Physical Sciences Grade 11 Paper 2 KZN November 2023 Memo

Downloaded from hlayiso.com KWAZULU-NATAL PROVINCE EDUCATION REPUBLIC OF SOUTH AFRICA NATIONAL SENIOR CERTIFICATE �-------------------- ,. TRY) N , � � ��---------------------------------------------� � MARKS: 150 TIME 3 Hours This question paper consists of 13 pages and 4 data sheets. Copyright reseNed Please turn over

Downloaded from hlayiso.com Dosa koades2from Stanmoreph Si@S.COM November 2023 Examination INSTRUCTIONS AND INFORMATION i. Write your centre number and examination number in the appropriate spaces on the ANSWER BOOK. 25 This question paper consists of NINE questions. Answer ALL the questions in the AN R BOOK. 3. Start 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 sub-questions, for example between QUESTION 2.1 and QUESTION 2.2. 6. You may use a non-programmable calculator. 7s 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 et cetera where required. i2: Write neatly and legibly. Copyright reserved Please turn over

Downloaded from hlayiso.com PhysicADsueutemeled from Stanmoreph 'SicSs.com November 2023 Examination QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A-D) next to the question number (1.1 to1.10) in the ANSWER BOOK, for example 1.11 D. Ui Which of the following statements is CORRECT for an ENDOTHERMIC REAC ? A mperature of the surrounding increases. The enthalpy change for the reaction is negative. B C Heat flows from the surroundings into the system. D The enthalpy of the products is less than the enthalpy of the reactants. (2) 1.2 Two different gases, occupying the same volume at STP, will have the same... A mass. B mass to volume ratio. C molar mass. D number of molecules. (2) 13. Which of the following statements best describes a POLAR COVALENT BOND between two atoms? A Aband of delocalised electrons attract the nuclei of the two atoms. ut hared unequally between the two atoms. electronegativity between the two atoms is zero. 0 Oo DB ansferred from the less electronegative atom to the more om. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Physicsuentoneded from Stanmoreph SiCS.COM November 2023 Examination 1.4 The energy changes represented by X, Y and Z on the potential energy graph below takes place during a catalysed, reversible chemical reaction. Potential energy (kJ) Course of reaction Which ONE of the following represents the heat of the reaction for the FORWARD reaction? A Y-Xx B Y-Z é 2Z-« D X-z (2) 15 The shape of the PCfs molecule as predicted by the VSEPR theory is ... A _ tetrahedral. B trigonal planar C trigonal pyramidal. eo] trigonal bi-pyramidal. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com PhysiciDsuewtsmeled From Stanmorephysics.com _ November 2023 Examination NS 1.6 The sketch shows two containers, X and Y, connected by a tube containing a closed stopcock. stopcock The volume of container X is V and contains a gas at a pressure p. Container Y is evacuated. The volume of the tube is negligible. When the stopcock is opened at constant temperature the pressure of the gas in container X changes to 3. What is the volume of container Y? af A 3” 2 =V B 3 Cc & Vv 4 D 4 Vv 3 (2) 1:7 Consider the reaction represented by the balanced equation below: HsPOa(aq) + H2O0(t) — HsO*(aq) + H2POs¢(aq) Which ONE of the following is a conjugate acid-base pair? A H3POa(aq) and H2zPOa- (aq) B —_HsO0*(aq) and H2PO¢ (aq) C — HsPOa(aq) and H2O(2) D ~—_HsPOa(aq) and H3O*(aq) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Physicsuentoneded from Stanmoreph SiCS.COM November 2023 Examination 1.8 The number of ions present in 5 moles of aluminium oxide, Af2Os, is given by... A 10x 6,02 x 107° B 5x6,02 x 103 C 254Kl6,02 x 1028 D 02 x 1078 a (2) 1.9 In which ONE of the following reactions is HCf the REDUCING AGENT? A HCf(aq) + H2O0(t) — HsO*(aq) + Ch B NHsa(aq) + HCf(aq) — NHaCf(aq) Cc MnO2(aq) + 4HCf(aq) — MnCk(aq) + H2O0(f) + Cfha(g) D CaCOs(s) + 2HC£(aq) — CaCte(aq) + H20(%) + CO2(g) (2) 1.10 Consider the following reactions of a metal P: (i) P reacts with a solution of silver nitrate to form a deposit of metallic silver. (ii) P does not react with a solution of zinc sulphate. Which ONE of the following statements is CORRECT for reactions (i) and (ii)? A P is a reducing agent in both reactions. B P is an oxidising agent in both reactions. Cc P is an oxidising agent in reaction (i) only. D P is a reducing agent in reaction (i) only. bed Copyright reserved Please turn over

Downloaded from hlayiso.com Physicsuentoneded from Stanmoreph SiCS.COM November 2023 Examination QUESTION 2 (Start on a new page.) The letters A to F in the table below represent six covalent molecules. MOLECULE fiz7 A B Cc D E F FORMULA /D/i9/ H2O NH3 HF OF 2 HOC? HCN 2.1 Define the télm lone pair of electrons. (2) 2.2 Draw Lewis structures for the following molecules: 2.2.1 H20 (2) 2.2.2 HOCE (2) 2.3. For molecule A, write down the: 2.3.1 | Number of bonding pairs of electrons. (1) 2.3.2. Number of lone pairs of electrons. (1) 2.4 Consider the bond between the O and the H atoms in molecule A, and that between the O and the F atom in molecule D. Which of these two bonds, O-H or O-F, is more polar? Give a reason for the answer. (3) 2.5 What is the shape of molecule A? (1) 2.6 Write down the letter of the molecules that has the same shape as molecule A. (1) 2.7 Refer to the polarity and intermolecular forces of A and B to explain why molecule B is soluble in molecule A. (2) 2.8 The results in the table below were obtained during an investigation to determine the values of the bond length of the different bonds in molecule F (HCN). BONDING ATOMS BOND LENGTH (nm) CandH 0,109 CandN 0,116 2.8.1 Define bond length. (2) 2.8.2 Explain why the bond length for the bond between the C and N atoms is longer than the bond length between the C and H atoms. (2) 2.8.3. What is the bond order for the bond between the C and N atoms? (2) [21] Copyright reserved Please turn over

Downloaded from hlayiso.com PhysiciDsuewtsmeled from Stanmorephysics.com _ November 2023 Examination NS QUESTION 3 (Start on a new page.) During an investigation, the BOILING POINTS of the hydrides of two group VI elements were determined.The results of the investigation are shown in the table below. 3.1 3.2 3.3 3.4 3.5 3.6 3.7 elt Compound Formula Boiling Point (°C) mae P H2S Xx saa] Q H20 100 Define boiling point. (2) Write down the dependent variable for this investigation. (1) Write down the name of the strongest intermolecular forces that exist between molecules of: 3.3.1 P (1) 3.3.2 Q (1) Will the value X, in the table be EQUAL TO, LESS THAN or GREATER THAN 100 °C? (1) Fully explain the answer to QUESTION 3.5. (2) The boiling point of the hydride of a third group VI element, Se, is now determined. Will the boiling point of HaSe be EQUAL TO, LESS THAN or GREATER THAN that of H2S? Give a reason for the answer. (2) Will the boiling point of ammonia (NHs), be EQUAL TO, LESS THAN or GREATER THAN 100 °C? Fully explain the answer. (4) [14] Copyright reserved Please turn over

Downloaded from hlayiso.com PhysicADsueutemeled from Stanmoreph SicS.cOom November 2023 Examination QUESTION 4 (Start on a new page.) 4.1 The relationship between pressure and volume of an enclosed gas at 25 °C is investigated, by varying the pressure exerted by the gas, and observing the correspon volume occupied by the gas in each case. The resul ained are shown in the table below: fal RESSURE (kPa) | Volume in cm? 3 in cm? 60 50 0,020 D 35 0,029 100 30 0,033 150 20 0,050 200 15 0,067 4.1.1 NAME and STATE the gas law being investigated. (3) 4.1.2 | Write down TWO controlled variables for this investigation. (2) 4.1.3 Write down the dependent variable for this investigation. (1) 4.1.4 Use the results in the table to explain why a graph of pressure(p) versus the inverse of volume ( ) will be a straight line graph. (3) 4.1.5 Calculate the value represented by the letter D in the table. (2) 4.2 The graphs, A and B below were obtained during an investigation to identify the conditions under which a gas will deviate from ideal gas behaviour. Pressure 4.2.1. Which graph, A or B represents the deviation from ideal gas behaviour? (1) 4.2.2 State the relevant condition under which the deviation from ideal behaviour referred to in QUESTION 4.2.1 occurs. (2) 4.2.3. Explain the answer to question 4.2.2. (3) [17] Copyright reserved Please turn over

Downloaded from hlayiso.com PhysiciDsuewtsmeled from Stanmorephysics.com November 2023 Examination NS QUESTION 5 (Start on a new page) The balanced equation below represents a hypothetical reaction: x) + Y(Q) > XY(9) The table. w shows the different energies for the above reaction. ——t, | Energy of the Reactants (Er) | 351 kJ.mol? Energy of the Products (Ep) 109,2 kJ.mol+ Activation energy (Ea) 1370 kJ.mol* 5.1 Is the above reaction EXOTHERMIC or ENDOTHERMIC? Give a reason for the answer by referring to the data in the table. 5.2 Calculate the heat of reaction for the above reaction. 5.3 Define the term activated complex. 5.4 Sketch a potential energy versus course of reaction graph for the above reaction. The graph need not be drawn to scale. Clearly label the axes and indicate the following numerical values on the Y-axis. e Energy of the reactants e Energy of the products e Energy of the activated complex 5.5 The following reaction NOW takes place: XY(g) > X(g) + Y(g) For the above reaction write down the value of the: 5.5.1 Heat of reaction. 5.5.2. Activation energy. QUESTION 6 (Start on a new page) A compound contains 30,4 % nitrogen and 69,6 % oxygen by mass. 6.1 Define the term empirical formula. 6.2 Determine the empirical formula of the compound. 6.3 Write down the molecular formula of the compound if the molecular mass of the compound is 92 g.mol?. (2) (3) (2) (5) (1) (2) [15] (2) (5) (2) [9] Copyright reserved Please turn over

Downloaded from hlayiso.com Physicsuentoneded from Stanmorephysics.com November 2023 Examination QUESTION 7 (Start on a new page.) A sample of IMPURE solid calcium carbonate, CaCOs, of mass 12,5 g reacted with dilute £(aq), according to the following balanced equation: 8) + 2HCL(aq) > CaCh(aq) + CO2g) + H2O(2) The graph belobrstiows how the mass of the HCf£(aq) changes with time. 4 20 S (3) = ‘%5 12,7 n wn ij = Time(s) 7.1 Define the term limiting reagent. (2) 7.2 Write down the name or formula of the limiting reagent in the above reaction. (2) 7.3. Calculate the: (1) 7.3.1 Percentage purity of the calcium carbonate. (6) 7.3.2 Maximum volume of CO2(g) produced at STP (4) In another reaction, X g of the SAME IMPURE CaCOs is now reacted with excess HCE. 7.3.3 Calculate the mass of the impure CaCOs that must be used to produce 12,6 g of H20. (5) [20] Copyright reserved Please turn over

Physicsuvmteneded from Stanmorephysics.com November 2023 Examination NS Downloaded from hlayiso.com QUESTION 8 (Start on a new page.) 8.1 8.2 8.3 8.4 8.5 Copyright reserved Oxalic acid ionizes in water according to the following balanced equation: C2O4(aq) + 2 H2O0(2) = C204 (aq) + 2 H30*(aq) 8.1.1 an acid according to the Arrhenius theory. 8.1.2 ite: down the formula of the TWO BASES in this reaction. Sulphuric acid, H2SOs, ionizes in TWO steps as follows: STEP [ H2SO4(aq) + H20(2) — HSO;(aq) + Hs0*(aq) STEP Il: HSO;(aq) + H20(t) > SO2 (aq) + HsO0*(aq) N E or FORMULA of the substance that acts as an ampholyte 5. Give a reason for the answer. es according to the following equation: HF(aq) = H* (aq) + F (aq) When a 0,10 mol.dm* solution of HF is prepared, it is found that the concentration of the F- ions at 25 °C is 0,018 mol.dm*. ls HF a strong acid? Choose from YES or NO. Give a reason for the answer. The salt sodium ethanoate (CHsCOONa) is formed when a weak acid reacts with a strong base. Write a balanced chemical equation for the neutralisation reaction between an acid and a base that will form CHsCOONa. HBr(aq) reacts with Zn(OH)2 according to the following balanced equation: Zn(OH)2(s) + 2HBr(aq) — ZnBra(aq) + 2 H2O0(t) X grams of pure Zn(Oh)2(s) is reacted with 90 cm? of HBr(aq) of concentration 0,45 mol.dm*. The excess HBr(aq) is then completely neutralised by 16,5 cm? of NaOH(aq) of concentration 0,5 mol.dm’, according to the following balanced equation: HBr(aq) + NaOH — NaBr(aq) + H2O(£) Calculate X. (2) (2) (3) (3) (3) (9) [22] Please turn over

Downloaded from hlayiso.com Physicsuentoneded from Stanmorephysics.com November 2023 Examination QUESTION 9 (Start on a new page.) The reaction between potassium permanganate (KMnOs) and hydrogen sulphide(H2S) in an acidic medium is given below. DO Ou! + H2S + HCL > KC£ + MnCk + S + H20 9.1 Define the te¢m oxidation in terms of electron transfer. (2) KM 9.2 Write down the: 9.2.1. Name or formula of the reducing agent. Explain the answer by referring to the oxidation numbers. (2) 9.2.2 Name or formula of the substance that is reduced. (1) 9.2.3. Reduction half reaction. (2) 9.2.4 Oxidation half reaction. (2) 9.2.5 Balanced net ionic equation. (3) [12] TOTAL: 150 Copyright reserved Please turn over

Downloaded from hlayiso.com Physicsuentoneded from Stanmorepbysics.com November 2023 Examination DATA FOR PHYSICAL SCIENCES GRADE 11 PAPER 2 (CHEMISTRY) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 11 VRAESTEL 2 (CHEMIE) TABLE 1: pss CONSTANTSITABEL 1: FISIESE KONSTANTES re NAME/NAAM SYMBOL/SIMBOOL VALUE/WAARDE Standard pressure 0 5 Standaarddruk P Linen ee” Pe Molar gas volume at STP Snr Molére gasvolume by STD Vm 22,4'dm"-mot Standard temperature 6 Standaardtemperatuur T 273K Charge on electron . 19 Lading op electron E 1.6 x.10'C Avogadro's constant 23 marl Avogadro-konstante Na G02s 1D net TABLE 2: FORMULAE/TABEL 2: FORMULES m n=— n=— M Na call or/of c= n ms V MV Vi, CaVa _ Mg CV, 7 ny Copyright reserved Please turn over

Downloaded from hlayiso.com PhysicDaumionedled from Stanmorephysics.com 2 TABLE 3: THE PERIODIC TABLE OF ELEMENTS November 2023 Examination 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 (I) (II) (ill) (IV) (Vv) (VI) (vil) (vIn) Atomic number a 1 KEY/SLEUTEL Atoomgetal 2 a H He 1 29 4 3 4 Electronegativity __ | ® Cu <_Symbol 5 6 7 8 9 10 & Li |3 Be Elektronegatiwiteit “| 4 ir Simbool S Bs Nile $ Ne 7 9 : 11 12 14 16 19 20 11 12 tf 13 14 15 16 17 18 2 Na/$ Mg Approximate relative atomic mass 2A)? Sild P iS =C@| Ar 23 24 Benaderde relatiewe atoommassa 27 28 31 32 35,5 40 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 S = Ca|% Se /3 Ti |S V |S Cr |SMn/& Fe |3 Co|S Ni |S Cu|3 Zn |S Ga|S Ge |S As |S Se/§ 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 6 Rb/S Sr iS Y |S Zr) Nb|/SMo/3 Tc\s Ru|s Rh |X Pd |G Ag |S Cd/5 In |S Sn/3Sb/s Te |G | 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 S Cs|$ Ba| La|S$ Hf| Ta} W)| Re| Os| Ir| Pt) Au| Hg|3 T@ |S Pb/3 Bi |S Po/s At) Rn 133 137 139 179 181 184 186 190 192 195 197 201 204 207 209 87 88 89 Lt a 3 Fr js Ra Ac 58 59 60 61 62 63 64 65 66 67 68 69 70 71 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 Copyright reserved Please turn over

Physical sciencesPAVQWNIOaded fronrhtayise:com lity/Toenemende oksiderende vermoé bi ing oxidising a Increas' Increasing reducing ability/Toenemende reduserende vermoé 4k: TENTIALS Downloaded Sth SNP EN et Half-reactions/Halfreaksies E° (v) Fo(g)+2e = 2F- + 2,87 Co*#+e = Co* +1,81 H202+ 2H*+2e° = 2H20 +1,77 MnO, +8H*+5e = Mn**+4H20 +1,51 Chk(g)+2e = 2Ch + 1,36 CrO? +14Ht+6e = 2Cr*+7H2O | +1,33 O2(g)+4H*+4e- = 2H20 +1,23 MnOz2+ 4H*+2e- = = Mn?* + 2H20 + 1,23 Pt}+2e = Pt +1,20 Bro(t)+2e° = = 2Br +1,07 NO3 +4H*+3e- = NO(g) +2H20 + 0,96 Hg?*+2e = H(t) +0,85 Agt +e Ag + 0,80 NO3 +2H*+e = NO2g)+H2O0 +0,80 Fe*+e = Fe +0,77 O2(g) + 2H* + 2e- == H2O02 + 0,68 la+2e = 2b +0,54 Cut +e Cu + 0,52 SO2+4H*+4e- = S+2H20 +0,45 2H20+O2+4e = 4OH™ +0,40 Cu*+2e = Cu + 0,34 SO% +4H'+2e- = SO2(g)+2H20 | +0,17 Cu%*+e- = Cu’ + 0,16 Sn*+2e = Sn +0,15 S+2H*+2e = HeS(g) +0,14 2H*+2e- = Ha(g) 0,00 Fe +3e- = Fe — 0,06 Pb**+2e- = Pb —0,13 Sn’ +2e = Sn -0,14 Ni#*+2e = Ni -0,27 Co*+2e = Co — 0,28 Cd*+2e = Cd -0,40 cet+e = Crt —0,41 Fe?++2e = Fe — 0,44 Cr++3e = Cr -0,74 Zn*+2e = Zn — 0,76 2H20+2e = H2(g) + 20H - 0,83 Cr++2e = Cr -0,91 Mn** + 2e- Mn -1,18 AG@t+3e = AL - 1,66 Mg**+2e = Mg — 2,36 Nat+e = Na -2,71 a’t+2e = Ca — 2,87 Sr2* + 2e- Sr — 2,89 Ba%*+2e = Ba — 2,90 Cs*+e = Cs - 2,92 K'te = K ~ 2,93 Lit+e Li — 3,05 Copyright reserved Please turn over

Physical Sciences\PA DOWVNIOAded fro mhia yi S OOOH Examination Downloaded $f42 48.G/ANOARPREDUER NB TeNTIALS TABEL 4B: STANDAARD-REDUKSIEPOTENSIALE Half-reactions/Halfreaksies £e (Vv) Lite = Li — 3,05 Ktte = K — 2,93 Cst+e = Cs — 2,92 Ba*+2e = Ba — 2,90 Ssr*+2e = Sr — 2,89 Ca*+2e = Ca — 2,87 Na*+e = Na -2,71 Mg**+2e = Mg — 2,36 AG++3e = AL — 1,66 Mn**+2e- = Mn -1,18 Cr++2e- = Cr — 0,91 2H20 +2e- = Ha(g) + 20H ~ 0,83 Zn*+2e = Zn — 0,76 cr++3e = Cr —0,74 Fe**+2e = Fe —0,44 Cette = Crt -0,41 Cd**+2e = Cd 0,40 Co*+2e = Co — 0,28 Ni#*+2e = Ni -0,27 Sn**+2e = Sn — 0,14 Pb**+2e- = Pb -—0,13 Fe*+3e = Fe — 0,06 2H*+2e- = Hag) 0,00 S+2H*+2e = H2S(g) +0,14 Sn*+2e = Sn? +0,15 Cu*+e- = Cut + 0,16 S02 +4H++2e- = SO2(g)+2H20| +0,17 Cu**+2e = Cu + 0,34 2H20+O2+4e = 40H +0,40 SQ2+4H*+4e° = S+2H20 +0,45 Cuv+e = Cu +0,52 k+2e = 2 +0,54 O2(g) + 2H* + 2e° == H202 + 0,68 Fe+e = Fe +0,77 NO3+2H*+e = NO2(g) +H20 + 0,80 Agite = Ag +0,80 Hg**+2e = Hg(t) +0,85 O53 +4H*+3e = NO(g) +2H20 + 0,96 Bro(t)+2e = = 2Br +1,07 Ptt+2e = Pt +1,20 MnO2+ 4H*+2e- = = Mn?* + 2H20 +1,23 O2(g) + 4H*+4e° = 2H20 +1,23 Cr? +14H++6e = 2Cr*+7H2O | +1,33 Ck(g)+2e° = 2Ch + 1,36 MnO, +8H*+5e = = Mn**+4H20 +1,51 H202+2H*+2e = 2H20 +1,77 Copyright reserved

Physical SciencesPA QW NIoaded fre mhia y |S Ov 14HR2 Examination Downloaded “pn Stanmorephysics. com F(g) +2e- =F +1,81 + 2,87 Increasing oxidising ability/ Toenemende oksiderende vermoé Increasing reducing ability/Toenemende reduserende vermoé Copyright reserved

Downloaded from hlayiso.com Downloaded from Stanmorephysics.com } KWAZULU-NATAL PROVINCE EDUCATION REPUBLIC OF SOUTH AFRICA NATIONAL SENIOR CERTIFICATE GRADE 11 This marking guideline consists of 7 pages. Copyright reserved Please turn over

Downloaded from hlayiso.com Physicsawrtemeled From Stanmorephyséespacees examination QUESTION 1: MULTIPLE-CHOICE QUESTIONS 11 Cv¥v 12 Dvv 13 BYY 1.4 Accept all optionsy ¥ 15 Dv¥v 16 AVY 17 AVY 18 Cvv 19 Cvv 1.10 Dvv QUESTION 2 2.1 A pair of electrons in the valence shell of an atom that is not shared with another atom. Vv 2:2:1 H v x@ v 20 3H ee 2.2.2 @ v Cle / 2.3.1 2v Zon 2h 2.4 O-FY The difference in electronegativity between O-F is greater than that between O-H/F has a higher electronegativity than H. vv 2.5 Angular/bentY 2.6 Dv Copyright reserved [20] (2) (2) (2) (1) (1) (3) (1) ()) Please turn over

Downloaded from hlayiso.com PhysicDsuwntended from Stanmorephysi 2021 Preparatory Examination ese we 2.7 NHs has polar molecules with hydrogen bonds/dipole-dipole forces and H2O has polar molecules with hydrogen bonds/dipole-dipole forces. v Forces are of the same order/comparable strengths. v OR Both molecules are polar / The strengths of the dipoles are of the same order/com le. v Polar sol ssolve in polar solvents / Like dissolves in likev (2) 2.8 2.8.1 Theaverage distance between the nuclei of two bonded atoms. v Vv (2) 2.8.2 The N atom is bigger than the H atom, v resulting in a bigger distance between the N and C nuclei. (2) 28.3 3Vvv (2) [21] QUESTION 3 (Start on a new page.) 3.1 The temperature at which the vapour pressure of a substance equals atmospheric pressure. VV (2) 3.2 Boiling point. ¥ (1) 3.3 3.3.1. Dipole- dipole forces v (1) 3.3.2 Hydrogen bondingY (1) 3.4. Less than’ (1) 3.5 Hydrogen bonding between H2O molecules is stronger than the dipole-dipole forces between H2S molecules. v More energy is required to overcome the intermolecular forces between water molecules. v (2) 3.6 Greater thanv Se is a bigger atom than Sulphurv (therefore forming a stronger dipole). (2) 3.7. LESS THAN. ¥ NHs molecules have one site for hydrogen bonding, while H2O molecules have two sites for hydrogen bonding. “ The intermolecular forces between molecules of NHs are weakerv than that between molecules of HzO Less energy will therefore be required to overcome the intermolecular forces in NH3. ¥ (4) [14] Copyright reserved

Downloaded from hlayiso.com Physicsuentoneded from Stanmorephysicsxcone 2021 Preparatory Examination QUESTION 4 (Start on a new page.) 4.1.1 Boyle’s Law”. The pressure exerted by a fixed quantity of gas is inversely proportional to the volume occupied by the gasv at constant te ture. v Li 4.1.2 Tempeératurev Mi of gas/number of moles of gas” — 4.1.3 pressurev 4.1.4 The gradient of the graph is the product of pressure and volume” According to the table the product of pressure and volume is a constantv Thus yielding a constant gradientY 4.1.5 piVi = peV2 (60)(50) = (D)(35) w D = 85,71 kPa v 4.2 4.2.1 Av 4.2.2 High pressure vv 4.2.3 The volume of the molecules of the gas and the intermolecular forces influence the measured valuev Causing it to be greater than the theoretical valuev Forces of repulsion between the gas particles prevents them from moving closer. ¥ QUESTION 5 (Start on a new page) 5.1 EXOTHERMIC. v The energy of the products is less than the energy of reactants/energy was releasedv 52 Hp - Hr v 109,2 - 351 v - 241,8 kJ.moltv AH 5.3. The unstable transition state from reactants to productsv ¥ Copyright reserved (3) (2) (1) (3) (2) (1) (2) (3) [17] (2) (3) (2)

Downloaded from hlayiso.com PhysicDsuewteneded from Stanmorephysicswcone 2021 Preparatory Examination 5.4 > Course of Reaction Marking guidelines/Nasienriglyne: Axes correctly labelled v Energy of Reactants correctly indicated. v Energy of Products correctly indicated. v Energy of Activated complex correctly indicated | Vv Correct shape as shown. v (5) 5.5.1 241,8 kJ.moltv (1) 5.5.2 1611,8 kJ.moltvv (2) [15] QUESTION 6 6.1 Simplest (whole number) ratio in which the atoms have combined. v ¥ (2) 6.2 N fe) % 30,4 69,6 Mass in 100g) 30,4 69,6 m 30,4 69,6 n = Mm v 14 16 = 2,17 =435 Vv R 1 2 v Empirical formula = NO2v (5) 6.3 N2O4vv (2) [9] Copyright reserved

Downloaded from hlayiso.com PhysicDsuewteneded from Stanmorephysicswcone 2021 Preparatory Examination QUESTION 7 7.1. The reagent that is used up completely in a reaction. vv (2) 7.2 Calcium carbonate/CaCOsv Vv (2) 7.3.1 ul COs) reacted = G )n(HCe) v 1\,m = (Sy) 1,,20-127, vv = Oss) v = 0,1 mol m(CaCOs) reacted = nM = (0,1)(100) v = 10g purty _ (40) x s00v 12,5 = 80% (7) 7.3.2 n(COz)produced n = == o 22,4 Vo= 2,24 dmsv (4) aa n(CacOs) = n(H20) ¥ n= ~ oM 18 = 0,7 mol m(CaCOz) = nM = (0,7)(100) v = 70g 80 = — XXv¥ a 100 X = 87,5g9v (5) [20] Copyright reserved

Downloaded from hlayiso.com Physicsuentoneded from Stanmorephysicsxcone 2021 Preparatory Examination QUESTION 8 (Start on a new page.) 8.1.1 An acid is a substance that produces hydrogen ions(H*)/hydronium ions(H3O*) when it dissolves in water. v Vv (2) nd C2047 V (2) 8.2 HSOj; Vv Actsias a base in step |, Y and as an acid in step Il (3) 8.3 NO. v The concentration of F- ions is lower than concentration of HF. ¥ HF lonises incompletelyY (3) 8.4 CHsCOOH + NaOH — CHsCOONa + H2O0 LHSY RHSv BalancingY (3) 8.5 cVY 90 0,45)( ——)v (0,45)( T0002 0,0405 mol.dm? n(NaOk) ¥ (ratio) cV 165 0,5)( —~ jv KO.EX 1000 8,25 x 10° mols n((Zn(OH)2) = 5 (HEN) Y (ratio) 5 (0.0405 - 8,25 x 103) vv 0.016125 mols nM (0.016125)(99) v 1,596375 g/ 1,6 gv n(HBr)initial n(HBr)excess iT) ul X = m((Zn(OH)2) Wow uw (9) [22] QUESTION 9 (Start on a new page.) 9.1 Oxidation is the loss of electronsv v (2) 9.2.1. Hydrogen sulphide/H2S/S*-Y S undergoes an increase in oxidation no.” (2) 9.2.2 Potassium permanganate/permanganate ion/KMnOa/MnOa/Mn7*v (1) 9.2.3 MnO« +8H*t +5e — Mn? + 4H20 vv (2) 9.2.4 HS + S + 2H* + 2evv (2) 9.25 2MnO, + 5H2S + 6H* > 2Mn*%* + 5S + 8H2O (3) (LHS V; RHS V ; Balanced correctly “) [12] TOTAL 150 Copyright reserved