Physical Sciences Grade 12 P2 Limpopo November 2017 QP

Downloaded from hlayiso.com lalalaiahaiabsinlatetahtelalededetelelslalndslaielalalalsdehaleiatalelalelaileladetel PHYSICAL SCIENCES P2: CHEMISTRY : SEPTEMBER 2017 OPPS P Vier ret errri rit r tri i rt rrr st tT Tit tT) MARKS: 180 TIME: 3 hours. This question paper consists of 16 pages and 4 date sheets.

Downloaded from hlayiso.com Physical Sciences/P2 2 LimpopoDobiSeptember 2017 NSC INSTRUCTIONS AND INFORMATION 1. XP we w oe 10. 41. Write your NAME in the appropriate space on the ANSWER BOOK. This question paper consists of TEN questions. Answer ALL the questions in the ANSWER BOOK. Start EACH question on a NEW page in the ANSWER BOOK. You may uae a non-programmable calculator. You may use appropriate mathematical instruments. YOU ARE ADVISED TO USE THE ATTACHED DATA SHEETS. Number the answers correctly according to the numbering system used in this question paper. Give brief motivations, discussions, et cetera where required. Show ALL formulas and substitutions in ALL calculations. Round off your final numerical answers to a minimum of TWO decimal places. Write neatly and legibly Copyight reserved Please tum over

Downloaded from hlayiso.com Physical Selences/P2 3 LimpopoDot/Septembar 2017 NSC QUESTION 4: 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 nuriber (1.1 ~ 1.10) in the ANSWER BOOK. VW How many moles of water will be formed when one mole of ethane (CjHs} burns in an excess of oxygen? 2 Cols + 8 Oz + 2 COn + 6 HO A 6 B 4 c 3 D 1 (2) 1.2 An example of how useful products are obtained by the cracking of long chain hydrocarbons ie represented by the equation below. Celie — Cate + ¥ In this reaction, compound ¥ is: A Propanal 8 Propyne C Propene D Propane 2} 4.3. The monomer of polyethene is: A Ethane B Ethene c Ethyne oO Propene {2} Copyright reserved Please turn. over

Downloaded from hlayiso.com Physical Sciances/P2 4 LimpopoDoE/September 2017 NSC 1.4 The graph below shows the changes in the amounts of X,Y and Z versus time during a reaction. i xX i 5 Y == z ra * Lt) 1 2 time (3) The equation for the reaction can be represented as follows: A X#YuodZ B 5X + By > 2Z c 3X + B¥ 4 Z ia] 2K + BY ~~ 22 @ 15 A chemical equilibrium is established whan... A No further reactions take place. B None of the original chemicals are left. fe The concantrations of all chemicals are equal. D The rates of the forward and reverse reactions are equal. @ 16 in which ONE of the following reactions will the yield of the products be favoured by an increase in the pressure on the reaction mixture? A 2.NOig) + Chig) = 2 NOCKg) 5 COW) + H2Q(g) = CO2g) + Hefg) c 2 SOs{g) + 2 502g) + O7(g) D PCi(g) = PCix(g) + Chxg) @2 Please lum over Copyright reserved

Downloaded from hlayiso.com Physical Sciencew/P2 Nec LimpopoDoE/September 2017 7 Which one of the following is CORRECT for a solution with pH = 47 1.8 1.9 1.10 Copyright reserved oo w Pm [H"{aq)] = 10° mod {OH (aq)] = 107° mold? [H*(aq)] = 10* mobdm* [O#H (aq)] = 10% mold’? (2) A beaker contains @ 0,01 mol-dm’® NaOH-solution. A spoonful of a soluble compound, X, is added to the solution and the pH of the solution decreases. Which ONE of the following can be compound XK? A B c DB Ammonium carbonate Ammonium chloride Potassium nitrate Sodium chloride 3) A reaction is represented by the following equation: MnQz + 4HCl = MnCh + 2H,0 + Ch In this reaction MnO, acts as: A An alkali 8 A catalyst c An oxidising agent D A taducing agent 2) The main products formed by the Haber and Ostwald processes tespectively are: Haber process Ostwald process A Nitrogen Nitric acid B Nivogen Asnmonia c Ammonia Sulphuric acid DB Arrnonia ; Nitric acid (2) [20] Please turn over

Downloaded from hlayiso.com Physical Sciences/P2 6 LimpopoDo&/Saptember 2017 NSC QUESTION 2 (Start on a new page} The letters A to F in the table below represent six organic compounds. HC Cee GG B Hexanoic acid i i | H CH,H H C CHsCHyCH,CHO BD CHCCH, F GH E CH ~ CH: ~ CHe ; Jd H Br CH: OH i ot CHy-CH2-GH-GH-CHe- CH Use the information in the table (where applicable) tc answer the following questions: 24 White down the: 2.1.1 IUPAC name of compound A (2) 2.12 IUPAC name of compound F (2) 2.1.3 Structural formula of compound D (i) 2.2 What is a structural isomer? @) 2.3 Which compound in the above table is a functional isomer of ethyl butanoate? @) 24 Compound E reacts with compound B. Give the IUPAC name of the organic product that is formed. Oy Copyright reserved Please turn over

Physical Sciences/P2 7 Downloaded from hlayiso.com NSC QUESTION 3 (Start on a new page) Leamers investigate factors that influence boiling point. The results obtained are shown in the table below. 3.4 3.2 3.3 34 3.5 LimpopoDok/September 2017 BOILING COMPOUND MOLECULAR | “poNT MASS fC) A CHy(CH2),COOK 88 184 8 CHACH2,OH 88 138 c CH,COOC Hs 88 bra Define the term boiling point. From the table write dawn: 3.2.1 The independent variable 322 The dependent variable 32.3 Acontrol variable 2) ty mM 1) What type of intermolecular force is found between molecules of compound A, which is not found in compound C? Compound B has a much higher balling paint than compound C. Fully explain this observation by referring to the type of intermolecular forces In each. 2,2-dimethylpropan-1-ol is a structural isomer of compound B. 3.5.1 What is this type of an isomer called? (4) (4) a) 3.5.2 Will the vapour pressure of 2,2-dimethylpropan-1-ol bs HIGHER THAN, LOWER THAN or THE SAME as that of compound B? Copyright reserved 1) hq Please turn over

Downloaded from hlayiso.com Physical Sclances/?)2 nec LimpopoDoE/Geptember 2017 QUESTION 4 (Start on a new page) 41 Different organic compounds have different properties due to different functional groups. 4.4.4 Define the term functional group. (2) 4.12 Carboxylic acids, ketones and aldehydes all contain a carbonyl group. Give the structural formula of & carbonyl group. (1) 42 Sludy the flow diagram below and answer the questions that low. 41-chioropropane Compound X A \ Her ‘-propene H2C= CHACHs Alcohol W moms Compound Z For reaction B write down the: 4.2.1 Balanced equation using structural formulae for the organic reactants and products 5) 422 Type of reaction that occurs a) 42.3 Reaction conditions needed 2) ‘Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sciences/F2 9 LirmpopoDokGeptember 2017 NSC Alcohol W is produced in reaction A. 4.2.4 Write down the IUPAC name of alcohol W. oh] 4.2.5 Ie alcohol W a primary or a secondary alcohol? (1) For reaction C write down the: 4.2.8 Balanced equation using structural formulae for the organic reactants and products 3] 4.2.7 Type of reaction that occurs (1) Consider reaction D. 4.2.8 How will you know that compound Z has formed? (1) 428 Towhich homologous series does compound Z belong? a) 4.2.10 Write down the structural formula of the functional group of Copyright reserved Please turn over

Downloaded from hlayiso.com Physical Sclences/P2 10 LimponoDoEsSeptember 2017 NSC QUESTION 6 (Start on a new page} Manganese dioxide (MnO) acts as a CATALYST in the decomposition of hydrogen peroxide to produce water and oxygen. The equation for the reaction is as follows: MnO 2H,0.(aq) > 2H,0()) + On(g) One gram (1 g) of MnO. powder is added to a hydrogen peroxide solution with a concentration of 2 mobdm’ af 25 °C and the volume Ooty) which Is formed Is measured with a gas syringe. The sketch graph below shows the results which were obtained. Volume Oz (cm) Time (minutes) 54 Define the term catalyst. @) 5.2 Redraw the graph in your answer book. 62.1 On THE SAME system of axes, sketch the graph that would be obtained dno catalyst is used. Label this graph A. 1) 5.2.2 On THE SAME system of axes, sketch the graph that would be obtained if more hydrogen peroxide, at a higher temperature, also with 1 g MnO powder as catalyst, decomposes. Label this graph B. 2) 5.3 What mass of MnO. will be ieft at the end of the experiment? (1 5.4 Define the term reaction rato. (2) 5.5 Usa the collision theory and explain how a catalyst increases the rate of a reaction. oe Copyright reserved Please tun over

Downloaded from hlayiso.com Physical Sciences/P2 wt LimpopadoE/September 2017 QUESTION 6 (Start on a new page) 61 Study the reaction below: NLO.g) & ZhOaal AH = +58 ks-mof! (colourless) 6.2 sheer prcrsroney teat 20m anid the activation energy for the forward reaction ie 90 k-mol", 6.1.1 Oraw a potential energy diagram for the course of this reaction. indicate the following on your diagram: « Energy of the reactants « Energy of activated complex + Activation energy of forward reaction re) 8.1.2 On the same diagram, use a dotted line to indicate the effect of a catalyst on this reaction. WH 6.1.3 Which reaction will be favoured if the temperature of the reaction mixture Is increased? (Write only FORWARD or REVERSE.) a 614 Use Le Chatelier’s Principts to explain the answer to QUESTION 6.1.3, @} The hypothetical reaction shown below takes place In a sealed container. Adg) + Big) 2ARKg) The change in the equilibrium constant, K,, al different temperatures, is ahown in the table below. Temperature ("C) Ke 1000 6,6 750 20 560 os Use the information in the table and indicate whether the REVERSE REACTION is exothermic or endothermic. Briefly explain your answer, Q) Copyright reserved Please tum over

Downloaded from hlayiso.com Physical Sciences/P2 12 LimpopoDaE/Septerber 2017 NSC 63 Study the reversible reaction represented by the balanced equation below: Ho(g) + COxg) @ H20(g) + CO(g) initially x moles H2(9) are mixed with 0,3 moles CO2(g) ina sealed 10 dm° container. When equilibrium is reached at a certain temperature, it is found that 0,2 moles Hy,0(g) are present. The equilibrium constant (K.) for this reaction at this temperature is 4. 6.3.1 Calculate the initial number of moles, x, of He(g) which were in the container. (9) 6.3.2 The concentration of COz gas is now increased. How does this change affect the value of the equilibrium constant (Ke)? Write only INCREASES, “SECREASES or REMAINS THE SAME. (1) RY Copyright reserved Please tum over

Downloaded from hlayiso.com Physical Sciencea/P2 13 LimpopoDoE/September 2017 NSC QUESTION 7 (Start on a new page) 74 The hydrogen carbonate ion (HCO; ) can act as both an acid and a base. 7.1.1 Define an acid and a base in terms of the Lowry-Bronsted theory. @) 7.1.2 What are substances, which can act as both an acid and a base, called? Q Consider the following equations: A. HyCO3+ H2O = H,0* + HCO; B. HCO; +H,O # HsO0* + CO? 7.1.3 In which of the above reactions dees HCO; acts as an acid? Answer only A or B. @) 7.44 Give the conjugate base of H:COs. ra 7.1.5 Why is HCO, a diprotic acid? a) 72 60 om” of a 0,50 moldm® solution of hydrochloric acid is added to 0,8 g of solid calcium carbonate (CaCO,). The CaCO; reacts completely, The balanced equation for the reaction is as follows: 2HCI + CaCO, ~ CaCh + CO. + HO 7.24 Galoulate the number of moles of HCI that have reacted with the CaCOs, i) 7.2.2 Calculate the pH of the solution when the reaction is Copyright reserved Piease turn over

Downloaded from hlayiso.com Physical Sciences/P2 ni LimpopoDof/Saptamber 2017 QUESTION 6 (Start on a new page) A learner sets up a standard Ni-Cu electrochemical call and connects it to 3 0,5 V bub. a4 Write down the cell notation for this cell. Q) 8.2 ‘What ie the polarity of the Ni electrode? ( 8.3 Which electrode is the cathode? (1) 84 Use a relevant calculation to determine whether the bulb will burn or not. 4 Copyright reserved Pigase turn over

Downloaded from hlayiso.com Physical Sclences/P2 15. LimpopeDoE/September 2017 NSC QUESTION 9 (Start on a new page) The simplified diagram below represents an electrolytic cell which is used for the electrolysis of a concentrated sodium chloride solution. Power Source al | Concentrated NaC! (aq) Chlorine gas is released at electrode Y. 9.4 Which electrode, X or ¥, is positive? 9.2 ‘What will be formed at electrode X? 9.3 Wiite down the haif reaction to explain your answer to QUESTION 9.2, 2.4 is X the cathode or the anode’? 9.5 in which direction do electrons fiow in the extemal circuit? (Kto ¥ or ¥ toX.) 9.6 Give the NAME of the substance that acts as reducing agent. 9.7 Write a balanced net equation for the reaction that takes place in this cell. Copyright reserved a) (1) @) @ () a) @) ta] Please tum over

Downloaded from hlayiso.com Physical Sciences/P2 16 LimpopeDoE/Septamber 2017 NSC QUESTION 10 (Start on a new page) A group of learners want to start a vegetable garden at school to supply the community with vegetables. They are given three bags of fertilizer by a farmer. The three bags are marked as follows: FERTILIZER A: 3:2:1 (28) FERTILIZER B: | 2:3:4 (22) FERTILIZER C: Ammonium sulphate 10.1 What is represented by each of the following in fertilizer A7 1.4.1 3:21 10,12 28 10.2 Calculate the: 10.2.1 Percentage nitrogen in fertilizer A (1) ) @) 10.22 Mass of potassium present in a 20 kg bag of fertilizer B 3) 10.3 Write a balanced equation for the preparation of fertilizer C from ammonia and a suitable acid. Q) 10.4 — Give the name of the process which is used to manufacture the acid needed for the preparation of fertilizer C. () 10.6 Name ONE function of phosphorous in plants, a) After some time a fish pond in the garden tus green and starts to 10.6 Name the phenomenon which ocours in the fish pond. (i) 10.7 Give a possible cause for the phenomenon in QUESTION 10.6. (Wy 10.8 Name ONE negative impact that this phenomenon may have, he GRAND TOTAL: 180 Copyright reserved