Chemistry 12. Examination Booklet August 2006 Form A DO NOT OPEN ANY EXAMINATION MATERIALS UNTIL INSTRUCTED TO DO SO.

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1 Chemistry 12 Examination Booklet August 2006 Form A DO NOT OPEN ANY EXAMINATION MATERIALS UNTIL INSTRUCTED TO DO SO FOR FURTHER INSTRUCTIONS REFER TO THE RESPONSE BOOKLET Contents: 17 pages Examination: 2 hours 50 multiplechoice questions Additional Time Permitted: 60 minutes 8 writtenresponse questions Province of British Columbia

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3 PART A: MULTIPLE CHOICE Suggested Time: 80 minutes INSTRUCTIONS: For each question, select the best answer and record your choice on the Answer Sheet provided Using an HB pencil, completely fill in the bubble that has the letter corresponding to your answer You have Examination Booklet Form A In the box above #1 on your Answer Sheet, fill in the bubble as follows Exam Booklet Form/ Cahier d examen A B C D E F G H 1 Which of the following would not be units for reaction rate? A gs B M min C kj mol D kpa min 2 Consider the reaction: 2Al( s) + 3CuCl ( aq) Æ 2AlCl ( aq) + 3Cu( s) 2 3 What is the rate of Al consumption in mol min if 098 g Cu are produced in 25 minutes? A mol min B mol min C mol min D mol min Chemistry Form A Page 1

4 3 Which of the following describes what happens to the KE and PE as an activated complex forms products? KE PE A decreases increases B decreases decreases C increases increases D increases decreases Use the following reaction mechanism to answer questions 4 and 5 NO Æ N O Step 1: (fast) Step 2: NO H2 Æ NO 2 + HO 2 (slow) Step 3: NO 2 + H2 Æ N2 + HO 2 (fast) 4 Increasing the concentration of which of the following substances would cause the greatest increase in the reaction rate? A H 2 B NO C NO 2 D HO 2 5 Which of the following are products in the overall reaction? I N 2 II III IV NO 2 2 NO 2 HO 2 A I and II only B I and IV only C II and III only D III and IV only Page 2 Chemistry Form A

5 Use the following diagram to answer questions 6 and 7 PE (kj) Progress of the reaction 6 Which of the following are the values for the activation energy ( E a ) and change in enthalpy ( DH) for the reverse reaction? Ea ( kj) DH ( kj) A B C D If the above PE diagram represents a reversible reaction that reaches equilibrium, which of the following must be true for the forward reaction? A Enthalpy change favours products and entropy is increasing B Enthalpy change favours reactants and entropy is increasing C Enthalpy change favours products and entropy is decreasing D Enthalpy change favours reactants and entropy is decreasing Chemistry Form A Page 3

6 8 Consider the following:? energy + NH SH( s) Æ NH ( g) + H S( g) Which of the following describes how enthalpy and entropy change in the forward direction? Enthalpy Entropy A increasing increasing B increasing decreasing C decreasing decreasing D decreasing increasing 9 Consider the following diagram for the equilibrium system: NO ( g) + energy Æ 2NO ( g) Concentrations (M) NO 2 N 2 O 4 t 1 Time (min) Which of the following stresses was applied at time t 1? [ ] was increased [ ] was decreased A NO 2 B NO 2 4 C Temperature was increased D Temperature was decreased Page 4 Chemistry Form A

7 10 Styrene is manufactured as follows: C6H5CH2CH3( g) + 123kJ Æ C6H5CHCH2( g) + H2( g) styrene Which of the following describes the temperature and pressure needed for the maximum yield of styrene? Temperature Pressure A low low B low high C high low D high high 11 Consider the following reactions: 1 I Na O( s) Æ 2Na( l) + O ( g) K eq = II Na O ( s) Æ 2Na( l) + O ( g) K eq = III 2Na O( s) Æ 4Na( l) + O ( g) K eq = Which of the following lists the reactions in order, from the greatest O 2 least [ O 2 ] at equilibrium? A I, II, III B I, III, II C III, I, II D III, II, I [ ] at equilibrium, to the Chemistry Form A Page 5

8 12 Consider the equilibrium: CaCO3( s) Æ CaO( s) + CO2( g) In a 50 L container at equilibrium there are 242 g CO 2, 100 g CaCO 3 and 100 g CaO Which of the following is the value of K eq? A B C D Consider the following equilibrium: CCl ( g) Æ C( s) + 2Cl ( g) 4 2 [ ] = Initially, 0 31mol CCl 4 was placed in a 1 0L container At equilibrium, Cl M Which of the following is the value of K eq? A B C D Consider the following equilibrium: 3NO ( g) Æ N O ( g) + NO( g) K = eq Initially, some NO 2, NO 2 5 and NO were placed in a container and allowed to reach equilibrium When equilibrium was established, it was found that the pressure had increased Which of the following explains what happened? A Trial Keq > Keq so the system shifted left B Trial Keq < Keq so the system shifted left C Trial Keq > Keq so the system shifted right D Trial K < K so the system shifted right eq eq 11 Page 6 Chemistry Form A

9 15 Which condition is essential to prepare a saturated solution of an ionic salt? A an excess of solute B any amount of solute C a temperature of 25 C D a fixed volume of solvent 16 Which compound will have the greatest solubility? A CoS B CuS C FeS D MgS 17 What is the net ionic equation for the reaction between equal volumes of 0 20M BaS and 020 M BeSO 4? ( ) + ( ) Æ ( ) 2+ 2 A Be aq S aq BeS s ( ) + ( ) Æ ( ) B Ba aq SO aq BaSO s ( ) + ( ) Æ ( ) + ( ) C BaS aq BeSO aq BaSO s BeS s D Ba ( aq) + S ( aq) + Be ( aq) + SO ( aq) Æ BaSO ( s) + Be ( aq) + S ( aq) Which of the following substances will have the least effect on the equilibrium in a saturated solution of PbI2 ( s )? A HI B Na 2 S C NaNO 3 D Pb( NO 3 ) 2 Chemistry Form A Page 7

10 sp = 3+ 2 [ ] [ ] 19 Which equation has the K sp expression: K Al SO A 2Al ( aq) + 3SO ( aq) Æ Al ( SO ) ( s) B Al ( SO ) ( s) Æ Al ( aq) + SO ( aq) C Al ( SO ) ( s) Æ 2Al ( aq) + 3SO ( aq) D 3Al ( aq) + 2SO ( aq) Æ Al ( SO ) ( s) ? 20 What is the K sp for Zn( OH) 2 if it has a solubility of mol L? A B C D Which compound will have the lowest solubility? A AgNO 3 B AgBrO 3 C SrSO 4 D SrCO 3 22 A definition for a BrønstedLowry acid should contain which of the following phrases? A the donation of H + B the donation of OH C the acceptance of H + D the acceptance of OH Page 8 Chemistry Form A

11 23 Which equation represents the reaction of a BrønstedLowry base with water? A 2Na + 2H O Æ 2NaOH + H B NH + HO Æ NH + OH C HPO + H O Æ H O + PO D HCO + HO Æ HO + HCO 24 Given the equilibrium: Which is the strongest acid? A HPO 4 2 B HBO 3 3 C HPO 2 4 D HBO HBO + HPO Æ HBO + HPO + 25 Which species will result in a solution with the greatest [ HO 3 ]? A NaCN B Na 3PO4 C Na2CO3 D Na2C2O4 26 Which species is not amphiprotic? A HO 2 B HBO 3 3 C HPO 2 4 D HCHO Chemistry Form A Page 9

12 27 At a given temperature a sample of pure water has a ph = 710 Which of the following is true? Sample Reason A acidic ph > 7 00 B basic ph > 7 00 C neutral poh < ph [ 3 ] = [ ] D neutral HO OH 28 Which of the following is a definition of ph? + = [ ] A ph log H3O B ph = poh = [ ] C ph log H3O D ph = poh + pkw 29 What is the mass of NaOH required to prepare mlofnaoh( aq) that has a ph = 13 62? A 038 g B 042 g C 167 g D g 30 Which of the following hypothetical acids would have the lowest conductivity? Acid K a A 05 M HY B 10 M HA C 10 M H2B D 20 M HX Page 10 Chemistry Form A

13 31 What is the net ionic equation for the hydrolysis of NH Cl 4? 4 4 A NH Cl( aq) Æ NH ( aq) + Cl ( aq) B Cl ( aq) + H O( ) Æ HCl( aq) + OH ( aq) 2 l C NH + ( aq) + H O( l) Æ H O + ( aq) + NH ( aq) D NH ( aq) + H O( l) Æ HNH ( aq) + OH ( aq) 32 What is the approximate ph of a 0 1M solution of the salt NH4 Cl? A 10 B 50 C 70 D Consider the following indicator equilibrium: HIn( aq) + H O( l) Æ H O ( aq) + In ( aq) 2 3 colourless blue What is the effect of adding HCl to a blue sample of this indicator? Equilibrium Shift Colour Change A left less blue B left more blue C right less blue D right more blue Chemistry Form A Page 11

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15 34 An indicator has a K a = Which of the following is true for this indicator? ph at Transition Point Indicator A 40 methyl orange B 40 bromcresol green C 54 methyl red D 54 bromcresol green 35 Oxalic acid dihydrate is a pure, stable, crystalline substance Which of the following describes one of its uses in acidbase titrations? A buffer B primary standard C chemical indicator D stoichiometric indicator 36 What is the net ionic equation that describes the reaction of HCl( aq) with Pb( OH) 2 ( s)? A H ( aq) + OH ( aq) Æ H2O( l) B 2HCl( aq) + Pb( OH) ( s ) Æ PbCl ( s) + 2H O( l) C 2H ( aq) + 2Cl ( aq) + PbOH ( ) ( s) Æ PbCl ( s) + 2H O( l) D 2H ( aq) + 2Cl ( aq) + Pb ( aq) + 2OH ( aq) Æ Pb ( aq) + 2Cl ( aq) + 2H O( l) 2 37 Which of the following would be used to prepare an acidic buffer solution? A + HF and H 3 O B H2Sand NaHS C NH3 and NH4Cl D HNO3 and NaNO3 Page 12 Chemistry Form A

16 38 Four samples of rain are collected from different geographic regions and the ph is measured for each sample Sample ph Which of the above samples would be classified as acid rain? A 1 only B 1 and 2 C 1, 2 and 3 D 1, 2, 3 and 4 39 Which of the following best describes the process of oxidation? A the process in which oxygen is given off B the process in which electrons are gained C the process in which the oxidation number decreases D the process in which the oxidation number increases 40 What is the oxidation number of N in the mercury(ii) compound Hg( NH3 ) 2Cl2? A 6 B 4 C 3 D Which of the following combinations will react spontaneously under standard conditions? A Ag + Br2 2 + B Ni + Co 2 + C Zn + Mg D Au + HNO3 Chemistry Form A Page 13

17 42 Which of the following is a correctly balanced reduction halfreaction? Æ Æ Æ 2 ( ) A 2HCN + 2e Æ C N + 2H B 2Sb 3H O 6e Sb O 6H C NO H e HNO H O D Sb O H e Sb OH H O 43 Which of the following ion concentrations could be determined by a redox titration using nitric acid? Assume the use of a suitable indicator A Br B Ni 2 + C Fe 2 + D Mn A solution of KMnO 4 is standardized using oxalic acid ( HCO 2 2 4) according to the following equation: MnO + 5H C O + 6H Æ 2Mn + 10CO + 8H O 2 2 The titration of 0 134g of oxalic acid required mlofkmno 4 solution What is the molarity of the KMnO 4 solution? A B C D M M M M Page 14 Chemistry Form A

18 Use the following diagram to answer questions 45 to 47 Volts Cathode Pt (inert) 10 M KNO3 Anode Cu Layer 1: 10 M NaBr(aq) Layer 2: Br 2 (l) 45 What is the cathode reaction for this cell? A Na + e Æ Na B Br2 + 2e Æ 2Br 2 1 C 2Br Æ Br + 2e D HO 2 Æ O H e M Cu(NO 3 ) 2 46 Which of the following best describes the movement of potassium ions and electrons as the cell operates? K + Ion Movement Electron Movement A towards the Cu towards the Pt B towards the Cu towards the Cu C towards the Pt towards the Cu D towards the Pt towards the Pt 47 What is the standard cell voltage? A 0 75V B +0 62V C +0 75V D +1 43V Chemistry Form A Page 15

19 48 A student constructs three standard electrochemical cells using the metals Pd, Cd and Ga with 10 M solutions of their ions The student then records the voltages of Cell 1 and Cell 2 in the following table What voltage should Cell 3 produce? A 1 34V B 1 02V C +1 02V D +1 34V Cell Anode Cathode Voltage 1 Ga Pd +1 18V 2 Ga Cd +0 16V 3 Cd Pd? 49 Which of the following would prevent the corrosion of an iron nail? A Store the nail incl2 ( g) B Store the nail in dry air C Store the nail in a beaker of distilled water D Store the nail wrapped in cobalt wire in a beaker of distilled water Page 16 Chemistry Form A

20 50 Consider the electrolytic cell shown in the following diagram: DC Power Source + Pt (inert) Cu 10 M AgNO 3 Which of the following describes the anion movement and electrode masses for the above cell? Anion Movement Mass of Pt Electrode Mass of Cu Electrode A to the Cu increases increases B to the Cu increases decreases C to the Pt decreases increases D to the Pt decreases decreases You have Examination Booklet Form A In the box above #1 on your Answer Sheet, ensure that you have filled in the bubble as follows Exam Booklet Form/ Cahier d examen A B C D E F G H This is the end of the multiplechoice section Answer the remaining questions in the Response Booklet Chemistry Form A Page 17

21 PERIODIC TABLE OF THE ELEMENTS Be Beryllium 90 5 B Boron C Carbon N Nitrogen O Oxygen F Fluorine H He Hydrogen Helium Ne Neon Atomic Number Symbol Name Atomic Mass 3 Li Lithium i Si i i Silicon Na Mg Sodium Magnesium Aluminum Silicon Phosphorus Sulphur Chlorine Argon Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Ni Cu Zn Ga Ge As Se Br Kr Rb Y Zr Nb Mo Tc Ru Rh Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon (98) Sr Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Cesium Barium Lanthanum Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon (209) (210) (222) Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Francium Radium Actinium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium (223) (226) (227) (261) (262) (263) (262) (265) (266) Sg Bh Hs Mt 58 Ce Cerium Based on mass of C 12 at Th Thorium Pr Praseodymium Pa Protactinium Nd Neodymium U Uranium Pm Promethium (145) 93 Np Neptunium (237) 62 Sm Samarium Pu Plutonium (244) 63 Eu Europium Am Americium (243) 64 Gd Gadolinium Cm Curium (247) 65 Tb Terbium Bk Berkelium (247) 66 Dy Dysprosium Cf Californium (251) 67 Ho Holmium Es Einsteinium (252) 68 Er Erbium Fm Fermium (257) 69 Tm Thulium Md Mendelevium (258) 70 Yb Ytterbium No Nobelium (259) 71 Lu Lutetium Lr Lawrencium (262) Values in parentheses are the masses of the most stable or best known isotopes for elements which do not occur naturally Chemistry 12 Data Page 1

22 ATOMIC MASSES OF THE ELEMENTS Based on mass of C 12 at 1200 Values in parentheses are the mass number of the most stable or best known isotopes for elements that do not occur naturally Data Page 2 Chemistry 12 Actinium Aluminum Americium Antimony Argon Arsenic Astatine Barium Berkelium Beryllium Bismuth Boron Bromine Cadmium Calcium Californium Carbon Cerium Cesium Chlorine Chromium Cobalt Copper Curium Dubnium Dysprosium Einsteinium Erbium Europium Fermium Fluorine Francium Gadolinium Gallium Germanium Gold Hafnium Helium Holmium Hydrogen Indium Iodine Iridium Iron Krypton Lanthanum Lawrencium Lead Lithium Lutetium Magnesium Manganese Mendelevium Ac Al Am Sb Ar As At Ba Bk Be Bi B Br Cd Ca Cf C Ce Cs Cl Cr Co Cu Cm Db Dy Es Er Eu Fm F Fr Gd Ga Ge Au Hf He Ho H In I Ir Fe Kr La Lr Pb Li Lu Mg Mn Md (227) 270 (243) (210) 1373 (247) (251) (247) (262) 1625 (252) (257) 190 (223) (262) (258) Mercury Molybdenum Neodymium Neon Neptunium Nickel Niobium Nitrogen Nobelium Osmium Oxygen Palladium Phosphorus Platinum Plutonium Polonium Potassium Praseodymium Promethium Protactinium Radium Radon Rhenium Rhodium Rubidium Ruthenium Rutherfordium Samarium Scandium Selenium Silicon Silver Sodium Strontium Sulphur Tantalum Technetium Tellurium Terbium Thallium Thorium Thulium Tin Titanium Tungsten Uranium Vanadium Xenon Ytterbium Yttrium Zinc Zirconium Hg Mo Nd Ne Np Ni Nb N No Os O Pd P Pt Pu Po K Pr Pm Pa Ra Rn Re Rh Rb Ru Rf Sm Sc Se Si Ag Na Sr S Ta Tc Te Tb Tl Th Tm Sn Ti W U V Xe Yb Y Zn Zr (237) (259) (244) (209) (145) 2310 (226) (222) (261) (98) Element Symbol Atomic Number Atomic Mass Element Symbol Atomic Number Atomic Mass

23 NAMES, FORMULAE, AND CHARGES OF SOME COMMON IONS * Aqueous solutions are readily oxidized by air ** Not stable in aqueous solutions Positive Ions (Cations) Al 3+ Aluminum Pb 4+ Lead(IV), plumbic NH 4 + Ammonium Li + Lithium Ba 2+ Barium Mg 2+ Magnesium Ca 2+ Calcium Mn 2+ Manganese(II), manganous Cr 2+ Chromium(II), chromous Mn 4+ Manganese(IV) Cr 3+ Chromium(III), chromic Hg 2 2+ Mercury(I)*, mercurous Cu + Copper(I)*, cuprous Hg 2+ Mercury(II), mercuric Cu 2+ Copper(II), cupric K + Potassium H + Hydrogen Ag + Silver H 3 O + Hydronium Na + Sodium Fe 2+ Iron(II)*, ferrous Sn 2+ Tin(II)*, stannous Fe 3+ Iron(III), ferric Sn 4+ Tin(IV), stannic Pb 2+ Lead(II), plumbous Zn 2+ Zinc Negative Ions (Anions) Br Bromide OH Hydroxide CO 3 2 Carbonate ClO Hypochlorite ClO 3 Chlorate I Iodide Cl Chloride HPO 4 2 Monohydrogen phosphate ClO 2 Chlorite NO 3 Nitrate CrO 4 2 Chromate NO 2 Nitrite CN Cyanide C 2 O 4 2 Oxalate Cr 2 O 7 2 Dichromate O 2 Oxide** H 2 PO 4 Dihydrogen phosphate ClO 4 Perchlorate CH 3 COO Ethanoate, acetate MnO 4 Permanganate F Fluoride PO 4 3 Phosphate HCO 3 Hydrogen carbonate, bicarbonate SO 4 2 Sulphate HC 2 O 4 Hydrogen oxalate, binoxalate S 2 Sulphide HSO 4 Hydrogen sulphate, bisulphate SO 3 2 Sulphite HS Hydrogen sulphide, bisulphide SCN Thiocyanate HSO 3 Hydrogen sulphite, bisulphite Chemistry 12 Data Page 3

24 SOLUBILITY OF COMMON COMPOUNDS IN WATER The term soluble here means > 01 mol/l at 25 C Negative Ions (Anions) Positive Ions (Cations) Solubility of Compounds All Alkali ions: Li +, Na +, K +, Rb +, Cs +, Fr + Soluble All Hydrogen ion: H + Soluble All Ammonium ion: NH 4 + Soluble Nitrate, NO 3 All Soluble or or Chloride, Cl Bromide, Br Iodide, I All others Ag +, Pb 2+, Cu + Soluble Low Solubility Sulphate, SO 4 2 All others Ag +, Ca 2+, Sr 2+, Ba 2+, Pb 2+ Soluble Low Solubility Sulphide, S 2 Alkali ions, H +, NH 4 +, Be 2+, Mg 2+, Ca 2+, Sr 2+, Ba 2+ All others Soluble Low Solubility Hydroxide, OH Alkali ions, H +, NH + 4, Sr 2+ All others Soluble Low Solubility or or Phosphate, PO 4 3 Carbonate, CO 3 2 Sulphite, SO 3 2 Alkali ions, H +, NH 4 + All others Soluble Low Solubility Data Page 4 Chemistry 12

25 SOLUBILITY PRODUCT CONSTANTS AT 25 C Name Barium carbonate Barium chromate Barium sulphate Calcium carbonate Calcium oxalate Calcium sulphate Copper(I) iodide Copper(II) iodate Copper(II) sulphide Iron(II) hydroxide Iron(II) sulphide Iron(III) hydroxide Lead(II) bromide Lead(II) chloride Lead(II) iodate Lead(II) iodide Lead(II) sulphate Magnesium carbonate Magnesium hydroxide Silver bromate Silver bromide Silver carbonate Silver chloride Silver chromate Silver iodate Silver iodide Strontium carbonate Strontium fluoride Strontium sulphate Zinc sulphide Formula BaCO 3 BaCrO 4 BaSO 4 CaCO 3 CaC 2 O 4 CaSO 4 CuI Cu(IO 3 ) 2 CuS Fe(OH) 2 FeS Fe(OH) 3 PbBr 2 PbCl 2 Pb(IO 3 ) 2 PbI 2 PbSO 4 MgCO 3 Mg(OH) 2 AgBrO 3 AgBr Ag 2 CO 3 AgCl Ag 2 CrO 4 AgIO 3 AgI SrCO 3 SrF 2 SrSO 4 ZnS K sp Chemistry 12 Data Page 5

26 RELATIVE STRENGTHS OF BRØNSTEDLOWRY ACIDS AND BASES in aqueous solution at room temperature Name of Acid Acid Base K a STRONG STRENGTH OF ACID WEAK 4 4 Perchloric HClO Æ H + ClO Hydriodic HI Æ H + I Hydrobromic HBr Æ H + Br Hydrochloric HCl Æ H + Cl 3 3 Nitric HNO Æ H + NO very large very large very large very large very large Sulphuric H2SO4 Æ H + HSO4 very large + + Hydronium Ion H3O Æ H + H2O 10 Iodic HIO3 Æ H + IO Oxalic H C O Æ H + HC O Sulphurous ( SO2 + H2O) H2SO3 Æ H + HSO3 Hydrogen sulphate ion HSO4 Æ H + SO Phosphoric H PO Æ H + H PO Hexaaquoiron ion iron III ion Fe( H2O) 6 Æ H + Fe( H2O) ( OH) +, ( ) 5 Citric H3C6H5O7 Æ H + H2C6H5O7 Nitrous HNO2 Æ H + NO Hydrofluoric HF Æ H + + F Methanoic, formic HCOOH Æ H + HCOO Hexaaquochromium ion, chromium( III) ion Cr( H2O) Æ H + Cr( H O) ( OH) Benzoic C6H5COOH Æ H + C6H5COO Hydrogen oxalate ion HC2O4 Æ H + C2O4 Ethanoic, acetic CH COOH 3 H CH3COO Dihydrogen citrate ion H C H O Æ H + HC H O Hexaaquoaluminum ion, aluminum ion Al( H O) Æ H + Al( H O) ( OH) Carbonic ( CO2 + H2O) H2CO3 Æ H + HCO Monohydrogen citrate ion 2 + HC6H5O7 Æ H + CHO Hydrogen sulphite ion HSO3 Æ H + SO Hydrogen sulphide H2S Æ H + HS Dihydrogen phosphate ion H2PO4 Æ H + HPO Boric H3BO3 Æ H + H2BO Ammonium ion NH4 Æ H + NH Hydrocyanic HCN Æ H + CN Phenol C6H5OH Æ H + C6H5O Hydrogen carbonate ion HCO3 Æ H + CO Hydrogen peroxide H2O2 Æ H + HO Monohydrogen phosphate ion 2 HPO4 Æ H + PO Water H O Æ H + OH Hydroxide ion 2 OH H + O very small 3 2 Ammonia NH H + NH very small 14 WEAK STRENGTH OF BASE STRONG Data Page 6 Chemistry 12

27 ACIDBASE INDICATORS Indicator Methyl violet Thymol blue Orange IV Methyl orange Bromcresol green Methyl red Chlorophenol red Bromthymol blue Phenol red Neutral red Thymol blue Phenolphthalein Thymolphthalein Alizarin yellow Indigo carmine ph Range in Which Colour Change Occurs Colour Change as ph Increases yellow to blue red to yellow red to yellow red to yellow yellow to blue red to yellow yellow to red yellow to blue yellow to red red to amber yellow to blue colourless to pink colourless to blue yellow to red blue to yellow Chemistry 12 Data Page 7

28 STANDARD REDUCTION POTENTIALS OF HALFCELLS Ionic concentrations are at 1M in water at 25 C Oxidizing Agents Reducing Agents F2 ( g)+ 2e Æ 2F SO e Æ 2SO HO H + 2e Æ 2HO MnO4 + 8H + 5e Æ Mn + 4H2O Au + 3e Æ Au() s BrO3 + 6H + 5e Æ 2 Br2()+ l 3H2O ClO4 + 8H + 8e Æ Cl + 4H2O Cl2( g)+ 2e Æ 2Cl Cr2O H + 6e Æ 2Cr + 7H2O O2( g)+ 2H + 2e Æ HO MnO2()+ s 4H + 2e Æ Mn + 2H2O IO3 + 6H + 5e Æ 2 I2()+ s 3H2O Overpotential Br2 ()+ l 2e Æ 2Br Effect AuCl4 + 3e Æ Au()+ s 4Cl NO3 + 4H + 3e Æ NO( g)+ 2H2O Hg + 2e Æ Hg() l O ( g )+ 2H ( 10 M)+ 2e Æ H2O NO3 + 4H + 2e Æ N2O4 + 2H2O Ag + e Æ Ag() s Hg2 + e Æ Hg() l Fe + e Æ 2+ Fe O2( g)+ 2H + 2e Æ H2O MnO4 + 2H2O + 3e Æ MnO2()+ s 4OH I2()+ s 2e Æ 2I Cu + e Æ Cu() s HSO H + 4e Æ Ss ()+ 3HO Cu + 2e Æ Cu() s SO4 + 4H + 2e Æ H2SO3 + H2O Cu + e Æ + Cu Sn + 2e Æ 2+ Sn Ss ()+ 2H + 2e Æ H2Sg ( ) H + 2e Æ H2( g) Pb + 2e Æ Pb() s Sn + 2e Æ Sn() s Ni + 2e Æ Ni() s 026 HPO H + 2e Æ HPO HO Co + 2e Æ Co() s 028 Se()+ s 2H + 2e Æ H2Se Cr + e Æ 2+ Cr HO 2 + 2e Æ H2 + 2OH ( 10 M) Fe + 2e Æ Fe() s 045 Overpotential 2 Ag2S()+ s 2e Æ 2Ag()+ s S 069 Effect 3 Cr + 3e Æ Cr() s Zn + 2e Æ Zn() s 076 Te()+ s 2H + 2e Æ H2Te 079 2HO 2 + 2e Æ H2( g)+ 2OH Mn + 2e Æ Mn() s Al + 3e Æ Al() s Mg + 2e Æ Mg() s 237 Na + e Æ Na() s Ca + 2e Æ Ca() s Sr + 2e Æ Sr() s Ba + 2e Æ Ba() s 291 K + e Æ K() s 293 Rb + e Æ Rb() s 298 Cs + e Æ Cs() s 303 Li + e Æ Li() s 304 Data Page 8 Chemistry 12 STRONG STRENGTH OF OXIDIZING AGENT WEAK E ( Volts ) WEAK STRENGTH OF REDUCING AGENT STRONG

29 MINISTRY USE ONLY MINISTRY USE ONLY Question (5) NR Question (5) NR Place Personal Education Number (PEN) here Question (5) NR Course Code = CH 12 AUGUST 2006 Question (5) NR Question (5) NR Exam Booklet, Form/ Cahier d examen A B C D E F G H Question (5) NR Student Instructions 1 Place your Personal Education Number (PEN) label at the top of this Booklet AND fill in the bubble (Form A, B, C, D, E, F, G or H) that corresponds to the letter on your Examination Booklet 2 Use a pencil to fill in bubbles when answering questions on your Answer Sheet 3 Use a pencil or blue or blackink pen when answering writtenresponse questions in this Booklet 4 Read the Examination Rules on the back of this Booklet Question (5) NR Question (5) NR 814 bia Version 06011

30 MINISTRY USE ONLY Place Personal Education Number (PEN) here Course Code = CH 12 Chemistry 12 AUGUST 2006 Response Booklet Province of British Colum

31 PART B: WRITTEN RESPONSE Suggested Time: 40 minutes INSTRUCTIONS: Answer the following questions in the space provided in this Response Booklet You are expected to communicate your knowledge and understanding of chemical principles in a clear and logical manner Your steps and assumptions leading to a solution must be written in this Response Booklet Answers must include units where appropriate and be given to the correct number of significant figures For questions involving calculations, full marks will NOT be given for providing only an answer 1 Consider the reaction: 2Zn( s) + O ( g) Æ 2ZnO( s) 2 State two different methods that would increase the rate of this reaction Explain each in terms of collision theory (4 marks) Method 1: Explanation: Method 2: Explanation: 2 Consider the equilibrium: CO ( g) + H ( g) Æ CO( g) + H O( g) K = eq 160 Initially, 8 2mol of CO and 82 mol of H2O are placed in a 20 L container and allowed to react Calculate the equilibrium concentrations of CO2 and CO (4 marks) Chemistry Response Booklet Page 1

32 3 What is the maximum Pb 2 + precipitate formation? [ ] that can exist in a saturated solution of BaSO 4 without causing (4 marks) 4 Given the reactants: HCO HCOO Æ Complete the acidbase equilibrium equation in the box above Determine whether reactants or products will be favoured and explain why (3 marks) Page 2 Chemistry Response Booklet

33 5 Calculate the ph of a 0 30M H2S solution Begin by writing the equation for the predominant reaction (5 marks) 6 What mass of NaOH( s) is required to just neutralize 50 0 ml of 2 0 M H2SO 4? Begin by writing the balanced equation for the neutralization reaction (3 marks) Chemistry Response Booklet Page 3

34 7 Balance the following in acidic solution 2 3+ FeS + NO Æ NO + SO + Fe ( acidic) 2 4 (4 marks) 8 The electrolysis of copper(ii) sulphate solution using copper electrodes is used in the refining of copper Write the anode and cathode halfreactions and describe what would be observed at each electrode as the cell operates (3 marks) Anode HalfReaction: Cathode HalfReaction: Observations: anode: cathode: END OF EXAMINATION Page 4 Chemistry Response Booklet

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36 Examination Rules 1 The time allotted for this examination is two hours You may, however, take up to 60 minutes of additional time to finish 2 Answers entered in the Examination Booklet will not be marked 3 Cheating on an examination will result in a mark of zero The Ministry of Education considers cheating to have occurred if a student breaks any of the following rules: Candidates must not give or receive assistance of any kind in answering an examination question during an examination, including allowing one s paper to be viewed by others or copying answers from another student s paper Candidates must not possess any book, paper or item that might assist in writing an examination, including a dictionary or piece of electronic equipment, that is not specifically authorized for the examination by ministry policy Candidates must immediately follow the invigilator s order to stop writing at the end of the examination time and must not alter an Examination Booklet, Response Booklet or Answer Sheet after the invigilator has asked students to hand in examination papers Candidates must not communicate with another student during the examination Candidates must not remove any piece of the examination materials from the examination room, including work pages Candidates must not take or knowingly use any secure examination materials prior to the examination session 4 The use of inappropriate language or content may result in a mark of zero being awarded 5 Upon completion of the examination, return all examination materials to the supervising invigilator