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徐老湿留学 AVOGADRO EXAM 2010 UNIVERSITY OF WATERLOO DEPARTMENT OF CHEMISTRY 13 MAY 2010 TIME: 75 MINUTES This exam is being written by several thousand students. Please be sure that you follow the instructions below. We'll send you a report on your performance. Top performers are eligible for a prize. The names of the top 200 students will be published in the September issue of Chem 13 News. 1. Print your name here: 2. Print your school name and city on your STUDENT RESPONSE sheet. 3. Select, and enter on the STUDENT RESPONSE sheet, one of the following CODE numbers: Code 1 Ontario, now studying Grade 11 Chemistry in a nonsemestered school Code 2 Ontario, now studying Grade 11 Chemistry in a semestered school Code 3 Ontario, Grade 11 Chemistry already completed Code 4 Any other Ontario student Code 5 Manitoba or Saskatchewan high school student Code 6 Québec high school student Code 7 Code 8 not used Alberta or British Columbia high school student Code 9 New Brunswick, Newfoundland, Nova Scotia, or Prince Edward Island high school student Code 10 Northwest Territories, Nunavut, or Yukon high school student 4. Print your name (last name, first name and optional middle initial) on the STUDENT RESPONSE sheet. Also fill in the corresponding circles below your printed name. 5. Carefully detach the last page. It is the datasheet. 6. Now answer the exam questions. Questions are not in order of difficulty. Indicate your choice on the STUDENT RESPONSE sheet by marking one letter beside the question number. • Mark only one answer for each question. • Questions are all of the same value. • There is a penalty (1/4 off) for each incorrect answer, but no penalty if you do not answer. 7. Take care that you make firm, black pencil marks, just filling the oval. Be careful that any erasures are complete—make the sheet white again. Code 11 High school student outside Canada Code 12 Teacher Carefully detach the last page. It is the Data Sheet. 徐老湿留学 1 Compared to an electron, a proton has 5 A the same charge and about the same mass A O3 B the same charge but a much greater mass B NO2− C the opposite charge and much less mass C C2H2 D the opposite charge and a much greater mass D H2S E no charge and a much smaller mass E F2O 6 2 Argon has three isotopes with relative atomic masses of 36.0, 38.0 and 40.0. Given that the relative atomic mass of naturally occurring argon is 39.95, which of the following statements must be correct? A B C D E 3 40 Ar is less abundant than 38Ar. 40 Ar is more abundant than either 36Ar or 38Ar. 38 Ar is more abundant than 36Ar. 36 Ar is more abundant than 40Ar. 7 Another isotope of lesser mass must exist. An incomplete equation describing the nuclear decay of boron-9 is given below. How many neutrons or protons are also produced? 9 5B 4 Which of the following has a linear geometry? → 8 4 Be + 8 ? Which of the following elements has properties that most closely resemble those of calcium, Ca? A sodium, Na B potassium, K C magnesium, Mg D bromine, Br E krypton, Kr What is the formula of lead(II) nitrate? A Pb3N2 B Pb2N3 C Pb2NO3 D Pb(NO3)2 E PbNO3 Which of the following reacts with moisture in the air to form acid rain? A one neutron A sulfur trioxide, SO3 B one proton B nitrogen, N2 C one neutron and one proton D two protons C carbon dioxide, CO2 E two neutrons D methane, CH4 E ozone, O3 When 50.0 mL of water and 50.0 mL of ethanol are mixed, the total volume is found to be 96.5 mL. What is the density of this water-ethanol solution? A 1.78 g/mL B 0.895 g/mL C 0.211 g/mL D 3.45 mL E 0.927 g/mL 9 Densities, in g/mL: Water, 1.00 Ethanol , 0.789 2 / AVOGADRO EXAM © 2010 UNIVERSITY OF WATERLOO Which of the following is an example of chemical change? A boiling water B dissolving alcohol in water C heating copper metal D compressing a gas E rusting of iron 徐老湿留学 10 What is [Na+] in a solution obtained by mixing 50.0 mL of 0.100 mol/L NaNO3(aq) and 25.0 mL of 0.100 mol/L Na2CO3(aq)? A 0.133 mol L−1 B 0.200 mol L−1 C 0.300 mol L−1 D 0.167 mol L−1 E 0.125 mol L−1 2 SO2(g) + O2(g) → 2 SO3(g) What is the percentage yield of SO3 in this experiment? 11 What is the mass of 0.67 mol Na? A 29 mg B 15 g C 10 g D 23 g E 0.67 g A The density of the oxygen gas is greater than that of the carbon dioxide gas. B On average, the kinetic energy of a carbon dioxide molecule is greater than that of an oxygen molecule. C On average, a carbon dioxide molecule moves faster than does an oxygen molecule. D On average, the kinetic energy of carbon dioxide molecule is less than that of an oxygen molecule. The two samples contain the same number of molecules. 13 What is the net ionic equation for the reaction of Na2CO3(aq) and CaCl2(aq)? A B A 25% B 38% C 67% D 60% E 75% Molar masses (in g/mol) SO2 64.1 32.0 O2 SO3 96.2 Using the molar masses given, the “correct” answer is E. However, the molar mass given for SO3 is wrong. Question 14 was deleted. 15 What amount of C8H10O2N4 contains the same number of C atoms as 2 mol CO2? 12 One litre of oxygen gas is compared to one litre of carbon dioxide gas, both at 25 oC and 100 kPa. Which statement is correct? E 14 In an experiment, 16.0 g SO2 is treated with 6.0 g O2 and 18.0 g SO3 is obtained. A balanced chemical equation for the reaction is given below. Na+(aq) + Cl−(aq) → NaCl(s) A 2 mol B 8 mol C 4 mol D 0.25 mol E 0.5 mol 16 In which region of the periodic table would you find the elements of highest electronegativity? A top, left B top, right C near the middle D bottom, left E bottom, right 17 Which of the following has an odd-number of electrons? A NO3− B NO2 Na2CO3(aq) + CaCl2(aq) → 2 NaCl(aq) + CaCO3(s) C Ca+(aq) + CO3−(aq) → CaCO3(s) C N2O D Ca2+(aq) + CO32−(aq) → CaCO3(s) D NO+ E 2 Na+(aq) + CO32−(aq) → CO2(g) + Na2O(s) E NO2− © 2010 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 3 徐老湿留学 18 What is the correct electron arrangement for a 22 Consider the Lewis structure below for the CH3CCH scandium (Sc) atom? (The first number in each list molecule. H refers to the number of electrons in the first shell; the second number refers to the number of electrons in the second shell; and so on.) H C C C H A 2, 8, 9, 2 B 2, 8, 2, 8, 1 C 2, 8, 8, 3 D 10, 10, 1 E 4, 4, 4, 4, 1 H What is the maximum number of atoms that can lie in the same plane? 19 A 10.0 L cylinder containing neon gas with a measured pressure of 550 kPa at 298 K is connected through a valve to a 2.50 L cylinder containing 275 kPa of helium gas at 298 K. The valve is opened and the gases mix with no change in temperature. What is the final total pressure in the system? A three B four C five D six E seven A 277 kPa 23 The following ions all have the same number of electrons. B 326 kPa O2−, F−, Na+, Mg2+ C 413 kPa D 495 kPa E 599 kPa In which of following lists are these ions arranged in order of increasing radius (from smallest to largest)? 20 What is the H-N-H angle in the NH3 molecule? Choose the closest value. A O2− < F− < Na+ < Mg2+ B Mg2+ < Na+ < F− < O2− C Na+ < Mg2+ < O2− < F− A 45o D Mg2+ < Na+ < O2− < F− B 90o E F− < O2− < Na+ < Mg2+ C 109o D 120o E 180o 24 Which of the following is not a Bronsted-Lowry conjugate acid-base pair? 21 Which of the following molecules has the strongest carbon-carbon bond? A ethanol, CH3CH2OH B ethanoic acid, CH3CO2H C ethane, C2H6 D ethene, C2H4 E ethyne, C2H2 4 / AVOGADRO EXAM © 2010 UNIVERSITY OF WATERLOO A NH3 and NH2− B OH− and O2− C H3O+ and OH− D HCl and Cl− E NH4+ and NH3 徐老湿留学 25 A 0.350 g sample of acid HX requires 25.4 mL of 0.140 mol/L NaOH(aq) for complete reaction. What is the molar mass of the acid? A 29 In March of this year, the International Union of Pure and Applied Chemistry (IUPAC) officially approved the name and atomic symbol (Cn) for element 112. What is the official name of element 112? 42.3 g/mol A copernicium B 68.4 g/mol B californium C 98.4 g/mol C cupenium D 121 g/mol D cernium E 84.6 g/mol E cuternium o 26 What is the density of carbon dioxide gas at 0.00 C and 101.3 kPa? A 1.96 g/L B 0.0446 g/L C 22.4 g/L D 44.6 g/L E 0.509 g/L 27 An element M forms an ion M3+. The atom M and the ion M3+ have the same 30 Element 114 would be placed directly below lead (element 82). At the present time, nuclear scientists have managed to synthesize only a few atoms of element 114 at any one time and thus, the physical appearance of a larger sample is not yet known. Based on its position in the periodic table, element 114 is most likely to be a A reddish-brown volatile liquid B a pale yellow green gas C a colourless crystal D a gray-silvery metal E a black powdery solid A number of protons B number of electrons C radius D ionization energy A vinegar E chemical properties B soap C bleach D window cleaner E drain cleaner 31 Sodium hydroxide, NaOH, is most likely found in which household product? 28 Methanoic acid, HCOOH, is a weak electrolyte. In a solution prepared by dissolving 0.10 mol HCOOH in water to make 1.0 L of solution, approximately 4.1% of the HCOOH molecules ionize. What is the pH of this solution? A 0.61 B 1.39 C 2.39 D 4.10 E 6.10 © 2010 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 5 徐老湿留学 32 A balloon was filled with helium gas to a volume of 3.0 L on a day when the atmospheric pressure was 101 kPa and the temperature was 31 oC. The following day, the atmospheric pressure and temperature were measured as 98.3 kPa and 33 oC, respectively. The volume of the balloon had not changed. Which of the following statements is consistent with these data? A B Based on the changes in pressure and temperature that occurred, the volume of the balloon would not be expected to change. The balloon absorbed some air from the atmosphere. C Some helium gas leaked out of the balloon. D Helium atoms in the balloon lost energy to the surroundings. E 35 Compared to a chlorine atom, a sodium atom has a larger Based on the changes in pressure and temperature that occurred, the volume of the balloon should have decreased. 33 To prepare exactly 250 mL of 0.10 mol/L HCl(aq) starting from 1.0 L of 0.20 mol/L HCl(aq), one should A slowly add exactly 125 mL of 0.20 mol/L HCl(aq) to exactly 125 mL of water. B slowly add exactly 125 mL of 0.20 mol/L HCl(aq) to about 100 mL of water and then dilute with water to a total volume of 250 mL. A radius B mass C number of electrons D ionization energy E electronegativity 36 Which of the following bonds has the greatest ionic character? A C−H B O−H C O−F D H−F E C−O 37 A compound is found to be 85.62% carbon by mass and 14.38% hydrogen. What is the simplest formula of this compound? A CH B CH2 evaporate 750 mL of water from 1.0 L of 0.20 mol/L HCl(aq). C CH3 D CH4 D slowly add exactly 125 mL of water to exactly 125 mL of 0.20 mol/L HCl(aq). E C3H4 E add 750 mL of 0.10 mol/L NaOH to 1.0 L of 0.20 mol/L HCl(aq). C 34 Which of the following dilute solutions would allow a chemist to distinguish between dilute solutions of NaCl(aq) and NaNO3(aq)? A NaOH(aq) B HCl(aq) C NH3(aq) D H2SO4(aq) E AgNO3(aq) For question 33, the intended answer was “B”, but the volume of water was mistakenly given as 200 mL when 100 mL is what was intended. Question 33 was deleted. Answer “A” is not the correct answer because 125 mL of HCl(aq) and 125 mL of water may not give exactly 250 mL of solution because volumes are not exactly additive. See question 4 for an extreme example. 38 Mercury(II) sulfide, HgS, is practically insoluble in pure water. Its solubility at 25 oC is probably no more than 3×10−25 g/L. Of the following quantities of pure water, which is the smallest quantity that could be used to make a saturated solution of HgS? A 20,000 L B 1000 L C 10,000 L D 2000 L E 200 L 6 / AVOGADRO EXAM © 2010 UNIVERSITY OF WATERLOO Molar masses (in g/mol) Hg 200.6 32.07 S 徐老湿留学 39 What is the pH of a solution prepared by mixing 50.0 mL of 0.010 mol/L HCl(aq) and 50.0 mL of 0.010 mol/L Ca(OH)2(aq)? Assume the temperature is 25 oC. A 2.00 B 2.30 C 7.00 D 11.70 E 12.00 Kw = 1.0×10−14 at 25 oC 40 Consider the Lewis structure below. What is the charge on this molecule or ion? F A −2 B −1 C 0 D +1 E +2 Br F © 2010 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 7 徐老湿留学 DATA SHEET AVOGADRO EXAM 2010 DETACH CAREFULLY 1 1A 1 H 1.008 3 Li 6.941 11 Na 22.99 19 K 39.10 37 Rb 85.47 55 Cs 132.9 87 Fr (223) 2 2A 4 Be 9.012 12 Mg 3 4 24.31 3B 4B 22 21 20 Ti Sc Ca 40.08 44.96 47.88 38 39 40 Sr Y Zr 87.62 88.91 91.22 57-71 72 56 La-Lu Hf Ba 178.5 137.3 88 89-103 104 Ra Ac-Lr Rf 226 57 La 138.9 89 Ac 227. 58 Ce 140.1 90 Th 232.0 5 5B 23 V 50.94 41 Nb 92.91 73 Ta 180.9 105 Db 59 Pr 140.9 91 Pa 231.0 6 6B 24 Cr 52.00 42 Mo 95.94 74 W 183.9 106 Sg 60 Nd 144.2 92 U 238.0 7 7B 25 Mn 54.94 43 Tc (98) 75 Re 186.2 107 Bh 61 Pm (145) 93 Np 237.0 8 26 Fe 55.85 44 Ru 101.1 76 Os 190.2 108 Hs 9 8B 27 Co 58.93 45 Rh 102.9 77 Ir 192.2 109 Mt 10 28 Ni 58.69 46 Pd 106.4 78 Pt 195.1 110 Ds 64 63 62 Gd Eu Sm 150.4 152.00 157.3 94 95 96 Pu Am Cm (244) (243) (247) 11 1B 29 Cu 63.55 47 Ag 107.9 79 Au 197.0 111 Sg 65 Tb 158.9 97 Bk (247) 12 2B 30 Zn 65.38 48 Cd 112.4 80 Hg 200.6 112 Cn 66 Dy 162.5 98 Cf (251) 13 3A 5 B 10.81 13 Al 26.98 31 Ga 69.72 49 In 114.8 81 Tl 204.4 67 Ho 164.9 99 Es (252) 14 4A 6 C 12.01 14 Si 28.09 32 Ge 72.59 50 Sn 118.7 82 Pb 207.2 68 Er 167.3 100 Fm (257) 15 5A 7 N 14.01 15 P 30.97 33 As 74.92 51 Sb 121.8 83 Bi 209.0 69 Tm 168.9 101 Md (258) Constants: Conversion factors: NA = 6.022 1023 mol1 1 atm = 101.325 kPa = 760 torr R = 1 = 8.3145 kPa L K mol = 8.3145 J K1 mol1 Kw = F 0.082058 atm L K1 mol1 = 16 6A 8 O 16.00 16 S 32.07 34 Se 78.96 52 Te 127.6 84 Po (209) 70 Yb 173.0 102 No (259) 17 7A 9 F 19.00 17 Cl 35.45 35 Br 79.90 53 I 126.9 85 At (210) 71 Lu 175.0 103 Lr (260) = 760 mm Hg o 0 C = 273.15 K 1 1.0×10−14 (at 298 K) 96 485 C mol−1 Equations: PV = nRT k t1/2 = 0.693 pH = pKa + log ( [base] / [acid] ) 8 / AVOGADRO EXAM © 2010 UNIVERSITY OF WATERLOO x b b 2 4ac 2a 18 8A 2 He 4.003 10 Ne 20.18 18 Ar 39.95 36 Kr 83.80 54 Xe 131.3 86 Rn (222) 徐老湿留学 AVOGADRO EXAM 2011 UNIVERSITY OF WATERLOO DEPARTMENT OF CHEMISTRY 19 MAY 2011 TIME: 75 MINUTES This exam is being written by several thousand students. Please be sure that you follow the instructions below. We'll send your teacher a report on your performance. Top performers are eligible for a prize. The names of the top 200 students will be published in the September issue of Chem 13 News. 1. Print your name here: 2. Print your school name and city on your STUDENT RESPONSE sheet. 3. Select, and enter on the STUDENT RESPONSE sheet, one of the following CODE numbers: Code 1 Ontario, now studying Grade 11 Chemistry in a nonsemestered school Code 2 Ontario, now studying Grade 11 Chemistry in a semestered school Code 3 Ontario, Grade 11 Chemistry already completed Code 4 Any other Ontario student Code 5 Manitoba or Saskatchewan high school student Code 6 Québec high school student Code 7 Code 8 not used Alberta or British Columbia high school student Code 9 New Brunswick, Newfoundland, Nova Scotia, or Prince Edward Island high school student Code 10 Northwest Territories, Nunavut, or Yukon high school student 4. Print your name (last name, first name and optional middle initial) on the STUDENT RESPONSE sheet. Also fill in the corresponding circles below your printed name. 5. Carefully detach the last page. It is the datasheet. 6. Now answer the exam questions. Questions are not in order of difficulty. Indicate your choice on the STUDENT RESPONSE sheet by marking one letter beside the question number. • Mark only one answer for each question. • Questions are all of the same value. • There is a penalty (1/4 off) for each incorrect answer, but no penalty if you do not answer. 7. Take care that you make firm, black pencil marks, just filling the oval. Be careful that any erasures are complete—make the sheet white again. Code 11 High school student outside Canada Code 12 Teacher Carefully detach the last page. It is the Data Sheet. 徐老湿留学 1 Iodine-131 is a radioactive isotope used to treat hyperthyroidism (an overactive thyroid gland) and thyroid cancer. How many protons, neutrons and electrons are there in a single atom of iodine-131? 2 A 131 protons, 131 neutrons, 131 electrons B 53 protons, 78 neutrons, 53 electrons C 78 protons, 53 neutrons, 78 electrons D 53 protons, 131 neutrons, 53 electrons E 78 protons, 131 neutrons, 78 electrons 4 A student prepared the following graph to illustrate one aspect of ideal gas behaviour. However, he forgot to label the axes. Which of the following graphs could it be? Note: In the responses below, the symbols have their usual meanings: P is pressure; V is volume; T is kelvin temperature; n is amount in moles. Data are given below for the hypothetical element avogadrium, symbol Av. What is the average atomic weight of avogadrium? Relative weight 58.017 u 60.154 u Isotope Av-58 Av-60 3 5 A 58.79 u B 59.09 u C 58.55 u D 59.38 u E 59.62 u Fractional abundance 36.02% 63.98% 6 H2(g) → 2 H(g) + energy B Na(g) + e → Na (g) + energy C Mg(g) + energy → Mg (g) + 2e D Cu(s) + energy → Cu(l) E Na (g) + Cl (g) → NaCl(s) + energy − + three bonding pairs B three bonding pairs and one unshared pair C three bonding pairs and two unshared pairs D four bonding pairs and two unshared pairs E six bonding pairs C PV versus T, with n held constant D P versus V, with n and T held constant E PV/T versus P, with n held constant B RbCl C C(diamond) D Cu E IBr 7 How many electron pairs are there around the S atom − in the SF3 ion? A T versus n, with P and V held constant Cl2 − − B A − 2+ P versus T, with n and V held constant Which substance, in the solid state, is likely to have the following characteristics: hard; brittle; soluble in water; high melting point? Which of the following equations is not correct? A A 2 / AVOGADRO EXAM © 2011 UNIVERSITY OF WATERLOO The mass of a sample is measured as 0.03050 g. How many significant figures are there in this quantity? A two B three C four D five E six 徐老湿留学 8 9 Graphite is best described as A a hard, white solid 12 How many grams of B2H6 can be made starting with 5.00 g LiAlH4 and excess BF3, according to the following reaction? B a soft, white solid 3 LiAlH4 + 4 BF3 → 3 LiF + 3 AlF3 + 2 B2H6 C a soft, black solid D a hard, silvery solid E a yellowish liquid According to the World Health Organization, the development of methods for the disinfection of drinking water is considered one of the major achievements of modern times. Which of the following substances has been widely used to disinfect drinking water? A 1.85 g B 2.43 g C 3.65 g D 5.47 g E 7.29 g 13 An isotope of a particular element has a mass number of 208 and it has 46 more neutrons than protons. What is the element? A NaF A mercury, Hg B O2 B polonium, Po C Cl2 C lead, Pb D CO2 D bismuth, Bi E HCl E thallium, Tl 10 By the addition of water, 40.0 mL of 8.0 mol/L HI is diluted to 160.0 mL. What is the molar concentration of HI after dilution? 14 The covalent radius of hydrogen is 74 pm. Assume that hydrogen atoms could be arranged side-by-side in a single line, as suggested in the diagram below. What is the mass of a line of hydrogen atoms that is exactly 10 cm long? A 0.50 mol/L B 1.0 mol/L A 7.3×10 C 1.6 mol/L B 1.1×10 D 2.0 mol/L C 2.3×10 E 4.0 mol/L D 1.2×10 E 7.4×10 11 Which of the following substances does not produce ions when it is added to water? −10 −15 −15 −21 −11 g g 10 cm g g g 15 What is the H-C-H angle in the ethene molecule, C2H4? Choose the closest value. A sodium metal, Na B ethanol, CH3CH2OH A 45 C citric acid, C6H8O7 B 90 D carbon dioxide, CO2 C 109 D 120 E potassium nitrate, KNO3 E 180 o o o o o © 2011 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 3 徐老湿留学 16 A process for producing iron, Fe, is based on the following reactions. 20 Which of the following Lewis structures is incorrect? 2 C(g) + O2(g) → 2 CO(g) Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g) 19 kg B 43 kg C 50 kg D 75 kg E 170 kg H A 2 What mass of O2 is required to produce 1.0×10 kg Fe? A H H C O H F B H C Cl P F F 17 To which one of these pairs of elements does the term metalloids apply most fittingly apply? A potassium and strontium B nickel and silver C lithium and beryllium D sulfur and bromine E boron and silicon C C O − H H D B H H − O 18 Which of the following statements is true? E A Silicon conducts electricity better than aluminum. B Sulfur is more electronegative than chlorine. C The +1 oxidation state is common for sodium but not for aluminum. D The ionic radius of Cl is greater than that of S . E The atomic radius of aluminum is greater than that of sodium. − N O O 2− 21 The following equation represents a fission reaction in which an isotope of uranium is bombarded with neutrons. What must be the value of x in order to balance the equation? 1 0 n + 19 Which of the following molecules has the longest bond? A 0 A I2 B 1 B IBr C 2 C ICl D 3 D Cl2 E 4 E Br2 4 / AVOGADRO EXAM © 2011 UNIVERSITY OF WATERLOO 235 92 U → 141 56 Ba + 92 36 Kr 1 + x 0n 徐老湿留学 + 22 The concentration of H in stomach acid is about a million times greater than it is in pure water. What is o the approximate pH of stomach acid at 25 C? A 1.0 B 1.5 C 2.0 D 3.0 E 5.5 23 The first six ionization energies of a particular element are shown in the graph below. To which group of the periodic table does this element belong? IE(6) Energy 25 A 10.0 L gas cylinder contains neon gas with a measured pressure of 65.0 kPa at 315 K. The 10.0 L cylinder is then connected to an empty cylinder of unknown volume, and the neon gas expands to fill both cylinders. If the final pressure is found to be 46.3 kPa at 315 K, then what is the volume of the second cylinder? A 4.04 L B 13.0 L C 14.0 L D 1.87 L E 7.12 L 26 Which of the following atoms, in their ground electronic states, does not have a half-filled subshell? A Ga B H C Mn D K E As IE(5) IE(2) IE(1) 1 2 IE(3) 3 IE(4) 4 5 6 27 What is the formula of the stable compound that contains only magnesium and phosphate ions? number of electrons removed A Mg2(PO4)3 B MgPO4 C Mg(PO4)3 group 14 D Mg3PO4 group 15 E Mg3(PO4)2 A group1 B group 2 C group 13 D E 24 Which of the following produces the greatest mass of metal upon reduction with one mole of electrons? 3+ A Al B Cu C Pt D Mg E Ag 2+ 2+ 2+ + 28 Suppose 10.0 mL of a 1.0 mol/L solution of HCl is diluted with water to a final volume of 1.0 L. What happened to the pH of the solution? A The pH decreases by 10 units. B The pH increases by 10 units. C The pH decreases by 2 units. D The pH increases by 2 units. E The pH changes by less than 1 unit. © 2011 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 5 徐老湿留学 − 29 How many moles of Br are in 250.0 mL of a solution that is 0.148 mol/L with respect to NaBr and 0.212 mol/L with respect to CaBr2? 33 A sulfuric acid (H2SO4) solution has a density of 1.29 g/mL and it is 38% by mass H2SO4. What is the molar concentration of this solution? A 0.572 mol A 0.38 mol/L B 0.090 mol B 0.49 mol/L C 0.143 mol C 0.98 mol/L D 0.360 mol D 5.0 mol/L E 0.427 mol E 10.0 mol/L Molar masses, in g/mol H, 1.008 O, 16.00 S, 32.07 30 Select the one correct or the one incorrect statement. A Ionization energies generally decrease from left to right across a row in the periodic table. B Ionization energies generally decrease from top to bottom in a vertical group of the periodic table. C Atomic sizes generally increase from top to bottom in a vertical group of the periodic table. D The atomic radius generally decreases from left to right across a row in the periodic table. E 34 In the structure below, X represents an unidentified element. 2− O O 31 Deviations from ideal gas behaviour are most evident for a gas at high temperature and high pressure B low temperature and low pressure C high temperature and low pressure D low temperature and high pressure E high temperature in a large volume O What is the possible identity of X? The second ionization energy of an element is always larger than the first ionization energy. A X A carbon, C B nitrogen, N C sulfur, S D phosphorus, P E chlorine, Cl 35 A particular airship (a zeppelin or blimp) uses C8H16 as fuel. C8H16 + 12 O2 → 8 CO2 + 8 H2O How many moles of CO2 are in the cylinder? To counterbalance the weight loss of fuel used in the operation of the airship, part of the water contained in the exhaust gases must be condensed and retained. The remainder of the water and the CO2 are vented to the atmosphere. If the mass of water retained exactly offsets the mass of fuel burned, what percentage of the water is retained? A 0.203 mol A 22% B 0.144 mol B 39% C 0.113 mol C 11% D 0.261 mol D 61% E 0.355 mol E 78% 32 The partial pressures of three gases in a 5.00 L o cylinder at 1000 C are as follows. CO2: 239 kPa H2: 72 kPa H2O: 106 kPa 6 / AVOGADRO EXAM © 2011 UNIVERSITY OF WATERLOO 徐老湿留学 36 In the following structures for four different carbonhydrogen compounds, a carbon atom exists wherever a line ends or meets another line, and the number of H atoms needed to complete each carbon atom’s four bonds are assumed to be present. (1) (2) (3) 39 To a weighed, clean and dry 1.000 L volumetric flask is added some pure NH4Cl. The flask is reweighed. Then distilled water is added to dissolve the NH4Cl, and finally enough water is added, with stirring, to bring the solution to the 1.000 L mark. The flask is reweighed. Data are shown below. (4) Mass of clean and dry 1.000 L flask: 224.3 g Mass of flask plus NH4Cl: 280.1 g Mass of flask plus NH4Cl plus water: 1239.5 g Which two compounds are isomers with the formula C6H10? Which of the following statements concerning the resulting solution is correct? A (1) and (2) A The molar concentration of NH4Cl is 5.23 mol/L. B (2) and (3) B The density of the solution is 1.24 g/mL. C (3) and (4) C The solution is 22.6% NH4Cl by mass. D (2) and (4) D All of A, B and C are true. E (1) and (3) E None of A, B and C are true. 37 Refer to the information and structures given in question 36. In which compound are all the carboncarbon bond lengths the same? A (1) B (2) C (3) D (4) E none of the above 40 One of two identical balloons contained carbon −1 dioxide (CO2, 44 g mol ) and the other contained −1 hydrogen (H2, 2.0 g mol ). If it took 24 hours for all of the H2 to escape from its balloon, how long did it take for all of the CO2 to escape? (Choose the closest value.) Hint: For a sample of gas at a fixed temperature T, the average speed of molecules is inversely 1/2 proportional to m , where m is the molecular mass. 38 In a well-insulated container, an endothermic chemical reaction takes place. When the reaction is done, the temperature of the contents will be A higher than before the reaction began B higher or lower than at the start of the reaction, depending on the heat capacities of the substances involved C the same as before the reaction began D lower than before the reaction began E independent of the heat capacities of the substances involved A 530 hours B 110 hours C 230 hours D 1 hour E 5 hours © 2011 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 7 徐老湿留学 DATA SHEET AVOGADRO EXAM 2011 DETACH CAREFULLY 1 1A 1 H 1.008 3 Li 6.941 11 Na 22.99 19 K 39.10 37 Rb 85.47 55 Cs 132.9 87 Fr (223) 2 2A 4 Be 9.012 12 Mg 24.31 20 Ca 40.08 38 Sr 87.62 56 Ba 137.3 88 Ra 226 3 4 3B 4B 21 22 Sc Ti 44.96 47.88 39 40 Y Zr 88.91 91.22 57-71 72 La-Lu Hf 178.5 89-103 104 Ac-Lr Rf 57 La 138.9 89 Ac (227) 58 Ce 140.1 90 Th 232.0 5 5B 23 V 50.94 41 Nb 92.91 73 Ta 180.9 105 Db 59 Pr 140.9 91 Pa 231.0 6 6B 24 Cr 52.00 42 Mo 95.94 74 W 183.9 106 Sg 60 Nd 144.2 92 U 238.0 7 7B 25 Mn 54.94 43 Tc (98) 75 Re 186.2 107 Bh 61 Pm (145) 93 Np 237.0 8 ← 26 Fe 55.85 44 Ru 101.1 76 Os 190.2 108 Hs 9 8B 27 Co 58.93 45 Rh 102.9 77 Ir 192.2 109 Mt 10 → 28 Ni 58.69 46 Pd 106.4 78 Pt 195.1 110 Ds 62 63 64 Sm Eu Gd 150.4 152.00 157.3 94 95 96 Pu Am Cm (244) (243) (247) Constants: 23 = 0.082058 atm L K−1 mol−1 −1 67 Ho 164.9 99 Es (252) 68 Er 167.3 100 Fm (257) 69 Tm 168.9 101 Md (258) 16 6A 8 O 16.00 16 S 32.07 34 Se 78.96 52 Te 127.6 84 Po (209) 70 Yb 173.0 102 No (259) 17 7A 9 F 19.00 17 Cl 35.45 35 Br 79.90 53 I 126.9 85 At (210) 71 Lu 175.0 103 Lr (260) = 8.3145 J K−1 mol−1 −14 Kw = 1.0×10 F 96 485 C mol = 760 mm Hg o 0 C = 273.15 K −1 8.3145 kPa L K mol Equations: 66 Dy 162.5 98 Cf (251) 15 5A 7 N 14.01 15 P 30.97 33 As 74.92 51 Sb 121.8 83 Bi 209.0 1 atm = 101.325 kPa = 760 torr = = 65 Tb 158.9 97 Bk (247) 12 2B 30 Zn 65.38 48 Cd 112.4 80 Hg 200.6 112 Cn 14 4A 6 C 12.01 14 Si 28.09 32 Ge 72.59 50 Sn 118.7 82 Pb 207.2 Conversion factors: NA = 6.022 × 10 mol−1 R 11 1B 29 Cu 63.55 47 Ag 107.9 79 Au 197.0 111 Sg 13 3A 5 B 10.81 13 Al 26.98 31 Ga 69.72 49 In 114.8 81 Tl 204.4 (at 298 K) −1 PV = nRT k t1/2 = 0.693 pH = pKa + log ( [base] / [acid] ) 8 / AVOGADRO EXAM © 2011 UNIVERSITY OF WATERLOO x= −b ± b 2 − 4ac 2a 18 8A 2 He 4.003 10 Ne 20.18 18 Ar 39.95 36 Kr 83.80 54 Xe 131.3 86 Rn (222) 徐老湿留学 AVOGADRO EXAM 2012 UNIVERSITY OF WATERLOO DEPARTMENT OF CHEMISTRY 17 MAY 2012 TIME: 75 MINUTES This exam is being written by several thousand students. Please be sure that you follow the instructions below. We'll send your teacher a report on your performance. Top performers are eligible for a prize. The names of the top 200 students will be published in the September issue of Chem 13 News. 1. Print your name here: 2. Print your school name and city on your STUDENT RESPONSE sheet. 3. Select, and enter on the STUDENT RESPONSE sheet, one of the following CODE numbers: Code 1 Ontario, now studying Grade 11 Chemistry in a nonsemestered school Code 2 Ontario, now studying Grade 11 Chemistry in a semestered school Code 3 Ontario, Grade 11 Chemistry already completed Code 4 Any other Ontario student Code 5 Manitoba or Saskatchewan high school student Code 6 Québec high school student Code 7 Code 8 not used Alberta or British Columbia high school student Code 9 New Brunswick, Newfoundland, Nova Scotia, or Prince Edward Island high school student Code 10 Northwest Territories, Nunavut, or Yukon high school student 4. Print your name (last name, first name and optional middle initial) on the STUDENT RESPONSE sheet. Also fill in the corresponding circles below your printed name. 5. Carefully detach the last page. It is the datasheet. 6. Now answer the exam questions. Questions are not in order of difficulty. Indicate your choice on the STUDENT RESPONSE sheet by marking one letter beside the question number. • Mark only one answer for each question. • Questions are all of the same value. • There is a penalty (1/4 off) for each incorrect answer, but no penalty if you do not answer. 7. Take care that you make firm, black pencil marks, just filling the oval. Be careful that any erasures are complete—make the sheet white again. Code 11 High school student outside Canada Code 12 Teacher Carefully detach the last page. It is the Data Sheet. 徐老湿留学 1 How many protons are there in a single 2 A 14 B 16 C 18 D 19 E 33 4 ion? 5 What volume does 3.20 grams of methane gas, o CH4(g), occupy at 0 C and 101.325 kPa? Choose the closest answer. A 1.12 L B 2.24 L C 3.40 L D 4.48 L E 22.4 L + The combination of hydronium (H3O ) ions and − hydroxide (OH ) ions to form water molecules is called A 3 35 2 − 16 S 6 Which of the following substances has a normal o boiling point higher than 500 C? precipitation B electrolysis C neutralization D hydrogenation E hydrolysis Which of the following occurs when Na2O is added to water? 7 A propane, C3H8 B bromine, Br2 C mercury, Hg D sodium chloride, NaCl E sulfuric acid, H2SO4 −1 Elemental gold, Au(s), has a density of 19.3 g mL at 25°C. What is the volume of 42.5 grams of Au(s)? A The water freezes. A 0.454 mL B A gas is released. B 2.20 mL C A black precipitate is formed. C 23.2 mL D Heat is liberated. D 61.8 mL E A white precipitate is formed. E 820 mL Isotopes differ in A atomic number B number of neutrons C number of electrons D number of protons E nuclear charge 8 2 / AVOGADRO EXAM © 2012 UNIVERSITY OF WATERLOO o At 25 C and 101.325 kPa, the element Sn is A a liquid with a low vapour pressure B a reactive, colourless gas C a liquid with a high vapour pressure D a solid that is a poor conductor of heat E a solid that is a good conductor of electricity 徐老湿留学 9 o A 10.0 L container has a sample of O2(g) at 25 C and 51 kPa. A second 10.0 L container has a o sample of CH4(g), also at 25 C and 51 kPa. Assuming ideal gas behaviour, which of the following statements concerning these two samples is correct? (1) They contain the same number of molecules. (2) They have the same density. (3) The molecules in the two samples have the same average kinetic energy. A (1) and (2) B (2) and (3) C (1) and (3) D (1) only E (3) only 12 A solution contains H2O2 in water. Complete decomposition of the H2O2 in 170 g of this solution o yields 5.6 L of O2(g), measured at 0 C and 101.325 kPa. What is the percentage by mass of H2O2 in this solution? Choose the closest answer. A 10% B 20% C 5.0% D 3.0% E 1.0% 13 A handbook gives the specific heat of copper (Cu) −1 o −1 as 0.385 J g C . What is the specific heat −1 −1 expressed in J g K ? Choose the closest value. −1 105 J g B 0.385 J g C 1.41×10 D 2.60 J g E 9.51×10 −1 −1 10 What volume of 6.00 mol L HBr(aq) is required to −1 make 1.00 L of 2.40 mol L HBr(aq)? A 1.00 L B 0.600 L C 0.400 L D 0.200 L E 0.167 L −1 K A −3 −1 −3 −1 K −1 Jg −1 K −1 K −1 Jg −1 K 14 Element X forms the stable compounds XS, XSO4 and X(NO3)3. Which of the following could X represent? 11 The specific heats of gold and copper are 0.13 and −1 o −1 0.39 J g C , respectively. If 1.0 g samples of each, o initially at 25 C, are placed in the same beaker of hot water, A the copper will have the highest final temperature B the gold will absorb the greatest quantity of heat C the copper will absorb the greatest quantity of heat A carbon B magnesium C sodium D zinc E iron 15 Which of the following has a planar, triangular shape? − A NO3 D the gold will have the highest final temperature B CO2 E the temperature change for the copper will be about three times that of the gold C NH3 D BeH2 E SO3 2− © 2012 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 3 徐老湿留学 16 What is the minimum mass of oxygen gas required to react with exactly 20 grams of hydrogen gas, assuming these gases react to form water? Choose the closest answer. 20 What are the most probable products of the combustion of CH3CH2SH in oxygen? A CH4 and H2S A 20 g B CO2 and H2S B 40 g C CO2, H2O and SO2 C 80 g D CO2, H2O and H2SO4 D 160 g E CH4, H2O and SO2 E 320 g 21 How many moles of Cl2 are required to oxidize exactly 2+ 3+ one mole of Fe to one mole of Fe ? 17 Typically, a binary salt may be formed between A an s-block cation and a d-block anion B a p-block cation and an s-block anion C a d-block cation and an s-block anion D a p-block cation and a d-block anion E an s-block cation and a p-block anion A 0.5 moles B 1 mole C 1.5 moles D 2 moles E 3 moles −1 18 Where in the periodic table does one find the atoms with the smallest atomic radius? A upper left B upper right C lower left D lower right E in the first long period (fourth row) 19 Which of the following pairs of substances are allotropes? A CH3CH2OH and CH3OCH3 B Fe(NO3)2 and Fe(NO3)3 C NaCl and KCl D O2 and O3 E 234 U and 22 The pH of a 0.10 mol L aqueous solution is 5.1. Which of the following might be the solute? A NaCl B HCl C HNO3 D NH3 E NH4Cl 23 The third ionization energy of an element, X, is the energy required to A remove one mole of electrons from one mole of X atoms B remove three moles of electrons from one mole of X atoms C remove one mole of electrons from one mole of 3+ X ions D remove one mole of electrons from one mole of 2+ X ions E add three moles of electrons to one mole of X atoms 238 U 4 / AVOGADRO EXAM © 2012 UNIVERSITY OF WATERLOO 徐老湿留学 28 What of the following is named copper (II) chloride? 24 What is the oxidation state of sulfur in H2S2O6? A +4 B +5 C +6 D +7 E +10 25 A 1.0 L sample of N2(g) has a pressure of exactly 100 kPa. A 2.0 L sample of O2(g) has a pressure of 50 kPa at the same temperature. The samples are mixed and forced into a 1.0 L container. Assuming that no reaction occurs and that the temperature remains constant, what is the final pressure of the mixture? A CuCl2 B Cu2Cl C (CuCl)2 D CuCl E Cu2Cl2 29 What mass of Na2CO3 is needed to make 5.00 L of a + −1 solution having [Na ] = 0.100 mol L ? A 0.500 g B 5.30 g A 25 kPa C 10.6 g B 50 kPa D 26.5 g C 100 kPa E 53.0 g D 150 kPa E 200 kPa 30 Which of the following statements concerning the reaction below is true? Mg + CuSO4 → MgSO4 + Cu 26 Which of the following atoms has the greatest number of unpaired electrons in its ground electronic state? A Magnesium is reduced. B Magnesium is the oxidizing agent. Si C Sulfur is oxidized. D Co D Sulfur is reduced. E Zn E Copper sulfate is the oxidizing agent. A Sc B Al C −1 27 If 1.0 mol L NaX(aq) contains 7.4% solute by mass, what is the molar mass of X? Choose the closest answer. Assume the density of this solution is approximately equal to that of water, 1.0 g/mL. A 31 The noble gas atoms show only a limited tendency to form covalent bonds with other atoms. Which of the following pairs of atoms show the greatest tendency to form a covalent bond? −1 17 g mol −1 B 51 g mol C 74 g mol D 98 g mol E 120 g mol −1 −1 −1 A neon and fluorine B neon and iodine C xenon and fluorine D xenon and cesium E xenon and iodine © 2012 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 5 徐老湿留学 32 A gaseous mixture consists of 25% H2, 25% N2, 25% O2 and 25% Cl2 by mass. Which gas has the o highest partial pressure at 227 C and 101 kPa? Molar masses, −1 (in g mol ): 2.016 H2, 28.02 N2, 32.00 O2, Cl2, 70.90 A H2 B N2 C O2 D Cl2 E The partial pressures are equal. −1 35 When 0.100 L of 1.00 mol L HCl(aq) is mixed with −1 0.100 L of 1.00 mol L NaOH, the temperature of o the solution rises by 8.5 C. Assuming no heat loss to the container or the surroundings, what is the heat of reaction for the following reaction? (You may also assume that, for these aqueous solutions, the −1 density is about 1.0 g mL and the heat capacity is −1 o −1 about 4.2 J g C .) + −1 33 In an experiment,1.0 mol L HCl(aq) is added −1 millilitre-by-millilitre to 50.0 mL of 1.0 mol L NaOH(aq) until the total volume reaches 150.0 mL. Which of the following statements concerning this experiment is correct? A The pH increases approximately linearly with the volume of HCl added. B The pH decreases approximately linearly with the volume of HCl added. C Initially, the pH decreases approximately linearly with the volume of HCl added, and then decreases abruptly as the total volume approaches 50.0 mL. D E Initially, the pH increases approximately linearly with the volume of HCl added, and then increases abruptly as the total volume approaches 100.0 mL. A KO B K2O C KO2 D K2O3 E KO3 −1 A −4.8 kJ mol B −7.1 kJ mol C −18 kJ mol D −36 kJ mol E −71 kJ mol −1 −1 −1 −1 36 Which expression correctly represents a chemical reaction between calcium hydroxide and carbon dioxide? Initially, the pH decreases approximately linearly with the volume of HCl added, and then decreases abruptly as the total volume approaches 100.0 mL. 34 An oxide of potassium contains 45.0% oxygen by mass. What is the simplest formula of this oxide? − H (aq) + OH (aq) → H2O(l) A CaOH + CO2 → CaHCO2 B Ca(OH)2 + CO2 → CaCO3 + H2O C Ca(OH)2 + CO2 → CaHCO3 + H2O D 2 CaOH + 2 CO2 → 2 CaCO3 + H2O E Ca(OH)2 + 2 CO2 → Ca(CO3)2 + H2O 37 Which of the following pairs of atoms will form a bond with the greatest covalent character? 6 / AVOGADRO EXAM © 2012 UNIVERSITY OF WATERLOO A carbon and oxygen B hydrogen and oxygen C carbon and chlorine D hydrogen and chlorine E hydrogen and carbon 徐老湿留学 38 If an element X forms an oxide with the formula XO2, then what is the expected formula for the fluoride of element X? A XF B XF2 C XF3 D XF4 E X2F 39 A 0.9300 g sample of a mixture of NaCl and MgCl2 was dissolved in water. Addition of excess AgNO3(aq) caused all of the chloride ion to precipitate as AgCl(s). The dry precipitate weighed 2.676 g. What was the percentage by weight of NaCl in the original mixture? A between 0 and 19.9% B between 20.0 and 39.9% C between 40.0 and 59.9% D between 60.0 and 79.9% E between 80.0% and 100% Molar masses (in g mol−1): NaCl, 58.44 MgCl2, 95.21 AgCl, 143.35 40 If the Kelvin temperature of a gas increases by a factor of four, then the average speed of molecules A increases by a factor of four B decreases by a factor of four C increases by a factor of two D decreases by a factor of two E is unchanged © 2012 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 7 徐老湿留学 DATA SHEET AVOGADRO EXAM 2012 DETACH CAREFULLY 1 1A 1 H 1.008 3 Li 6.941 11 Na 22.99 19 K 39.10 37 Rb 85.47 55 Cs 132.9 87 Fr (223) 2 2A 4 Be 9.012 12 Mg 24.31 20 Ca 40.08 38 Sr 87.62 56 Ba 137.3 88 Ra 226 3 4 3B 4B 21 22 Sc Ti 44.96 47.88 39 40 Y Zr 88.91 91.22 57-71 72 La-Lu Hf 178.5 89-103 104 Ac-Lr Rf 57 La 138.9 89 Ac (227) 58 Ce 140.1 90 Th 232.0 5 5B 23 V 50.94 41 Nb 92.91 73 Ta 180.9 105 Db 59 Pr 140.9 91 Pa 231.0 6 6B 24 Cr 52.00 42 Mo 95.94 74 W 183.9 106 Sg 60 Nd 144.2 92 U 238.0 7 7B 25 Mn 54.94 43 Tc (98) 75 Re 186.2 107 Bh 61 Pm (145) 93 Np 237.0 8 ← 26 Fe 55.85 44 Ru 101.1 76 Os 190.2 108 Hs 9 8B 27 Co 58.93 45 Rh 102.9 77 Ir 192.2 109 Mt 10 → 28 Ni 58.69 46 Pd 106.4 78 Pt 195.1 110 Ds 62 63 64 Sm Eu Gd 150.4 152.00 157.3 94 95 96 Pu Am Cm (244) (243) (247) Constants: mol−1 6.022 × 10 R = 0.082058 atm L K−1 mol−1 = 8.3145 kPa L K−1 mol−1 = 8.3145 J K−1 mol−1 23 −14 Kw = 1.0×10 F 96 485 C mol Equations: 65 Tb 158.9 97 Bk (247) 12 2B 30 Zn 65.38 48 Cd 112.4 80 Hg 200.6 112 Cn 66 Dy 162.5 98 Cf (251) 67 Ho 164.9 99 Es (252) 14 4A 6 C 12.01 14 Si 28.09 32 Ge 72.59 50 Sn 118.7 82 Pb 207.2 68 Er 167.3 100 Fm (257) 15 5A 7 N 14.01 15 P 30.97 33 As 74.92 51 Sb 121.8 83 Bi 209.0 69 Tm 168.9 101 Md (258) 16 6A 8 O 16.00 16 S 32.07 34 Se 78.96 52 Te 127.6 84 Po (209) 70 Yb 173.0 102 No (259) 17 7A 9 F 19.00 17 Cl 35.45 35 Br 79.90 53 I 126.9 85 At (210) 71 Lu 175.0 103 Lr (260) Conversion factors: NA = = 11 1B 29 Cu 63.55 47 Ag 107.9 79 Au 197.0 111 Sg 13 3A 5 B 10.81 13 Al 26.98 31 Ga 69.72 49 In 114.8 81 Tl 204.4 1 atm = 101.325 kPa = 760 Torr = 760 mm Hg o 0 C = 273.15 K (at 298 K) −1 PV = nRT k t1/2 = 0.693 pH = pKa + log ( [base] / [acid] ) 8 / AVOGADRO EXAM © 2012 UNIVERSITY OF WATERLOO x= −b ± b 2 − 4ac 2a 18 8A 2 He 4.003 10 Ne 20.18 18 Ar 39.95 36 Kr 83.80 54 Xe 131.3 86 Rn (222) 徐老湿留学 AVOGADRO EXAM 2013 UNIVERSITY OF WATERLOO DEPARTMENT OF CHEMISTRY 16 MAY 2013 TIME: 75 MINUTES This exam is being written by several thousand students. Please be sure that you follow the instructions below. We'll send your teacher a report on your performance. Top performers are eligible for a prize. The names of the top 200 students will be published in the September issue of Chem 13 News. 1. Print your name here: 2. Print your school name and city on your STUDENT RESPONSE sheet. 3. Select, and enter on the STUDENT RESPONSE sheet, one of the following CODE numbers: Code 1 Ontario, now studying Grade 11 Chemistry in a nonsemestered school Code 2 Ontario, now studying Grade 11 Chemistry in a semestered school Code 3 Ontario, Grade 11 Chemistry already completed Code 4 Any other Ontario student Code 5 Manitoba or Saskatchewan high school student Code 6 Québec high school student Code 7 Code 8 not used Alberta or British Columbia high school student Code 9 New Brunswick, Newfoundland, Nova Scotia, or Prince Edward Island high school student Code 10 Northwest Territories, Nunavut, or Yukon high school student 4. Print your name (last name, first name and optional middle initial) on the STUDENT RESPONSE sheet. Also fill in the corresponding circles below your printed name. 5. Carefully detach the last page. It is the datasheet. 6. Now answer the exam questions. Questions are not in order of difficulty. Indicate your choice on the STUDENT RESPONSE sheet by marking one letter beside the question number. • Mark only one answer for each question. • Questions are all of the same value. • There is a penalty (1/4 off) for each incorrect answer, but no penalty if you do not answer. 7. Take care that you make firm, black pencil marks, just filling the oval. Be careful that any erasures are complete—make the sheet white again. Code 11 High school student outside Canada Code 12 Teacher Carefully detach the last page. It is the Data Sheet. 徐老湿留学 1 An ion having 18 electrons, 15 protons and 16 neutrons has a mass number of? 2 3 4 5 In which region of the periodic table would you find the elements of highest electronegativity? A 49 A upper left B 34 B upper right C 33 C middle D 31 D bottom left E 17 E bottom right Which of the following elements has the o greatest density at 25 C and 101 kPa? A cesium, Cs B radon, Rn C lead, Pb D carbon, C E iron, Fe 6 A HCl + H2O → H2 + HOCl B HCl + H2O → 2 H + OH + Cl C HCl + H2O → H3O + Cl D HCl + H2O → 3 H + O E HCl + H2O → 3 H + OCl + + + + − − − 2− − + Cl − A the same charge and about the same mass Common table sugar is a compound with the formula C12H22O11. How many oxygen atoms are present in one mole of C12H22O11? B no charge and a much greater mass A 6.02×10 C the opposite charge and much less mass B 6.62×10 24 D no charge and much less mass C 5.46×10 22 E the opposite charge and a much greater mass D 1.32×10 25 E 7.22×10 Compared to an electron, a neutron has 7 Which of the following most correctly represents the reaction between hydrochloric acid and water? 23 23 To which of the following elements does the term metalloid apply most fittingly? A hydrogen B lithium C beryllium D boron E mercury 8 2 / AVOGADRO EXAM © 2013 UNIVERSITY OF WATERLOO Which measurement is the most uncertain? A 0.10 ± 0.01 g B 2.00 ± 0.05 L C 1.00 ± 0.01 mm D 0.200 ± 0.001 mL E 1.000 ± 0.001 kg 徐老湿留学 9 A compound is 53% carbon and 47% oxygen by mass. What is the empirical formula of the compound? 12 According to the following equation, how many moles of CO2 can be produced from 10.0 g Fe2O3 and excess CO? 3 Fe2O3 + CO → 2 Fe3O4 + CO2 A CO2 B CO A 3.33 moles C C2O3 B 0.0209 moles D C3O2 C 0.918 moles E C53O47 D 1.00 moles E 0.357 moles 10 A one litre sample of nitrogen gas is compared to a o one litre sample of hydrogen gas, both at 25 C and 101 kPa. Which of the following statements is true? A Nitrogen and hydrogen molecules have the same average speed. B On average, nitrogen molecules move more slowly than the hydrogen molecules do. C Hydrogen molecules have a greater average kinetic energy than the nitrogen molecules do. D E On average, hydrogen molecules hit the walls of the container with more force than the nitrogen molecules do. On average, nitrogen molecules hit the walls of the container with more force than the hydrogen molecules do. 11 What is the correct electron arrangement for an arsenic (As) atom? (The first number in each list refers to the number of electrons in the first shell; the second number refers to the number of electrons in the second shell; and so on.) A 2, 8, 18, 5 B 10, 10, 3 C 2, 8, 2, 8, 2, 8, 2, 1 D 2, 6, 10, 14, 1 E 8, 8, 8, 8, 1 13 Which of the following is a weak electrolyte in water? A HNO3 B KOH C HF D HBr E NH4F −1 14 What is the minimum volume of 6.00 mol L H2SO4(aq) −1 required to neutralize 2.00 L of 2.25 mol L NaOH(aq)? 2 NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + 2 H2O(l) A 0.375 L B 0.667 L C 0.750 L D 1.50 L E 6.75 L 15 Which ion does not have the same shape as CH4? + A NH4 B BF4 C SO4 D PF4 E BrO4 − 2− − − © 2013 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 3 徐老湿留学 16 An element occurring in nature as a metal, such as silver or gold, is likely to A react readily with oxygen to form a protective coating 20 The following sequence of reactions is used in the preparation of sodium sulfate, Na2SO4.What is the minimum amount of O2 required to make 1.0 mole of Na2SO4? S + O2 → SO2 2 SO2 + O2 → 2 SO3 SO3 + H2O → H2SO4 2 NaOH + H2SO4 → Na2SO4 + 2 H2O B be at the high end of the activity series of metals C react readily with strong acids to release hydrogen gas D lose some of its valence electrons easily A 0.33 moles E undergo oxidation only with difficulty B 0.50 moles C 1.0 mole D 1.5 moles E 2.0 moles 17 Which of the following involves a chemical change? A crystallization B electrolysis C distillation D sublimation E vaporization 21 The chemical equation representing the decomposition of nitroglycerine, C3H5(NO3)3, is given below. 4 C3H5(NO3)3(s) → 12 CO2(g) + 6 N2(g) + O2(g) + 10 H2O(g) o What is the total volume of gas produced at 100 C and 2 atm from 454 grams of nitroglycerine? 18 When a sample of sugar, C12H22O11, is treated with concentrated H2SO4, a black product (carbon) is obtained. The action of concentrated H2SO4 on sugar illustrates the fact that H2SO4 is A 89.6 L B 111 L A a powerful dehydrating agent C 162 L B highly unstable D 222 L C a strong acid E 444 L D a strong oxidizing agent E a strong reducing agent 22 Consider the following unbalanced equation. (This question can be answered without balancing the equation.) 19 What is the oxidation state of chlorine in NaClO3? A +4 B +3 C +5 D −2 E −1 4 / AVOGADRO EXAM © 2013 UNIVERSITY OF WATERLOO As2S5 + HNO3 → H3AsO4 + H2SO4 + NO2 Which of the following statements is true? A As of As2S5 is oxidized. B N of HNO3 is reduced. C S of As2S5 is reduced. D As of As2S5 is reduced. E As2S5 is acting as an oxidizing agent. 徐老湿留学 27 A 0.480 L sample of “wet” hydrogen gas was collected over water at a barometric pressure of o 735.4 Torr and a temperature of 21.7 C. The vapour pressure of water at this temperature is 19.498 Torr. What is the volume of the “dry” hydrogen gas at STP? 23 If an element X forms the following stable compounds and ions, what is element X? CX2 − NX3 A beryllium, Be B carbon, C C fluorine, F D oxygen, O E hydrogen, H CaX 2− SX3 24 Which of the following statements is not correct? A The first ionization energy generally decreases from top to bottom within a group. B The atomic radius generally increases from top to bottom within a group. C The first ionization energy generally decreases from left to right across a period. D The second ionization energy of an atom is always greater than the first ionization energy. E The atomic radius generally decreases from left to right across a period. A 0.419 L B 0.468 L C 0.488 L D 0.522 L E 22.4 L 760 Torr = 1 atm o STP = 1 atm and 0 C 28 What mass of impure solid KOH is needed to make −1 up 1.20 L of 0.60 mol L KOH(aq)? Assume the impure KOH is 84% KOH by mass and 16% water. A 34.2 g B 40.4 g C 48.1 g D 87.0 g E 112 g −1 25 Which of the following atoms has more than two unpaired electrons in its ground electronic state? 29 In an experiment, 4 drops of 0.100 mol L CuSO4(aq) were added to 150.0 mL of (NH4)2S2O8 solution. What is the resulting concentration of CuSO4? Assume that 20 drops is equivalent to 1 mL. −4 A germanium, Ge A 1.67×10 B selenium, Se B 6.67×10 C scandium, Sc C 5.32×10 D nickel, Ni D 2.67×10 E iron, Fe E 1.33×10 26 Which of the following molecules has the shortest carbon-carbon bond? A CH3CH3 B −4 −4 −3 −4 −1 mol L −1 mol L -1 mol L −1 mol L −1 mol L 30 For a chemical reaction, the limiting reactant is the one that is A least stable CH2CH2 B most stable C C2H2 C most expensive D CH3COOH D still present after the reaction is complete E CH3CH2OH E completely used up © 2013 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 5 徐老湿留学 − 31 During the process K(g) → K (g) + e + A o 35 The pH of an aqueous solution at 25 C is 9.83. + What is the hydrogen ion concentration, [H ]? energy is released and the ion is larger than the atom B energy is absorbed and the ion is larger than the atom C energy is released but the atom and the ion have the same size D energy is absorbed and the ion is smaller than the atom E energy is released and the ion is smaller than the atom −1 A 9.8 mol L B 0.99 mol L C 2.28 mol L D 1.5×10 E 5.4×10 −1 −1 −10 −5 A 15.0 L A densities B 7.50 L B molar masses C 30.0 L C heats of formation D 5.0 L D heats of solution E 45.0 L E molecular polarities A B −1 0.1 mol L 0.1 mol L −1 −1 C 0.1 mol L D 0.1 mol L E −1 −1 0.1 mol L 37 Which of the following compounds is ionic? A H2O NaNO3(aq) B BaF2 NH4Br(aq) C PF3 KHSO4(aq) D SiC NaHCO3(aq) E SiF4 Na2CO3(aq) 34 When 0.483 grams of a compound is vapourized, its o volume is 0.358 L at 180 C and 84.7 kPa. What is the molar mass of the compound? 38 Which of the following has no lone pairs on the underlined atom? A OF2 B H2S C NH4 −1 D H3O −1 E HOF −1 A 23.8 g mol B 731 g mol C 14.3 g mol D 40.0 g mol E 60.0 g mol −1 mol L 36 What is the minimum volume of O2 needed to burn completely 15.0 L CH4 at standard temperature and pressure? 32 In the phrase “like dissolves like”, to what does the word “like” refer? 33 Which of the following salt solutions will have a pH o nearest to 7 at 25 C? −1 mol L −1 −1 6 / AVOGADRO EXAM © 2013 UNIVERSITY OF WATERLOO + + 徐老湿留学 39 A mixture of Fe2O3 and CuO weighing 1.000 g is reduced in a stream of hot hydrogen gas. The resulting mixture of metallic iron and metallic copper weighs 0.721 g. What was the percentage by mass of Fe2O3 in the original mixture? A 21.7% B 48.1% C 69.3% D 72.1% E 78.3% Molar masses (in g mol−1): O, 16.0 Fe, 55.85 Cu, 63.55 Fe2O3, 159.7 CuO, 79.55 40 For the reaction A → products, the concentration of A decreases by a factor of two every 32 minutes. If −1 the initial concentration of A is 1.0 mol L , what is the concentration of A after 48 minutes? −1 A 0.33 mol L B 0.35 mol L C 0.38 mol L D 0.44 mol L E 0.25 mol L −1 −1 −1 © 2013 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 7 徐老湿留学 DATA SHEET AVOGADRO EXAM DETACH CAREFULLY 1 1A 1 H 1.008 3 Li 6.941 11 Na 22.99 19 K 39.10 37 Rb 85.47 55 Cs 132.9 87 Fr (223) 2 2A 4 Be 9.012 12 Mg 24.31 20 Ca 40.08 38 Sr 87.62 56 Ba 137.3 88 Ra 226 3 4 3B 4B 21 22 Sc Ti 44.96 47.88 39 40 Y Zr 88.91 91.22 57-71 72 La-Lu Hf 178.5 89-103 104 Ac-Lr Rf 57 La 138.9 89 Ac (227) 58 Ce 140.1 90 Th 232.0 5 5B 23 V 50.94 41 Nb 92.91 73 Ta 180.9 105 Db 59 Pr 140.9 91 Pa 231.0 6 6B 24 Cr 52.00 42 Mo 95.94 74 W 183.9 106 Sg 60 Nd 144.2 92 U 238.0 7 7B 25 Mn 54.94 43 Tc (98) 75 Re 186.2 107 Bh 61 Pm (145) 93 Np 237.0 8 ← 26 Fe 55.85 44 Ru 101.1 76 Os 190.2 108 Hs 9 8B 27 Co 58.93 45 Rh 102.9 77 Ir 192.2 109 Mt 10 → 28 Ni 58.69 46 Pd 106.4 78 Pt 195.1 110 Ds 62 63 64 Sm Eu Gd 150.4 152.00 157.3 94 95 96 Pu Am Cm (244) (243) (247) Constants: mol−1 6.022 × 10 R = 0.082058 atm L K−1 mol−1 = 8.3145 kPa L K−1 mol−1 = 8.3145 J K−1 mol−1 23 −14 Kw = 1.0×10 F 96 485 C mol Equations: 65 Tb 158.9 97 Bk (247) 12 2B 30 Zn 65.38 48 Cd 112.4 80 Hg 200.6 112 Cn 66 Dy 162.5 98 Cf (251) 67 Ho 164.9 99 Es (252) 14 4A 6 C 12.01 14 Si 28.09 32 Ge 72.59 50 Sn 118.7 82 Pb 207.2 68 Er 167.3 100 Fm (257) 15 5A 7 N 14.01 15 P 30.97 33 As 74.92 51 Sb 121.8 83 Bi 209.0 69 Tm 168.9 101 Md (258) 16 6A 8 O 16.00 16 S 32.07 34 Se 78.96 52 Te 127.6 84 Po (209) 70 Yb 173.0 102 No (259) 17 7A 9 F 19.00 17 Cl 35.45 35 Br 79.90 53 I 126.9 85 At (210) 71 Lu 175.0 103 Lr (260) Conversion factors: NA = = 11 1B 29 Cu 63.55 47 Ag 107.9 79 Au 197.0 111 Sg 13 3A 5 B 10.81 13 Al 26.98 31 Ga 69.72 49 In 114.8 81 Tl 204.4 1 atm = 101.325 kPa = 760 Torr = 760 mm Hg o 0 C = 273.15 K (at 298 K) −1 PV = nRT k t1/2 = 0.693 pH = pKa + log ( [base] / [acid] ) 8 / AVOGADRO EXAM © 2013 UNIVERSITY OF WATERLOO x= −b ± b 2 − 4ac 2a 18 8A 2 He 4.003 10 Ne 20.18 18 Ar 39.95 36 Kr 83.80 54 Xe 131.3 86 Rn (222) 徐老湿留学 AVOGADRO EXAM 2014 UNIVERSITY OF WATERLOO DEPARTMENT OF CHEMISTRY 15 MAY 2014 TIME: 75 MINUTES This exam is being written by several thousand students. Please be sure that you follow the instructions below. We'll send your teacher a report on your performance. Top performers are eligible for a prize. The names of the top 200 students will be published in the September issue of Chem 13 News. 1. Print your name here: 2. Select, and enter on the STUDENT RESPONSE sheet, one of the following CODE numbers: 3. Print your name (last name, first name and optional middle initial) on the STUDENT RESPONSE sheet. Code 1 Ontario, now studying Grade 11 Chemistry in a nonsemestered school 4. Carefully detach the last page. It is the datasheet. Code 2 Ontario, now studying Grade 11 Chemistry in a semestered school Code 3 Ontario, Grade 11 Chemistry already completed Code 4 Any other Ontario student Code 5 Manitoba or Saskatchewan high school student Code 6 Québec high school student Code 7 Code 8 not used Alberta or British Columbia high school student Code 9 New Brunswick, Newfoundland, Nova Scotia, or Prince Edward Island high school student Code 10 Northwest Territories, Nunavut, or Yukon high school student 5. Now answer the exam questions. Questions are not in order of difficulty. Indicate your choice on the STUDENT RESPONSE sheet by marking one letter beside the question number. • Mark only one answer for each question. • Questions are all of the same value. • There is a penalty (1/4 off) for each incorrect answer, but no penalty if you do not answer. 6. Take care that you make firm, black pencil marks. Code 11 High school student outside Canada Code 12 Teacher Carefully detach the last page. It is the Data Sheet. 徐老湿留学 1 What is the SI unit for amount of substance? 2 5 Which of the following has the largest covalent radius? A gram A carbon, C B kilogram B fluorine, F C mole C silicon, Si D millilitre D sulfur, S E litre E chlorine, Cl −1 o Mercury has a density of 13.6 g mL at 0 C and 101 kPa. For this condition of temperature and pressure, what is the volume of 50.0 grams of mercury? 6 Which of the following statements concerning HCl is not correct? B The oxidation state of chlorine is −1. 3.68 mL B 6.80×10 mL C It is a stronger acid than HF. C 0.272 mL D The bond between hydrogen and chlorine is primarily ionic. D 63.6 mL E It is a gas at 25 C and 101 kPa. 2 36.4 mL o How many protons, neutrons and electrons are 3 − there in a single H ion? Treatment of C12H22O11 (table sugar) with excess concentrated H2SO4 yields a black residue (pure carbon) and water vapour. What is the maximum mass of carbon that can be obtained from exactly one gram of C12H22O11? A one neutron, one proton, one electron A 0.035 g B two neutrons, one proton, two electrons B 0.083 g C one neutron, three protons, two electrons C 0.12 g D three neutrons, one proton, one electron D 0.27 g E three neutrons, one proton, two electrons E 0.42 g 7 4 It is a strong acid in water. A E 3 A Which of the following exists as an atomic gas at o 25 C and 101 kPa? 8 There are only two naturally-occurring isotopes of gallium. gallium-69: 68.925581 u gallium-71 70.924705 u A hydrogen If the weighted atomic mass of gallium is 69.723 u, then what is the percent abundance of gallium-71? B chlorine A 33.8% C bromine B 39.9% D sulfur C 50.7% E krypton D 60.1% E 66.2% 2 / AVOGADRO EXAM © 2014 UNIVERSITY OF WATERLOO 徐老湿留学 9 Which pair of compounds are most similar in their physical and chemical properties? A HCl and HBr B H2O and H2S C 13 Both HClO4 and HCl are strong acids. Which of the following provides evidence that HClO4 is a stronger acid than HCl? A When dissolved in water, both HClO4 and HCl ionize completely. CO2 and SiO2 B The boiling point of HClO4 is higher than that of HCl. D CH3OH and B(OH)3 C E HCl and NaOH Commercial preparations of concentrated HClO4 are typically 70% HClO4 by mass whereas commercial preparations of HCl are about 38% HCl by mass. D When dissolved in acetic acid (CH3COOH), HClO4 ionizes to a greater extent than does HCl. E Copper metal dissolves readily in a concentrated solution of HClO4 but not in concentrated HCl solution. 10 When the Kelvin temperature of a fixed amount of an ideal gas is doubled and the pressure is doubled, what is the combined effect on the volume of the gas? A The volume remains constant. B The volume increases by a factor of two. C The volume increases by a factor of four. D The volume decreases by a factor of two. A EH E The volume decreases by a factor of four. B EH2 C E2H D EH3 E EH4 14 What is the general formula of the hydrides formed by the elements (E) of group 15? 11 What is the correct electron arrangement for a nickel (Ni) atom? (The first number in each list refers to the number of electrons in the first shell; the second number refers to the number of electrons in the second shell; and so on.) A 2, 6, 10, 10 B 10, 10, 8 C 2, 8, 2, 8, 2, 6 D 2, 8, 16, 2 E 2, 8, 8, 8, 2 15 Which second-period atom has the greatest number of unpaired electrons in its lowest energy state? 12 Which set of coefficients properly balances the equation below? Zn(s) + Ag (aq) → Zn (aq) + Ag(s) + A nitrogen, N B oxygen, O C fluorine, F D carbon, C E boron, B 2+ 16 Which of the following equations is not correct? A 1, 1, 1, 1 A Br2 + energy → 2 Br B 2, 1, 2, 1 B IF + energy → l + F C 1, 2, 1, 2 C F + e → F + energy D all of the above D CO2(g) → CO2(s) + energy E none of the above E O2 + energy → O + O + − − − − − © 2014 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 3 徐老湿留学 17 Which combination of elements will most likely form an ionic compound? A hydrogen and fluorine B sodium and magnesium C magnesium and oxygen D oxygen and chlorine E silicon and oxygen 18 A solid sample of impure carbon is 84% C by mass. How many carbon atoms are there in a 71.0 g sample? 21 What volume does 11.0 kg of carbon dioxide occupy o at 0 C and 101.3 kPa? 2.5×10 B 2.1×10 24 C 3.0×10 24 D 3.0×10 25 E 2.5×10 A hydrogen peroxide, H2O2 B oxygen, O2 C dinitrogen tetroxide, N2O4 D E B 5.60×10 L C 11.0 L D 577 L E 247 L 3 8 KI + 9 H2SO4 → 4 I2 + 8 KHSO4 + H2S + 4 H2O 25 19 What gas is produced when ammonium nitrate, NH4NO3, is added to NaOH(aq) and the solution gently heated? 2.47×10 L 22 In the reaction below, which element is reduced? 24 A 3 A A potassium (K) B iodine (I) C hydrogen (H) D sulfur (S) E oxygen (O) −1 23 When 25 mL of 0.10 mol L HBr(aq) is mixed with −1 25 mL of 0.20 mol L KOH(aq), what is the pH of o the final solution at 25 C? A 1.00 B 1.30 ammonia, NH3 C 7.00 nitric oxide, NO D 12.70 E 13.00 20 What is the maximum amount of HNO3 that can be obtained from 4.50 moles of NO2 and 3.00 moles of H2O according to the following equation? 24 What is the formula of copper(II) nitride? A Cu3N2 B Cu2N C Cu(NO3)2 D Cu2NO3 E Cu2N3 3 NO2 + H2O → 2 HNO3 + NO A 3.00 moles B 6.00 moles C 7.50 moles D 6.75 moles E 5.00 moles 4 / AVOGADRO EXAM © 2014 UNIVERSITY OF WATERLOO 徐老湿留学 25 What is the pressure of the gas in the apparatus below if the atmospheric pressure is 764 mmHg? Gas mercury (Hg) 28 In an experiment, a 1.52 gram sample of solid KClO3 is decomposed by heating to produce KCl and 310 mL o of O2 gas at 25.0 C and 103 kPa. What is the percent yield for this experiment? A 59% B 69% C 78% D 87% E 96% 48 mm 22 mm 29 Analysis of a solution of Co2(SO4)3 establishes that 2− −1 the concentration of SO4 is 0.060 mol L . What is 3+ the concentration of Co in this solution? A 26 mmHg B 70 mmHg C 738 mmHg A 0.010 mol L D 790 mmHg B 0.030 mol L E 834 mmHg C 0.040 mol L D 0.060 mol L E 0.090 mol L 26 Suppose the atomic mass scale had been set up with calcium (Ca) assigned a mass of 10 u. What would be the approximate atomic mass of oxygen? A 1.6 u B 4.0 u C 8.0 u D 64 u E 160 u 27 An unidentified metal X forms a compound with chlorine in which 1.036 g of X are present for every 0.3545 g of chlorine. The empirical formula of the compound is XCl2. What is the atomic symbol for X? A Hg B Mg C Ba D Rh E Pb −1 −1 −1 −1 −1 30 Which of the following is an isomer of diethyl ether, CH3CH2OCH2CH3? A butanal, CH3CH2CH2CHO B dimethyl ether, CH3OCH3 C t-butyl alcohol, (CH3)3COH D butanoic acid, CH3CH2CH2COOH E butan-2-one, CH3CH2COCH3 31 Which compound contains oxygen in the highest (most positive) oxidation state? A KO3 B K2O2 C F2O D K2O E NO2 © 2014 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 5 徐老湿留学 32 Which of the following statements is not correct? A B C D E Deviations from ideal gas behaviour are more significant at high pressures. 35 Which of the following is the Lewis structure (i.e., the − best electron dot structure) for the N3 ion? A N N N Attractive intermolecular forces cause a decrease in the observed pressure of a gas compared to what is predicted for an ideal gas. B N N N Deviations from ideal gas behaviour are more significant at very low temperatures. C N N N At very high pressures, the observed molar volume of a gas is smaller than what is predicted for an ideal gas. D N N N N For low to moderate pressures, attractive intermolecular forces are the primary cause of deviations from ideal gas behaviour. + 33 A solution has [H ] = 3.7×10 the pH of this solution ? −3 −1 mol L . What is E N 36 A gaseous compound contains hydrogen, carbon and nitrogen. If combustion of 1.0 L of the compound in oxygen yields 2.0 L CO2, 3.5 L of H2O and 0.50 L of N2, all measured at the same temperature and pressure, what is the empirical formula of the compound? A 2.43 B 3.57 A CHN C 3.70 B CH2N2 D 4.04 C C4H7N E 5.60 D CH4N7 E C2H7N 34 A container of helium gas, initially at 217 kPa and o o 5.00 C, is heated to 80.0 C. The container is opened briefly to allow some gas to escape and then it is closed. If the final pressure is 93.0 kPa, what fraction of the helium gas remains in the container? A 0.15 B 0.34 C 0.42 D 0.58 E 0.79 N 37 In a well-insulated container, an endothermic reaction takes place. When the reaction is done, the temperature of the contents will be 6 / AVOGADRO EXAM © 2014 UNIVERSITY OF WATERLOO A higher than before the reaction began B higher or lower than at the start of the reaction depending on the masses of reactants used C independent of the heat capacities of the substances involved D the same as before the reaction began E be lower than before the reaction began 徐老湿留学 38 Which of the following is less soluble in hot water than in cold water? A glucose, C6H12O6 B methane, CH4 C silver chloride, AgCl D silver nitrate, AgNO3 E sodium hydroxide, NaOH 39 At high temperatures, hydrogen iodide (HI) reacts reversibly according to the following equation. 2 HI(g) H2(g) + I2(g) In an experiment, an initial reaction mixture containing 0.100 mol each of HI, H2 and I2 at room temperature is prepared and then heated to a high temperature. After some time has passed, the amount of HI in the system is found to be.0.120 moles. What is the amount of H2 in the system at that time? A 0.120 moles B 0.110 moles C 0.090 moles D 0.080 moles E 0.060 moles −1 40 A 6.00 mol L aqueous solution of CsCl is 58.0% CsCl by mass. What is the density of this solution? Molar masses (in g/mol) A 0.586 g/mL H2O, 18.02 CsCl, 168.35 B 0.842 g/mL C 1.01 g/mL D 1.74 g/mL E 16.3 g/mL © 2014 UNIVERSITY OF WATERLOO AVOGADRO EXAM / 7 徐老湿留学 DATA SHEET AVOGADRO EXAM DETACH CAREFULLY 1 1A 1 H 1.008 3 Li 6.941 11 Na 22.99 19 K 39.10 37 Rb 85.47 55 Cs 132.9 87 Fr (223) 2 2A 4 Be 9.012 12 Mg 24.31 20 Ca 40.08 38 Sr 87.62 56 Ba 137.3 88 Ra 226 3 4 3B 4B 21 22 Sc Ti 44.96 47.88 39 40 Y Zr 88.91 91.22 57-71 72 La-Lu Hf 178.5 89-103 104 Ac-Lr Rf 57 La 138.9 89 Ac (227) 58 Ce 140.1 90 Th 232.0 5 5B 23 V 50.94 41 Nb 92.91 73 Ta 180.9 105 Db 59 Pr 140.9 91 Pa 231.0 6 6B 24 Cr 52.00 42 Mo 95.94 74 W 183.9 106 Sg 60 Nd 144.2 92 U 238.0 7 7B 25 Mn 54.94 43 Tc (98) 75 Re 186.2 107 Bh 61 Pm (145) 93 Np 237.0 8 ← 26 Fe 55.85 44 Ru 101.1 76 Os 190.2 108 Hs 9 8B 27 Co 58.93 45 Rh 102.9 77 Ir 192.2 109 Mt 10 → 28 Ni 58.69 46 Pd 106.4 78 Pt 195.1 110 Ds 62 63 64 Sm Eu Gd 150.4 152.00 157.3 94 95 96 Pu Am Cm (244) (243) (247) Constants: mol−1 6.022 × 10 R = 0.082058 atm L K−1 mol−1 = 8.3145 kPa L K−1 mol−1 = 8.3145 J K−1 mol−1 23 −14 Kw = 1.0×10 F 96 485 C mol Equations: 65 Tb 158.9 97 Bk (247) 12 2B 30 Zn 65.38 48 Cd 112.4 80 Hg 200.6 112 Cn 66 Dy 162.5 98 Cf (251) 67 Ho 164.9 99 Es (252) 14 4A 6 C 12.01 14 Si 28.09 32 Ge 72.59 50 Sn 118.7 82 Pb 207.2 68 Er 167.3 100 Fm (257) 15 5A 7 N 14.01 15 P 30.97 33 As 74.92 51 Sb 121.8 83 Bi 209.0 69 Tm 168.9 101 Md (258) 16 6A 8 O 16.00 16 S 32.07 34 Se 78.96 52 Te 127.6 84 Po (209) 70 Yb 173.0 102 No (259) 17 7A 9 F 19.00 17 Cl 35.45 35 Br 79.90 53 I 126.9 85 At (210) 71 Lu 175.0 103 Lr (260) Conversion factors: NA = = 11 1B 29 Cu 63.55 47 Ag 107.9 79 Au 197.0 111 Sg 13 3A 5 B 10.81 13 Al 26.98 31 Ga 69.72 49 In 114.8 81 Tl 204.4 1 atm = 101.325 kPa = 760 Torr = 760 mm Hg o 0 C = 273.15 K (at 298 K) −1 PV = nRT k t1/2 = 0.693 pH = pKa + log ( [base] / [acid] ) 8 / AVOGADRO EXAM © 2014 UNIVERSITY OF WATERLOO 18 8A 2 He 4.003 10 Ne 20.18 18 Ar 39.95 36 Kr 83.80 54 Xe 131.3 86 Rn (222)