 'n vraag oor die verwantskap tussen die onafhanklike en afhanklike veranderlikes. 8.2.2 Conductivity /Geleidingsvermoë (1) 8.2.3 Type of a substance /Tipe stof (1) 8.2.4 Mass OR Temperature /Massa OF Temperatuur (1) 8.3.1 A solution of CaCl2 /'n Oplossing CaCl2 It is the strongest electrolyte /Dit is die sterkste elektroliet. OR/OF It has the highest concentration of (chloride) ions /Dit het die grootste getal (chloried) ione. (2) 8.3.2 A solution of sugar /'n Oplossing van suiker It contains no free ions. /Dit bevat geen vrye ione nie. (2) 8.4 n(C):C(H):n(O) [ ignore this question] m(C) m(H) m(O) : : M[C] M[H] M[O] Assume mass of 100 g of a sample/Aanvaar massa van 100 g van 'n monster 40 6,67 53,33 : :  12 1 16 3,33 : 6,67 : 3,33 3,33 6,67 3,33 : : 3,33 3,33 3,33 1 : 2 : 1 Empirical formula/Empiriese formule: CH2 O -1 M(CH2 O) = 12 + 2 + 16 = 30 g∙mol  180 Factor/Faktor = = 6 30 ∴ Molecular formula/Molekulêre formule is: C6 H12 O6  (7) [11] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences/P2/Fisiese Wetenskappe/V2 9 DBE/November 2018 CAPS/KABV – Grade/Graad 10 - Memorandum QUESTION 9/VRAAG 9 9.1 Precipitation reaction /Presipitasiereaksie (1) 9.2.1 Sulphate /Sulfaat (1) 9.2.2 BaCO 3 + 2HNO 3  → Ba(NO 3 ) 2 + CO 2 + H 2 O Reactants; products; balancing Reaktanse/produkte/ balansering (3) 9.3.1 m n(Na2 CO3 ) =  M 5 Marking criteria/Nasienriglyne: =  m 106 • Formula/Formule n = M  • Substitution/Invervanging  = 0,047 mol • Using ratio/Gebruik verhouding  • Multipy by/Vermenigvulding met n(BaCO3 ) : n(Na2 CO3 ) m 197 g∙mol-1 in n = M 1 : 1 • Final answer/Finale antwoord: 9,26 g  m(BaCO3 ) = n × M = 0,047 × 197 = 9,26 g  (Range/Gebied: 9,25 – 9,87) (5) 9.3.2 POSITIVE MARKING FROM 9.3.1/ POSITIEWE NASIEN VANAF 9.3.1 actual yield/werklike opbrengs % yield/opbrengs = × 100 theoretical yield/teoretiese opbrengs 8,3 = ×100  9,26 = 89,63% (Range/Gebied: 84,26 – 89,64) (2) [12] Copyright reserved/Kopiereg voorbehou Please turn over/Blaai om asseblief

Physical Sciences P1/Fisiese Wetenskappe V1 10 DBE/November 2018 CAPS/KABV – Grade10/Graad 10 – Marking Guidelines/Nasienriglyne QUESTION 10/VRAAG 10 10.1 Hydrosphere: includes all water of the earth found as liquid water  Hidrosfeer: sluit alle water van die aarde in wat as vloeibare water gevind word Biosphere: includes all the living organisms. /Biosfeer: sluit alle lewende organismes in (2) 10.2.1 (A) Transpiration /Transpirasie 10.2.2 (B) Condensation /Kondensasie 10.2.3 (C) Precipitation /Presipitasie (3) 10.3 (A) Energy gained /Energie gewen (B) Energy lost. /Energie verloor (2) 10.4 Roots of plants absorb water from the ground. /Plantwortels absorbeer water uit die grond. Plants release the water to the atmosphere by transpiration. /Plante stel water deur transpirasie aan die atmosfeer vry. The water condenses to form clouds. /Die water kondenseer om wolke te vorm. Then water falls back to the ground by precipitation. /Water val dan terug grond toe deur presipitasie. (4) [11] TOTAL/TOTAAL: 150/ FINAL TOTAL: 141 Copyright reserved/Kopiereg voorbehou