Physical Sciences Grade 12 P2 Gauteng Mock 2019 QP

Downloaded from hlayiso.com ¥ > GAUTENG PROVINCE — REPUBLIC OF SOUTI AFRICA . & la Sa GAUTENG DEPARTMENT OF EDUCATION PREPARATORY EXAMINATION 2019 10842 PHYSICAL SCIENCES: CHEMISTRY PAPER 2 TIME: 3 hours MARKS: 150 16 pages + 4 data sheets and 1 answer sheet PHYSICAL SCIENCES: Paper 2 NAN 10842E X10 Mun P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 2 (PAPER 2) 10842/19 GAUTENG DEPARTMENT OF EDUCATION PREPARATORY EXAMINATION PHYSICAL SCIENCES: CHEMISTRY (Paper 2) TIME: 3 hours MARKS: 150 INSTRUCTIONS AND INFORMATION 1. 2. 10. 11. 12. Write your name in the appropriate space on the ANSWER BOOK. This question paper consists of 10 questions. Answer ALL the questions in the ANSWER BOOK. Start the answer to each question on a NEW page. Number the answers correctly according to the numbering system used in this question paper. Leave ONE line open between sub-questions, for example, between Question 2.1 and Question 2.2. You may use a non-programmable calculator. You may use appropriate mathematical instruments. You are advised to use the attached DATA SHEETS. Show ALL formulae and substitutions in ALL calculations. Round-off your final numerical answers to a minimum of TWO decimal places. Give brief discussions, et cetera where required. Write neatly and legibly. P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 3 (PAPER 2) 10842/19 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Four options are given 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. 1.1. Which ONE of the following is the correct structural formula for 1,2,2-trichloropropane? aA ual Bey H—C—C—C—Cl ci—G—C—Cl-G-H | cl H H H Ci H cet ae ao mo i cl Cl Cl cl H Cl (2) 4.2 Which ONE of the following pairs of compounds contains members of the same homologous series? A CoH, and C3Hs B C3He and C4Hs Cc CH,O and C2H,02 D = C2H4O and C3HeO (2) 1.3. Consider the following structural formula of an organic compound and the statements referring to it. iia. i H—C—C—C—C-H H-C-H tot od H H H H | H-C—-C—C-H (rn H H H I. The compound belongs to the same homologous series as methane. Il. The compound is a hydrocarbon. Ul. The compound has a higher boiling point than methane. Which of the above statements are correct? A Only I B band Il Cc Il and III D I, Wand Ill (2) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY (PAPER 2) 10842/19 1.4 The following equation represents the chemical reaction of the dissociation of pure distilled water: 1.5 1.6 H2O = H*(aq) + OH (aq) AH >0 How will the pH and the acid-base properties of distilled water be affected if the temperature of the water is increased? 00 WO > pH Acid-base properties Decreases Becomes acid Decreases Remains neutral Remains the same Remains neutral Increases Becomes alkaline A standard zinc / copper cell is set up with a salt bridge containing a concentrated potassium nitrate (KNOs3) solution. The electrolytes are zinc sulphate (ZnSO.) and copper sulphate (CuSQ,). After the reaction has been allowed to continue for an extended period of time, the salt bridge was found to contain ... A B c D K* and NO; ions. K*, NO; and SO ions. K*, NO; and Zn”* ions. K*, NO;, SO? and Zn?” ions. The following reaction is given. HC,0;(aq) + H,0(¢) > H,O*(aq) + C,07 (aq) The correct conjugate acid-base pair is given as: A B HC,0; (aq) and H,O(e ) HCO; (aq) and H,0* (aq) HC,07 (aq) and C,07° H,O(é) and C,0% (aq) (aq) (2) (2) P.T.O.

1.7 1.8 Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 5 (PAPER 2) 10842/19 The equilibrium constant for the gas phase reaction given below is 230 at 300°C. 2NHa(g) = 3H2(g) + Na(g) Which one of the following statements is true for this reaction at equilibrium? Only reactants are present. Only products are present. The concentration of reactants is high. 0 AQ BD F The yield of products is high. (2) Consider the following chemical reaction: CuO + HeSO4 > CuSO, + H20 In this reaction copper(II)oxide (CuO) acts as ... A abase. B anacid. C areducing agent. D an oxidising agent. (2) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 6 (PAPER 2) 10842/19 1.9 | The graph below shows the change in potential energy for the reaction: CO2+NO=CO+ NO, 35 fon} Ep (kJ.mol’) & ro) Reaction co-ordinate The activation energy in kJ-mot" for the reverse reaction is ... A B c D 35. 50. 85. 15. (2) 1.10 Which ONE of the following statements about the extraction process of aluminium is TRUE? A B Cc D The aluminium ion is oxidised. Aluminium forms at the anode. The aluminium oxide ore is called bauxite. Carbon dioxide gas forms at the cathode. (2) [20] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 7 (PAPER 2) 10842/19 QUESTION 2 (Start on a new page.) 2.1 Consider the condensed structural formulae of the organic compounds below. A H,C-———CH==CH,, B H3¢-—————CH OH HC: C——OH H3C C——O——CH Cc D | H3C CH CH, CH E F H3C ¢ CH OH OH Write down the letter that represents a substance that ... 2.1.1 is an unsaturated compound. (1) 2.12 willreact with a halogen by means of an addition reaction. (1) 2.1.3 can be used for the preparation of methyl ethanoate. (1) 2.1.4. is aprimary alcohol. (1) 2.1.5 when produced, needs sulphuric acid as a catalyst. (1) 2.2 Draw the structural formula of 2,4-dimethylhexan-3-one. (3) 2.3. Write down the correct IUPAC name of the following compound: LP ea TTT H F H H (3) [14] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY (PAPER 2) 10842/19 QUESTION 3 (Start on a new page.) 3.1 3.2 3.3 3.4 3.5 3.6 Write down the name of the homologous series to which each of the following compounds belong. 3.1.1. CsHi9O2 3.1.2. CHsCOCH3 3.2.1 Define the term chain isomer. 3.2.2. Write down the structural formula and IUPAC names of the 3 isomers of CaHs. The compound responsible for the fruity scent in pineapples, butyl pentanoate, is prepared in a laboratory. Write down the ... 3.3.1 IUPAC names of TWO compounds needed for this preparation. 3.3.2 type of reaction that takes place. The boiling points of two compounds are given below. Compound Boiling point, °C butyl pentanoate 185,8 butyl butanoate 166,0 Explain why the boiling point of butyl pentanoate is higher than that of butyl butanoate. Refer to relative strengths of intermolecular forces and energy. Explain the difference between addifion polymerisation and condensation polymerisation. Consider the structural formula of a part of a polymer as shown below. H aH | | C—¢ | | H HJy Write down the IUPAC name of ... 3.6.1 this polymer. 3.6.2 the monomer used to prepare this polymer. (1) (1) (2) (6) (2) (1) (3) (4) (1) (1) [22] P.T.O.

41 42 4.3 44 4.5 Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 9 (PAPER 2) 10842/19 QUESTION 4 (Start on a new page.) In the flow diagram below, X, Y and Z represent three different types of organic reactions. P represents an organic compound. CH; CHg | Reaction X HgC—CHp~ CHa“ Br ——_ HyC— CH) CH= CH; CH, . KOH(aq) Reaction Y Mild Heat Reaction Z P Name the type of reaction represented by X. (1) State TWO reaction conditions needed for reaction X. (2) Reaction Y represents a substitution reaction. Write down the structural formula of the organic compound P, formed in this reaction. (3) Apart from the organic reactant, write down the NAME or FORMULA of the other reactant needed in reaction Z. (1) Name the type of reaction represented by Z. (1) [8] P.T.O.

Downloaded from hlayiso.com QUESTION 5 (Start on a new page.) PHYSICAL SCIENCES: CHEMISTRY (PAPER 2) 10842/19 10 Copper(!I)carbonate reacts with diluted hydrochloric acid as given in the reaction below. CuCOs,(s) + 2HCf(aq) -> CuCea(aq) + H20(2) + CO2(g) A learner used the apparatus shown below. - Cotton-wool plug Conical flask 5 Diluted hydrochloric acid 4 A 9 Lumps of copper carbonate — —beoroo ooo) 165,00 g | « Chemical balance 5.1 Supply a reason why a cotton-wool plug is placed in the mouth of the conical flask. The experiment was carried out using a 0,50 g sample of pure copper(II)carbonate. The graph below shows the results obtained: Graph of mass versus time 165, 164,95 Mass (g) 164,90 164,85 164,80 5 io 30 40 50 60 Time (s) 5.2 For this sample of pure copper(Il)carbonate, calculate the average reaction rate, in g-s", for the first 10 seconds. (1) (3) P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 1 (PAPER 2) 10842/19 5.3 The experiment is repeated under the same conditions using a sample of 0,5 g of impure copper(Il)carbonate. The data obtained is given below. Time (s) 0 4 6 8 12 20 40 60 Trees (a) in | 465,00 | 164,90 | 164,88 | 164,87 | 164,86 | 164,85 | 164,85 | 164,85 5.3.1. Drawa line graph showing the change in mass of the impure copper(Il)carbonate versus the time. Use the attached ANSWER SHEET to answer this question. (3) 5.3.2 This experiment is repeated with hydrochloric acid that has been heated. Explain in terms of the collision theory how the rate of this reaction will be affected. (4) 5.4 Alearner performed three experiments in which zinc reacted with an excess of a 1 mol-dm® hydrochloric acid solution. In ALL three experiments, the leamer kept the initial temperature the same and used the same volume of a 1 mol-dm* hydrochloric acid solution. The graph below shows the results for each of the experiments 1, 2 and 3. 40- 2 Volume of 30) Hydrogen (cm?) 3 20-- 10-+- 0 __ Time (minutes) _ — _ _ | 5.4.1 In which experiment did the reaction take the longest to complete? Choose from 1, 2 or 3. (1) 5.4.2 Suggest ONE factor that could have been changed from experiment 1 to produce the results in experiment 2. (1) 5.4.3 1g of zinc was used in experiment 1. What mass of zinc was used in experiment 3? (No calculation required.) (1) [14] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 12 (PAPER 2) 10842/19 QUESTION 6 (Start on a new page.) Consider the following reversible reaction represented below in a closed container. H,(g) + la(g) = 2HI(g) Three experiments were done under different conditions as shown in the table below. In each case 0,5 mol Hz and 0,5 mol |p reacted in a 1 dm® container. GRAPH CONDITIONS A 500°C B 500°C; different condition from A ie} 600°C; same conditions as A The sketch graphs of the concentration versus time for the three experiments are shown below. Experiment A Experiment B Experiment C 0,5 4 05] 05+ Product -----y------ eee Product SS inte 0,38 Product < c co 4 N\.------ ee H £ a f Fe e 7, a Reactants 8 3 {-------2--- — BO jf. Qo : so ' Reactants 53 ' eaten |5 o \ of SE|/ : 8& 5 2 3 Time (min) Time (min) Time (min) 6.1 What condition changed in experiment B? (1) 6.2 Explain your answer to Question 6.1. (2) 6.3 Refer to the graphs of experiment A and C. Is the forward reaction ENDOTHERMIC or EXOTHERMIC? (1) 6.4 Use Le Chatelier’s principle and explain your answer to Question 6.3. (3) 6.5 At equilibrium, 0,3 mol-dm’? Hp is present in the container at a temperature of 500°C. Use the data given to calculate the equilibrium constant at 500°C. (6) 6.6 Will the K, value be HIGHER THAN, LOWER THAN or REMAIN THE SAME at a temperature of 600°C? (1) 6.7 _ Explain your answer to Question 6.6. (2) [16] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY (PAPER 2) 10842/19 13 QUESTION 7 (Start on a new page.) An electrochemical cell is set up as shown in the diagram below. 7.1 7.2 7.3 7.4 75 7.6 (v) LY Salt bridge [+ ch, Mn Pt Mn?*(aq) Cr (aq) Write down the values of the standard conditions that apply to the C&/Cf half-cell. For this cell, write down the equation for the ... 7.2.1. oxidation half reaction. 7.2.2 net reaction of the cell. Write down the cell notation for this cell. Write down the FORMULA of a possible electrolyte that can be used in the Mn/Mn** half-cell. Write down the NAME or FORMULA of the oxidising agent in this cell. Calculate the initial reading on the voltmeter when this cell functions under standard conditions. (3) (2) (3) (3) (1) (1) (3) [16] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 14 (PAPER 2) 10842/19 QUESTION 8 (Start on a new page.) The diagram below represents an electrochemical cell. The electrodes of the cell are labeled P and Q. 8.1 8.2 8.1.1 8.1.2 battery P Q Which electrode, P or Q, is the anode in this cell? (1) Give a reason for your answer to Question 8.1.1. (1) This cell is used to plate an iron coin with nickel. The iron coin is connected to a steel electrode while the other electrode is a nickel electrode. 8.2.1 8.2.2 8.2.3 8.2.4 8.2.5 8.2.6 Write down the FORMULA of the ION that can be used as an oxidising agent in this cell. (1) To which electrode, P or Q, is the iron coin attached? (1) At which electrode does reduction occur? Choose from P or Q. (1) Write down the half-reaction that will occur at the electrode mentioned in Question 8.2.3. (2) The anode of this cell is a nickel electrode. How does the concentration of the electrolyte change during the functioning of the cell? Write only INCREASES, DECREASES or REMAINS THE SAME. (1) Explain your answer to Question 8.2.5. (2) [10] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 15 (PAPER 2) 10842/19 QUESTION 9 (Start on a new page.) 9.1 9.2 Washing soda contains sodium carbonate (Na2CQs3) as its most important constituent. Learners used 5,13 g of the washing soda crystals to prepare a 250 cm? solution in distilled water. They titrated 25 cm? of the sodium carbonate solution with 36 om? of a 0,05 mol-dm H2SO, solution to neutralise the solution. The balanced equation for the reaction is: Na2COs(aq) + HeSOa(aq) > NazSO,(aq) + CO2(g) + H20(2) 9.1.1 Define an ampholyte. (2) 9.1.2 Identify which ONE of the compounds in the equation above CAN act as an ampholyte. (1) 9.1.3. Calculate the number of moles of sulphuric acid that reacted with the sodium carbonate. (3) 9.1.4 Calculate the mass of the sodium carbonate in the washing soda that was used and neutralised during the titration. (4) 9.1.5 Calculate the percentage purity of the washing soda sample. (3) When CO? ions are added to water, the concentration of the hydroxide ions present in the water increases. Write down a balanced equation for this reaction between CO} and H20. (2) [15] P.T.O.

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 16 (PAPER 2) 10842/19 QUESTION 10 (Start on a new page.) 10.1 A fertilizer bag is labelled 2:6:3 (40). 10.1.1. Explain the meaning of the value in brackets (40). (1) 10.1.2 Name any TWO primary nutrients that are contained in this fertiliser bag. (2) 10.1.3. Calculate the percentage mass of nitrogen in this fertiliser bag. (3) 10.2 Part of the flow diagram below shows the industrial process used in the production Fertiliser A of nitric acid. Process Y Sulphuric acid reacts with _| 10.2.1 Write down the NAME or FORMULA of Fertiliser A. (1) 10.2.2 Name the process used to make ammonia. (1) 10.2.3. Write down the FORMULA of Fertiliser B. (1) 10.2.4 Write down the NAME of process Y. (1) 10.2.5 Why is it important for fertilisers to be soluble in water? (1) 10.2.6 If too much fertiliser is used and it leaches into rivers, what negative effect could this have on rivers and dams? (1) 10.2.7 Name TWO reactants needed to produce ammonia. (2) 10.2.8 During the manufacturing of H2SO, sulphur is burned in air. NAME the product of this combustion reaction. (1) 10.2.9 Write down THREE positive impacts of fertilisers on humans. nel TOTAL: 150 END

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY (Paper 2) 10842/19 DATA FOR PHYSICAL SCIENCES GRADE 12 PAPER 2 (CHEMISTRY) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 12 VRAESTEL 2 (CHEMIE) TABLE 1: PHYSICAL CONSTANTS/TABEL 1: FISIESE KONSTANTES NAME / NAAM SYMBOL / SIMBOOL | VALUE / WAARDE Standard pressure ; s Standaarddruk P TBI x1 Fa Molar gas volume at STP st Molére gasvolume by STD Vin 22.4 dm'-mol Standard temperature a Standaardtemperatuur qT 273k Charge on electron _ e -1,6x10'"°C Lading op elektron Avogadro's constant 5 Na 6,02« 10” mol Avogadro-konstante TABLE 2: FORMULAE / TABEL 2: FORMULES m N n=— n=-— M Na c=" or co noe Vv MV Vin CaVa _ Ma pH = -log[Hs0"} Cy Mb = = C) e@ _fe a =~ Ecsthode ~ E anode / Ee ~ Ercatode ~ E anode 8 Fe 8 8 sé 8 Feet ~ E reduction ~ Eosidation ! Ea ~ Ereduksie ~ Ecksidasie 8 @ _-fe 8 ~ E reducing agent / Eset _ E oksidearmiddel ~ E recuscermidel = —E° oxidising agent

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Increasing oxidising ability / Toenemende oksiderende vermoé Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY (Paper 2) 10842/19 19 TABLE 4A: STANDARD REDUCTION POTENTIALS TABEL 4A: STANDAARD REDUKSIEPOTENSIALE Half-reactions / Halfreaksies E? wy) Fo(g)+2e° = 2F + 2,87 Co*+e = Co” + 1,81 H2024+2H"+2e = 2H20 +177 MnO] +8H'+5e = Mn" +4H.0 +151 Ch(g)+2e = 2CP + 1,36 crOF + 14H + 66° 2c+7H.0 | +1,33 O.(g)+4H+4e° = 2H,0 + 1,23 MnOz+4H*+2e =. Mn” +2H,O 441,23 Ph+2e Pt + 1,20 BrQt)+2e = 2Br +1,07 O05 +4H'+3e == NO(g)+2H,0 | +0,96 Ho" +2e = Hale) +0,85 Agte = Ag +0,80 NO3 +2H'+e@ = NOAg)+HO | +0,80 Fe*+e = Fe” +0,77 On(g)+2H*+#2e = HeQ2 +0,68 b+2e = ab + 0,54 Cuit+e = Cu +0,52 SQ.+4H'+4e = S+2H,0 +045 2H.0+0,+4e7 = 4OH™ +0,40 Cu*%+2e = Cu +0,34 so i +4H'+2e = SOd(g)+2HO |] +0,17 cut+e = Cu + 0,16 Sn“ +2e = Sn™ + 0,15 $+2H'+2e = HeS(g) + 0,14 2H*+2e = Hela) 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 crite . cr 0,41 Fe*+2e = Fe - 0,44 crt'+3e = Cr - 0,74 Zn" +2e = Zn -0,76 2H2.0+2e == He(g) + 20H" — 0,83 Ce+2e = Cr -0,91 Mn?*+2e° = Mn — 1,18 AM +3e = At 1,66 Mg” +2e .. Mg ~ 2,36 Nate = Na ~ 2,71 Ca*+2e = Ca —2,87 Sft+2e = Sr ~ 2,89 Ba*+2e = Ba — 2,90 Cs'+e = Cs —2,92 K+e = K -2,93 lite = — 3,05 Increasing reducing ability / Toenemende reduserende vermoé

lity / Toenemende oksiderende vermoé ing abi disi ing oxi Increasi Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY (Paper 2) 10842/19 20 TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD REDUKSIEPOTENSIALE Half-reactlons / Halfreaksies E? ”) Lite = Li - 3,05 A Kite = K — 2,93 Cst+e = Cs - 2,92 Ba" +2e . Ba - 2,90 SM+2e = Sr - 2,89 ., Ca +2e = Ca ~ 2,87 2 Na‘+e 2. Na -271 E Mg*+2e = Mg — 2,36 g AM+3e = At - 1,66 ® Mn*+2e = Mn - 1,18 a) cete2e = Cr - 0,91 5 2H,0 +2e = He(g) + 20H" - 0,83 a Zn +2e = Zn ~0,76 8 cré+3e Cr 0,74 B Fe*+2e = Fe - 0,44 o ofte = cr -0,41 3 co +2e =. Cd 0,40 5 Co +22 = Co - 0,28 & Ni*+2e° Ni -0,27 g Sn*+2e = Sn - 0,14 8 Pb? +2e° = Pb - 0,13 - Fe" +3e = Fe = 0,06 a 2H'+2e = Ha{g} 0,00 = S+2H'+2e = H,8(9) +0,14 We] Sn +#2e = Sn* +015 = D cuw+e = Cu" +0,16 £ S07" 44H +20" = SOx(g)+2H:0 | +017 8 Cu*+2e7 = Cu + 0,34 3 2H.O+0,+4e = 40H + 0,40 a SO, + 4H’ + 46" S$ +2H,O + 0,45 = Cute = Cu + 0,52 g b+ 267 2r + 0,54 o Og) + 2H" +20. H:0e +0,68 2 Fe*+e = Fe* +0,77 _ NO3 +2H*+e = NOxg)+H,0 | +0,80 Agite = Ag +0,80 Hg*+2e = Haff) + 0,85 NO3 +4H'+3e = NO(g)+2H,0 | +0,96 Bro(f)+2e = 2Br + 1,07 PR +2e = Pt +1,20 MnO, + 4H* + 2e~ Mn?" + 2H,0 +1,23 0.(g)+4H*+4e7 = 2H. +1,23 crO2 + 14Ht+8e = 20+ THO | +138 Ch(g)+2e = 2Cr + 1,36 MnO 4 +8H*+6e = Mn™ + 4H,0. +1,51 H,O,+2H*+2e = 2H,0 41,77 Co*+e = Co™ +1,81 Fo(g)+2e =F +2,87

Downloaded from hlayiso.com ANSWER SHEET Name: PHYSICAL SCIENCES: CHEMISTRY (Paper 2) 10842/19 21 Attach this page to your answer book. Question 5.3.1 Graph of mass versus time 165,00 164,95 Mass (9) 164,90 164,85 164,80 10 20 30 40 50 Time (s) 60

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