Physical Sciences Grade 11 P2 September Test 2019 QP & Memo

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Downloaded from hlayiso,co Physical Science P2 eptember 2019 Gomman Test NSC INSTRUCTIONS AND INFORMATION TO CANDIDATES 1. Write your name on the ANSWER BOOK. 2. Answer ALL the questions in the answer book. 3. You may use a non-programmable calculator. 4. You may use appropriate mathematical instruments. 5. Number the answers correctly according to the numbering system used in this question paper. 6. YOU ARE ADVISED TO USE THE ATTACHED DATA SHEETS. 7. Give brief motivations, discussions, et cetera where required. 8. Show the formulae and substitutions in ALL calculations. 9. Round off FINAL answers to a minimum of TWO decimal places Copyright Reserved Please Turn Over

Downloaded from hlayiSO.COM re: 2019 common Test NSC Physical Science QUESTION 1: MULTIPLE- CHOICE QUESTIONS Four options are provided as possible answers to the following questions. Each question has only ONE correct answer. Write only the letter (A — D) next to the question number (1.1 ~ 1.10) in the ANSWER BOOK. E.g. 1.11 A 4.1. The measure of the tendency of an atom in a molecule to attract shared electrons is called ... A electronegativity B ionisation c mutual attraction D electronegativity difference (2) 1.2 Hl hasa higher boiling point than HCE. Which statement is INCORRECT for this observation? A The iodide ion is a larger ion than the chloride ion. B The molar mass of HI is greater than the molar mass of HC. Cc There are more electrons in HI than HC?. D Hydrogen bonding is present in HI. (2) 1.3. Solid X has a low melting point and dissolves easily in a non-polar solvent. Solid Y has a high melting point and dissolves easily in a polar solvent. Solids X and Y are ... Solid X Solid ¥ A |HeO la Bk KCE Cc _| Nace KBr Do c = (2) 1.4. Which ONE of the following solutions contains the GREATEST number of dissolved ions? A 50 cm* of a 0,10 mol-dm® LiF B 100 cm? of a 0,20 mol-dm* KC2 C 100 cm? of a 0,10 mol-dm® MgCl D 50 cm? of a 0,20 mol-dm? NazO (2) 1.5 | When the VOLUME of a given mass of gas is DOUBLED at constant temperature, the PRESSURE is HALVED. Which ONE of the following statements BEST explains this observation? A The force of attraction between the gas molecules is halved. B The kinetic energy of the gas molecules is halved. Cc The number of collisions per unit time between the gas molecules and the walls of the container is halved. D The speed of the gas molecules is halved. (2) Copyright Reserved Please Turn Over

Physical Sciencer2 «© DOWNIOAdE from hlayiSQ,GOIM common tes NSC 1.6 Which graph correctly shows how a real gas will deviate from ideal gas behaviour? C T D7, | P V (2) 1.7. Activation energy can be BEST described as ... A energy of the reactants before a reaction takes place. B kinetic energy needed for a reaction to take place. Cc difference in energy between reactants and products. D heat of a reaction. (2) 1.8 | Consider the following acid base reactions: NHsg (g) + HeO(2), — NH,*(aq) + OH (aq) $0.7 (aq) + HNO3(aq) > HSO,4 (aq) + NOs (aq) Two substances acting as PROTON DONORS in the above reactions are: HO and SO,” NH; and SO,” NH3 and HNO3 H2O and HNO; (2) VDOULY 1.9. Which ONE of the statements concerning a REDOX reaction is CORRECT? The oxidising agent loses electrons. The number of electrons lost must equal the number of electrons gained. There is no change in the oxidation states of the substances. It involves a change in a mass of the system. (2) OOoO> 1.10 In which ONE of the following pairs of substances is the oxidation number of sulphur the same? Cc H2S and S D SOx and HeSO3 (2) [20] Copyright Reserved Please Turn Over

Consider the following list of substances and answer the questions that follow. | enya! Slence Downloaded from hlayisO.CQM. .. 201s common Te! | QUESTION 2 | 2.1 State the definition of a covalent bond. (2) | | HF BC@, CF, NH; CO, SCe | 2.2 From the list write down the formula/e of: \ 2.2.1 the molecule that has an octahedral shape (1) \ : 2.2.2 asubstance that can sublime at room temperature (1) | 2.2.3. the compound that is MOST POLAR (1) | | 2.2.4 TWO substances that have hydrogen bonds between their molecules (2) 2.3 BCf, can form a dative covalent bond with NHs3. 2.3.1 Draw the Lewis structure for the BC2s molecule. (2) 2.3.2 What is the shape of the BCfz molecule? (1) 2.3.3 Explain why NH is able to form a dative covalent bond with BCfy. (2) 2.4 Explain why the bonds in CF, are polar, but the molecule is non-polar. (3) ! [15] | | | Copyright Reserved Please Turn Over

Physical Science P2 QUESTION 3 NSC Down loaded from h layisg,com, Ccmmon Test The table below shows the relative molecular masses, melting points and boiling points of a few substances. 3.1 3.2 3.3 Relative Substance Formula | molecular mass Me me. Bolling point (g-mot") point("c) | (°C) Propane CgHg 44 —188 -42 Butane CaHio 58 —138 -1 Pentane Cs5H 42 72 ~130 36 Haptane CrHi6 100 ~90,5 98,4 Define melting point. From the substances in the table, write down the NAME or FORMULA of: 3.2.1 TWO substances that are LIQUIDS at room temperature. 3.2.2 The substance with the HIGHEST vapour pressure. 3.2.3 ONE substance that is a GAS at room temperature. Propane, butane, pentane and heptane are non-polar molecules. 3.3.1 Name the type of Van der Waals forces present between these molecules. 3.3.2 State the trend with respect to the boiling points of these compounds as shown in the table. 3.3.3 Explain the answer to question 3.3.2 by referring to the strengths of the forces and the energies involved. Copyright Reserved (2) [14] Please Turn Over

Physical Science P2 QUESTION 4 Downloaded from hlayiso. NSC 4.1. Consider the following table of bond length and bond energies. com September 2019 Common Test C=C 134 614 c-C 154 347 cl- Ce 199 242 I-] 266 151 4.1.1 State the definition of bond length. Use the information in the table to answer the following questions. 4.1.2. What is the relationship between bond energy and bond length in a stable molecule? 4.1.3 Explain the relationship referred to in question 4.1.2. 4.1.4 Consider the C = C bond. How will the bond energy of C = C compare to that of C = C? Choose from GREATER THAN, LESS THAN or EQUAL TO. Give a reason for the answer. Copyright Reserved (2) (1) (2) Please Turn Over

Downloaded from hlayiso.com Physical Science P2 September 2019 Common Test NSC 4.2 Use the tabie of bond energies below to answer the questions that follow. Bond Bond energy (kJ-mol") H-H 436 C-H 413 Ct- Ce 242 C-CL 327 H-Ce 431 Methane reacts with chlorine according to the following balanced equation: H H | Jl, Ch = H—— C — ce + HCe 4.2.1 Calculate the heat of reaction (AH) for the above reaction. (4) 4.2.2 \s the reaction EXOTHERMIC or ENDOTHERMIC? Give a reason for the answer. (2) 4.2.3 Sketch a potential energy vs course of reaction graph for this reaction. On the graph indicate the: Energy of the reactants Energy of the products Heat of reaction, and Activation energy. (5) [18] eoeee QUESTION 5 5.1 Nitrogen and oxygen form a series of oxides with the general formula N,Oy. One of these compounds contains 36,80% nitrogen and 63,20% oxygen. Determine the empirical formula of this compound. (5) 5.2 Calculate the mass (in grams) of nitrogen present in 10 g of ammonium nitrate (NH4NOs). (3) Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Physical Science P2 September 2019 Common Test NSC QUESTION 6 An investigation is carried out to determine the relationship between the pressure and temperature of an enclosed gas. The following results were obtained from the investigation. Pressure (kPa) Temperature (°C) 100 -151 200 -29 300 93 400 Xx 6.1. Name the gas law being investigated. (1) 6.2 Name TWO variables that need to be controlled in this investigation. (2) 6.3 State the definition of temperature. (2) 6.4. __ Use the graph sheet provided (at the back of this question paper) to draw the graph of Pressure (in kPa) versus Temperature (in °C). The values indicated on the axes have been measured to scale. (2) (HAND IN THE GRAPH SHEET TOGETHER WITH YOUR ANSWER BOOKLET), 6.5 Extrapolate (extend) the graph until it cuts the x axis. 6.5.1. What is the value of the Kelvin temperature when the pressure is zero? ~—(1) 6.5.2 What is this temperature called? (1) 6.6 Use the graph to write a conclusion for the above investigation. (2) 6.7 Determine the value of X in the table. (4) 6.8 How will the gradient of the graph be affected if a GREATER MASS of the gas is used? Choose from: INCREASE, DECREASE or REMAIN THE SAME. Explain the answer. (4) [19] Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Physical Science P2 September 2019 Common Test NSC QUESTION 7 A sample of chalk containing 95% calcium carbonate (CaCOs) was reacted with excess dilute hydrochloric acid and 2,128 dm* of carbon dioxide was collected at STP according to the following balanced reaction. CaCOs (s) + 2HCE (aq) > CaCe, (aq) + HzO (€) + CO: (g) 7.1 Define an acid according to the Arrhenius Theory. (2) 7.2 Why is HC? considered a strong acid? (2) 7.3. Write down the ionisation reaction of HC£ in water. (2) 7.4 Calculate the mass of the sample of chalk used. (6) 7.5 The excess hydrochloric acid is neutralised by adding sodium carbonate. Write a balance equation for the reaction between hydrochloric acid and sodium carbonate. (3) [15] QUESTION 8 Candle wax burns in oxygen to form carbon dioxide and water according to the following balanced equation: CosHag +35 Or > 23 CO, +24 H20 In one such reaction 4,816 x 10” molecules of candlewax reacts with 3 moles of oxygen. 8.1 Define LIMITING REAGENT. (2) 8.2 Determine which of candte wax or oxygen is the limiting reagent. (4) 8.3. Calculate the MAXIMUM mass of water that can be produced. (4) 8.4 _ It is found that the percentage yield of carbon dioxide is 90%. 8.4.1 Calculate the ACTUAL volume of CO, collected if the molar volume of the gas is 23,2 dm* at 27°C. (4) 8.4.2 Caiculate the pressure that this gas will exert ata temperature of 27°C. (4) [18] Copyright Reserved Please Turn Over

Physical Science P2 Downloaded from hlayiso.com NSC QUESTION 9 Grade 114 learners want to prepare a standard solution of oxalic acid (H2C2Ox). They use 15,75 g of hydrated oxalic acid crystals (HeC204-2H20) in order to make ' a solution of concentration 0,5 mol. dm. They, prepare the solution in a volumetric flask. They have 250 cm®, 500 cm’ and 1 dm volumetric flasks available. September 2019 Common Test ‘ 9.1. Define concentration. (2) 9.2. Which volumetric flask should they use? | (Show by calculation how you arrived at the answer) (4) | 9.3 The learners wish to change the concentration of a smail amount of this acid i to 0,2 mol.dm®. To do this they place 25 om* of the acid in a beaker and ! add water to it. How much water must be added to the acid to give the required concentration of 0,2 mol.dm*? (4) 9.4 The standard oxalic acid solution is used to titrate a solution of sodium ! hydroxide. 9.4.1 Write a balanced equation for the reaction taking place here. (3) 9.4.2 Which indicator should they use for this titration? Choose from BROMOTHYMOL BLUE, PHENOLPTHALIEN or METHYL ORANGE. Explain the answer. (3) : [16] ' QUESTION 10 Study the reaction below: Mg(s) + 12(8) > Mg* (aq) + 1 (aq) : 10.1 Define REDUCING AGENT in terms of oxidation numbers. (2) : 10.2 Identify the reducing agent in the above reaction. (1) 10.3 Write down the FORMULA of the substance that is reduced. (1) 10.4 Write down the balanced for: | 10.4.1 the oxidation half reaction. (2) | 10.4.2 the reduction half reaction. (2) 10.4.3 the overall reaction. (2) [10] TOTAL: 150 I Copyright Reserved

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Downloaded from hlayiso.com September 2019 Common Test Physical science P2 DATA FOR PHYSICAL SCIENCES GRADE 11 PAPER 2 (CHEMISTRY) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 117 VRAESTEL 2 (CHEMIE) TABLE 1: PHYSICAL CONSTANTS/TABEL 1: FISIESE KONSTANTES NAME/NAAM SYMBOL/SIMBOOL | VALUE/WAARDE TABLE 2: FORMULAE/TABEL 2: FORMULES Pi Pa pV=nRT nal aN M Na nm “a ORJOF cot Copyright Reserved Please Turn Over

Physical science P2 lity/Toenemende oksiderende vermoé ing abi dis i OXi Increasin Copyright Reserved Downloaded from hlayiso.com September 2019 Common Test TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD-REDUKSIEPOTENSIALE so§ +4H!' 4 2e Cw $e 2HO +O; + de SO: + 4H! + de Cubte Ty + 2c Oxy) + It 4 Qe Fe" ee NO, +2H +e Agite Hy" + 2e NO, +4H" +e Br3(t) + 2e POi42e MnO;+ 4H! + Ong) + 4H + do oof + 14H" + Ge Chg) + Je MnO g + 8H" + Se 1,0) + 2H +2e Cote F(a) + 2e Half-reactions/Halfreaksies fo (V) litte 2 Li Kr+e ou K Cite om Cs P+ 2e me Ba Srh42e Sr Ca 420 2 Ca Nate 2 Na Mg +2. 2 Me AU 4 3e AC Mn** + 2e Mn Crt + 20 Cr 2H,0 + 2e ss Hugo + 20H zn +e mm Crts3e0 2 Cr Fol + 2e Be Cree 2 Cu" 4 20 Com + 2e Co Ni! + 2c Ni So ¢2e 0 Sn Pb? + 2v Pb - 013 Fe 3e0 a Pe 0.06 2H +2c7 = Mhiph 0,00 S+ 2H? +2 HS(g) + O14 Sn’ 420 = Sn! +015 Cute ou Cu +016 SOstg) + 2HLO | 40,17 Cu +034 4OH + 0.40, $+ 2H,0 + 045 cu +0152 21 +054 HO, + 0.68 Feet +077 NOs{g) + HO + 0.80 Ag + 0.80 He) + O85 NOW) + 2H,0 +096 2B +107 Pt + 1,20 Mn°* + 2H.O #123 bo 2Cr* + 7H.0 21 Mn™* + 41,0 2H:0 Co 2F Increasing reducing ability/Toenemende reduserende vermoé Please Turn Over

Downloaded from hlayiso.com Physical science P2 September 2019 Common Test | NAME: | GRADE: 11 GRAPH SHEET FOR QUERSTION 6.4 (HAND IN THIS SHEET TOGETHER WITH YOUR ANSWER BOOKLET). GRAPH OF PRESSURE VERSUS TEMPERATURE p(inkPa) 4 i 1300 —|200 — 100 v -151 -29 93 T (in °C) Copyright Reserved

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Downloaded from hlayiso.com September 2019 Common Test WSC Guideline 4 subsiance that gen/hydronium ions (H30*) water ¥v 0?) di lonises completely in water ¥ Q) av 4 Ch + Hore (2) + 0,083 mol. et CO2z Ww y cos* 0,095mol (6) reactants” producis’ balancingY = (3} {13} served Please Turn Over Physical Sciences P2 8 NSC - Merking Guideline September 2019 Common Test QUESTION 3 8.1 The substance that is used up completely in a reaction v ¥ (2) 8.2 Ne ‘of moles™: = "| Casas) Oz =| 20. Ratio. 1 36 24 Start 0,08 3 0 0 Change 0,08” 2,80V 4,84 1,92 End _ O20 1,84 1192 Candle wax is the limiting reagent. ¥ oR Candlewax: n= Nia = 4,816 x 107 /6,022 x 107 v = 0,08mol “ CosHas : O2 1:35 Noz needed is 2,80mol v Limiting reagent is candiewax ~ (4) 8.3 POSITIVE MARKING FROM 3.2 From table: n zo formed = 1,92 mol ““ n=mM 1,92 = m/i8v m = 34,569” OR Castles > H20 4:24 v nH20 = 0.08 x 24 = 1.92mol” n=miM 4.92 =m/18v m = 34,569” (4) Copyright Reserved Please Turn Over

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4.23 ¥ Shape ¥ energy of reactants correctly indicated “energy of products conactly indicated ¥ AH indicated correctly ¥ activation energy correctly indicated Physical Sciences P2 3 September 2019 Common Test Physical Sciences P2 4 September 2019 Common Test NSC = Marking Guideline NSC - Marking Guideline QUESTION 3 QUESTION 4 3.1 The temperature at which the solid and liquid phases of a substance are at 41 equilibriumy ” ?) 4.1.1 The average distance hetween the nuclei of bonded atoms. @) 32 . 4.1.2 The shorter the bond length, the greater the bond energy. (1) = 3.2.1 Heptane (C7) “ Pentane(CsH:2) “ (2) re) 4.1.3 Bonds with a shorter bond fength have greater forces of attraction’ and oO 3.2.2 Propane (CsHa) ~ (1) require more energy to break the bond.” (2) ° {o) 3.2.3 Propane (CaHs) or Butane (CaH19) “ (t) 4.1.4 GREATER THAN. “ C=C has triple bond, ¥ more energy needed to break ” the bonds. (2) —_ > 33 42 qv] 3.3.1 Landon Forces / Induced dipole “ (1) 42 1 _ e Energy absorbed = 4(413) + 2427 x ome 3.3.2 As the molecular mass of the substance increases -’, the boiling Eneray released : Ban oe 397 + 434 point increases. ¥ (2) i = 1997kJ = . AH = 1894 - 1997” ro) 333 = 103 ki.mot' rae * With increase in molecular mass there is an increase in strength (pee of the forces Oo « More energy needed to separate moiecules ¥ (2) 4.2.2 Exothermic “ AH < 0/ More energy is released than absorbed.” (2) ® m 2 (5) (18) Copyright Reserved Please Tum Over Copyright Reserved Please Tum Over