Final Practice Questions Chem102 Set#1 PDF

Practice Questions for Final Exam Chem102 Equations and Constants Avagadro’s number, NA= 6.022x1023 density = mass/volume 1 J = 1 kg m2/sec2 c=2.998x108 m/s...

Practice Questions for Final Exam Chem102 Equations and Constants Avagadro’s number, NA= 6.022x1023 density = mass/volume 1 J = 1 kg m2/sec2 c=2.998x108 m/s actual % yield = × 100 theoretica l h=6.626x10 – 34J s M = Molarity = mol solute/L solution E=h c= λ = h/mv qrxn = – qsolution q = c m ∆T q = C ∆T 1 1 𝐸 = −2.178x10−18 ( − ) cH2O = 4.184 J/goC 𝑛2𝑓𝑖𝑛𝑎𝑙 𝑛2 𝑖𝑛𝑖𝑡𝑖𝑎𝑙 RH = 2.178 × 10–18 J 101.3 J = 1 L atm En = RH (1/n2) ∆U = ∆E K = °C + 273 PV=nRT ∆U = q + w w = – Pext∆V 𝐿 𝑎𝑡𝑚 𝐽 R= 0.08206 = 8.314 𝑚𝑜𝑙𝑒 𝐾 𝑚𝑜𝑙𝑒 𝐾 H = U + PV (at constant P) H=qp STP = 1 atm, 0 oC U=qv (at constant V) Ptotal = P1 + P2 + P3 +... Ho =  np Hfo (products) –  nr Hfo (reactants) 𝑛1 𝑃1  =𝑛 = 𝑃𝑡𝑜𝑡𝑎𝑙 𝑡𝑜𝑡𝑎𝑙 Hrxn =  n x Dbonds broken –  n x D bonds formed density = mass/volume = BE(reactant) – BE(product) PM=dRT (M=molar mass, d=density) 1 J = 1 kg m2/sec2 −𝑏±√𝑏2 −4𝑎𝑐 3𝑅𝑇 Kp = Kc(RT)Δn 𝑥= 2𝑎 √ 𝑟𝑎𝑡𝑒 1 𝑀1 √𝑀2 = = 𝑟𝑎𝑡𝑒 2 3𝑅𝑇 √𝑀1 √ 𝑀2 𝑡𝑖𝑚𝑒 1 √𝑀1 = 𝑡𝑖𝑚𝑒 2 √𝑀2 1 atm = 760 torr = 760 mm Hg kinetic energy = (1/2) mv2 KEAVE = (3/2) RT P1V1 PV = 2 2 n1T1 n 2 T2 𝑛 (𝑃𝑜𝑏𝑠 + 𝑎(𝑉)2 )(V  nb) = nRT van der Waal’s Eq Final Practice Set#1-1 Pauling’s Table of Electronegativity Values Solubility Rules: 1. Most nitrate, acetate, chlorate & bicarbonate salts are soluble. 2. Most salts of alkali metals and ammonium cations are soluble. 3. Most chloride, bromide and iodide salts are soluble. Exceptions: salts containing Ag+, Pb2+ and Hg22+ ions are insoluble 4. Most sulfate salts are soluble. Exceptions: sulfates containing Ca2+, Sr2+, Ba2+, Pb2+, Hg22+ and Ag+ ions are insoluble 5. Most hydroxide salts are insoluble. Exceptions: hydroxides containing alkali metals, ammonium ions, Ba2+, Sr2+ and Ca2+ ions are soluble 6. Most sulfide, carbonate, chromate and phosphate salts are insoluble. Exceptions: salts of alkali metals and ammonium cations are soluble Final Practice Set#1-2  PERIODIC TABLE OF THE ELEMENTS 1 18 1A 8A 1 2 H 2 13 14 15 16 17 He 1.008 2A 3A 4A 5A 6A 7A 4.003 3 4 5 6 7 8 9 10 Li Be B C N O F Ne 6.941 9.012 10.81 12.01 14.01 16.00 19.00 20.18 11 12 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar 22.99 24.31 3 4 5 6 7 8 9 10 11 12 26.98 28.09 30.97 32.07 35.45 39.95 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.93 58.69 63.55 65.38 69.72 72.59 74.92 78.96 79.90 83.80 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.47 87.62 88.91 91.22 92.91 95.94 98 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 Cs Ba La* Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 209 210 222 87 88 89 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 Fr Ra Ac† Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og (223) 226 (227) (261) (262) (263) (264) (265) (268) (271) (272) (285) 58 59 60 61 62 63 64 65 66 67 68 69 70 71 * Lanthanides Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 140.1 140.9 144.2 145 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0 90 91 92 93 94 95 96 97 98 99 100 101 102 103 † Actinides Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232.0 231 238 244 242 243 247 247 251 252 257 258 259 260 Final Practice Set#1-3 1. An unknown ion forms a compound with perchlorate having the molecular formula XClO4. The unknown ion has 36 electrons. What is the identity of the unknown element X? a) Kr b) K c) Sr d) Ca e) Rb 2. Which of the following have both names and corresponding formulas correct? I. P2O5 phosphorus pentoxide II. NiClO2 nickel(II) hypochlorite III. RbNO2 rubidium nitrate IV. ZnO2 zinc oxide a) I and II b) I and III c) II and IV d) I, III, and IV e) none of the above 3. Which of the following is true about the state of an individual atom? a) An individual atom should be considered to be a solid. b) An individual atom should be considered to be a liquid. c) An individual atom should be considered to be a gas. d) The state of the atom depends on which element it is. e) An individual atom cannot be considered to be solid liquid, or gas. 4. α particles are a product of radioactive decay that contain two protons and two neutrons. These α particles travel at 5.00% the speed of light (2.998x108m/s). What is the speed of an α particle in km/hr? a) 5.40 km/hr b) 5.396x109 km/hr c) 5.40x109 km/hr d) 5.40x107 km/hr e) 5.39x107 km/hr 5. Given the values of H and S, which of the following changes will be non-spontaneous at constant T and P? a) H = +25 kJ, S = +5.0 J/K, T = 300. K b) H = +25 kJ, S = +100.0 J/K, T = 300. K c) H = - 10. kJ, S = +5.0 J/K, T = 298 K d) H = - 10. kJ, S = - 40. J/K, T = 200. K 6. A beam of light hits a hydrogen atom, exciting the electron from ground state to the n = 5 energy level. What is the frequency of the beam of light? a) 2.09x10–18 s-1 b) -2.09x10–18 s-1 c) 3.15x1015 s-1 d) -0.0137 s-1 e) 0.263 s-1 Final Practice Set#1-4  DNA molecules are complex organic compounds which contain vital information and are the control centers for the cell. Parts of DNA molecules contain the following organic compound, guanine, which has the following skeletal structure: Complete the Lewis structure for guanine and answer the following TWO questions: 7. How many double bonds are in the completed structure? a. 1 b. 2 c. 3 d. 4 e. 5 8. How many pairs of lone electrons are in the completed structure? a. 5 b. 6 c. 7 d. 8 e. 9 9. What is the density (in g/L) of a gas with a molar mass of 60 g/mol at 0.75 atm and 27 °C? a) 0.547 g/L b) 1.09 g/L c) 1.83 g/L d) 2.13 g e) 1.95 g/L 10. Consider an element E. If 2.00 g of E reacts exactly with 10.1 g of chlorine gas to form a compound with the formula ECl4, what is the identity of E? a) Cl b) Si c) P d) Al e) Ge 11. An aerosol can contains 400.0 ml of compressed gas at 5.2 atm pressure. When the gas is sprayed into a large plastic bag, the bag inflates to a volume of 2.14 L. What is the pressure of gas inside the plastic bag? a) 1.06 atm b) 0.97 atm c) 2.50 atm d) 1.00 atm e) 6.2 atm 12. A sample of gas is at pressure=1atm, volume= 1L, and T= 298K. What would happen to the pressure if the volume were reduced to 0.4 L and the temperature increased to 533K? a) Pressure will increase, because pressure is indirectly related to volume and directly related to temperature. b) Pressure will decrease, because pressure is directly related to volume and indirectly related to temperature. c) Pressure will decrease, because pressure is indirectly related to volume and directly related to temperature. d) Pressure will increase, because pressure is directly related to volume and temperature Final Practice Set#1-5 13. Consider the following ionization energies for Al: Al (g) Al+ (g) + e- I1 = 580 kJ/mol Al + (g) Al2+ (g) + e- I2 = 1815 kJ/mol Al 2+(g) Al3+ (g) + e- I3 = 2740 kJ/mol Al 3+(g) Al4+ (g) + e- I4 = 11,600 kJ/mol Which one of the four ions has the greatest electron affinity? a) Al+ b) Al2+ c) Al3+ d) Al4+ 14. Air is concealed in a tank of a specified volume. The air in the tank is initially at 20˚C and 1.0 atm. It is then heated to 250˚C and 1.0 atm. What will happen to the density of the air in the container? a) Density will decrease b) Density will stay the same c) Density will increase d) Not enough information is given 15. Carbon tetrachloride, CCl4, an organic solvent, is prepared by the reaction of Cl2 (g) with CS2. Determine the ∆H for this reaction: CS2 (l) + 3Cl2 (g) CCl4 (l) + S2Cl2 (l) Given the following data: CS2(l) + 3 O2(g) CO2(g) + 2 SO2(g) ∆Ho = – 1077 kJ 2S(s) + Cl2(g) S2Cl2(l) ∆Ho = – 60.2 kJ C(gr) + 2 Cl2(g) CCl4(l) ∆Ho = – 135.4 kJ S(s) + O2(g) SO2(g) ∆Ho = – 296.9 kJ C(gr) + O2(g) CO2(g) ∆Ho = – 393.5 kJ a) – 558.4 kJ b) – 164.9 kJ c) – 1352.5 kJ d) – 461.8 kJ e) – 285.3 16. An unknown metal salt, MBr2, dissolves in water. Reacting this salt with Na2SO4 forms a white precipitate. Of the following choices, which is most likely to be the unknown metal? a) Ni2+ b) Ba2+ c) Cr3+ d) K+ 17. Consider the following balanced equation: C7H16 (l) + 11 O2 (g)  7 CO2 (g) + 8 H2O (l) If 25 g of C7H16 (l) is combusted, how much H2O will be formed (in g)? a) 18 g b) 36 g c) 46 g d) 63 g Final Practice Set#1-6 18. Four different flasks contain gas samples at 298 K. In which of the following samples will the gas molecules be moving the fastest? a) N2 b) CO2 c) O2 d) H2 19. For which of the following reactions will Kp = K? I. 2NH3(g) + CO2 (g)  N2CH4O (s) + H2O (g) II. 2KClO3(s)  2KCl(s) + 3O2(g) III. CuO(s) + H2(g)  Cu(l) + H2O (g) IV. N2(g) + 3H2(g)  2NH3 (g) a) I, II, III, and IV b) I and IV c) III and IV d) III only e) II and IV 20. A sample of methane gas was collected over water at 35°C. The sample was found to have a total pressure of 756 mm Hg. Determine the partial pressure of the methane gas in the sample (vapor pressure of water at 35°C is 41 mm Hg). a) 760 mm Hg b) 41 mm Hg c) 715 mm Hg d) 797 mm Hg e) 756 mm Hg 21. If a sample of CH4 effuses at a rate of 9.0 mol per hour at 35°C, which of the gases below will effuse at approximately twice the rate under the same conditions? a) CO b) He c) O2 d) F2 e) SiH4 22. The standard enthalpy of combustion of ethane gas, C2H4(g), is -1411.1 kJ/mol at 298 K. Given the following enthalpies of formation, calculate Hof for C2H4(g). CO2(g): – 393.5 kJ/mol H2O(l): – 285.8 kJ/mol a) 52.5 kJ/mol d) – 63.2 kJ/mol b) – 52.5 kJ/mol e) – 586 kJ/mol c) – 1358.6 kJ/mol 23. A compound was found to contain 55.2% Xenon and 44.8% chlorine. What is the empirical formula? a) XeCl2 b) XeCl3 c) XeCl4 d) Xe2Cl2 e) Xe2Cl3 Final Practice Set#1-7 24. Consider the following reactions: SiH4 (g) + O2 (g)  SiO2 (g) + H2O (g) ∆H = 37.8 kJ How many of the following will increase the amount of water present in solution? I. Volume Decreases II. Temperature Decreases III. Amount of SiO2 increases IV. Amount of SiH4 increases V. O2 (g) is added VI. The sample is placed in a refrigerator. a) 1 b) 2 c) 3 d) 4 e) 5 25. Consider the following reaction in a 5L chamber ran at 25oC and 1atm 2 SO2 (g) + O2 (g)  2 SO 3(g) K = 1.2 E-4 ∆H = – 64KJ Which of the following statements are true? I. Increasing the volume of the container will cause equilibrium to shift to the left II. Increasing temperature will cause equilibrium to shift to the left III. Increasing the pressure will cause equilibrium to shift to the left IV. Increasing the amount of sulfur trioxide in the container will cause equilibrium to shift to the left a) I and II b) I and III c) I, III, and IV d) I, II, III e) I, II, IV 26. At a particular temperature, 12.0 mol SO3 is placed into a 3.0 L rigid container, and the SO3 dissociates by the reaction 2SO3 (g)  2SO2 (g) + O2 (g) At equilibrium, 3.0 mol SO2 is present. Calculate K for this reaction. a) 0.90 b) 0.11 c) 0.33 d) 0.056 e) 1.0 27. For the reaction A + B  C, the initial concentrations of the reactants and products are shown below. How many of the cases below will not shift under the conditions as stated? (K = 96., and assume In all cases, the temperature is constant) Case 1: [A]0 = 0.222 M, [B]0 = 0.222 M, [C]0 = 4.74 M Case 2: [A]0 = 0.0233 M, [B]0 = 0.0123 M, [C]0 = 0.999 M Case 3: [A]0 = 0.0333 M, [B]0 = 0.0333 M, [C]0 = 0.1067 M Case 4: [A]0 = 8 M, [B]0 = 8 M, [C]0 = 5926 M a) 1 b) 2 c) 3 d) All of the above. e) None of the above. Final Practice Set#1-8 28. In which of the following groups of substances would dispersion forces be the only significant factors in determining boiling points? I. Cl2 II. HF III. Ne IV. KNO2 V. CCl4 a) II and V b) III, IV, and V c) II and IV d) I, III and V e) I, II, and III 29. Difluoromethane, CF2H2, has been considered as a replacement for the chlorofluorocarbon frenon, CF2Cl2. The boiling point of CF2H2 is -56C and the boiling point of CF2Cl2 is -29C. Which of the following statements concerning these two compounds is false? (Carbon is the central atom in both molecules.) a) CF2H2 exhibits hydrogen bonding intermolecular forces. b) Both compounds are gases at room temperature. c) CF2Cl2 exhibits stronger London dispersion forces as compared to CF2H2. d) Overall, CF2Cl2 exhibits stronger intermolecular forces as compared to CF2H2. 30. Which of the following orbitals can hold the most electrons? a) 1s b) 1p c) 1d d) 2d e) 3f 31. In theory, how many different elements in the ground state can have exactly 12 electrons in various ‘s’ orbitals, have exactly 30 electrons in various ‘d’ orbitals, and have two or more unpaired electrons? a) 0 b) 1 c) 2 d)3 e) 5 32. At equilibrium, the concentrations of the products and reactants for the reaction, H2 (g) + I2 (g)  2 HI (g), are [H2] = 0.106 M; [I2] = 0.022 M; [HI] = 1.29 M Calculate the new equilibrium concentration of HI (in M) if the equilibrium concentrations of H2 and I2 are 0.95 M and 0.019 M respectively. a) 92.9 b) 1.79 c) 713 d) 1.2x104 e) 3.59 33. Given the following molecules: SiF4, SeF4, XeF4 Which molecule(s) has/have tetrahedral shape and which molecule(s) is/are polar? a) SeF4 has tetrahedral shape and XeF4 is polar b) SiF4 has tetrahedral shape and SeF4 is polar c) XeF4 has tetrahedral shape and SiF4 is polar d) All of these molecules have tetrahedral shape and all of these molecules are polar e) All of these molecules have tetrahedral shape and all of these molecules are nonpolar Final Practice Set#1-9 34. What do the following molecules all have in common? KrF2, ICl3, SF4, AsCl5 a) All have 90o bond angles. b) All have central atoms that are dsp3 hybridized c) All are polar d) All have octahedral shape e) All have 109o bond angles Consider the following unbalanced reaction for the next TWO questions: N2O5 + H2O HNO3 35. After the equation is balanced, what is the coefficient of HNO3? a) 2 b) 3 c) 1 d) 4 36. If 0.4520 g of N2O5 reacts with excess water, how much HNO3 will be formed? a) 0.3454 g b) 0.2637 g c) 0.5273 g d) 0.1318 g 37. Consider the following reactions (Use the solubility rules given in Zumdahl) : I. 3 MgSO4 + 2Na3PO4 II AgNO3 + NaCl III. Ba(NO3)2 + K2CO3 For which reactions will a precipitate form? a) I, III b) I, II c) All of the above reactions will form a precipitate d) None of the above reactions will form a precipitate. 38. How many atoms are in 0.7165 mol of Cr (s) ? a) 37.26 atoms b) 2.244 x 1025 atoms c) 3.316 x 1024 atoms d) 4.315 x 1023 atoms 39. Which of the following organic compounds has the lowest vapor pressure at – 50C? a.) CH4 b) CH3OCH3 c) CH2CH2 d)CH3CH2CH3 Final Practice Set#1-10 40. Consider the terms internal energy, heat, work, and enthalpy. How many of these are state functions? a) 0 (none) b) 1 c) 2 d) 3 e) 4 (all are state functions) 41. Arrange the following atoms in order of increasing size: O, S, As, Se a) O < S < As < Se b) O < S < Se < As c) O < Se < S < As d) O < As < S < Se 42. Consider the following cyclic process carried out in two steps on a gas: Step 1: 45J of heat are added to the gas and 10 J of expansion work are performed Step 2: 60 J of heat are removed from the gas as the gas is compressed back to the initial state Which of the following statements (a-c) is/are true concerning this process? a) For step 1, the surroundings does work on the system b) For step 2, ΔE2= – 55 J c) For step 2, w2= 5 J d) All of these statements (a-c) are true e) None of these statements (a-c) are true 43. The successive ionization energies for an unknown element are: I1 = 896 kJ/mol I2 = 1752 kJ/mol I3 = 14807 kJ/mol I4 = 17948 kJ/mol Which group in the periodic table does the unknown element most likely belong to? a) IA b) IIA c) IIIA d) IVA 44. If a system loses 250 kJ of heat at the same time that it is doing 500 kJ of work, what is the change in the internal energy of the system? a) +250 kJ b) – 250 kJ c) +750 kJ d) – 750 kJ Final Practice Set#1-11 45. A 25.0 g piece of aluminum (which has a molar heat capacity of 24.03 J/oC mol) is heated to 82.4 oC and dropped into a coffee cup calorimeter containing water initially at 22.3oC. The final temperature of the water and aluminum mixture is 24.9oC. Calculate the mass of water in the calorimeter. The specific heat of water is 4.18 J/oC. a) 120 g b) 6.6 g c) 3200 g d) 2100 g e) 250 g 46. Predict which bond will be the most polar: a) Al – Br b) Ga – Br c) In – Br d) Tl – Br 47. The heat of combustion for the conversion of 1 mole of carbon to carbon dioxide is -410 kJ. How many kJ of heat would be liberated from the complete combustion of 60.0 g of carbon? a) – 82 kJ b) – 559 kJ c) – 2050 kJ d) – 24,600 kJ 48. In one beaker you have 4.06g of BaSO4, and you combine it with 22.1g of BaSO4 from another container. Then you evenly distribute the compound into 10 different vials. Using correct significant figures, how much BaSO4 do you have in each vial, in grams? a) 2.616g b) 3g c) 6.27g d) 2.62g e) 2.6g 49. You want to make a solution that has a concentration of 10.0mM CaCl2. If you need 125.00mL of this solution, how much CaCl2 do you need to add (MM CaCl2 = 110.98g/mol)? a) 1.13x10-5g b) 0.139g d) 0.14g d) 1.1x10-5g e) 139g 50. Ernest Rutherford is credited with determining the structure of atoms by what experiment? a) The oil drop experiment b) The cathode-ray tube experiment c) The thin foil experiment d) The blackbody experiment e) The radioactive emission experiment Final Practice Set#1-12 51. Which of the following statements about the photoelectric effect is false? a) The energy of the light that hits a metal surface is equal to the energy of the emitted electrons it dislodges from the metal. b) The kinetic energy of electrons emitted from a metal surface increases linearly with the frequency of light used to knock off the electrons. c) Intensity of light hitting a metal surface is directly related to the number of electrons emitted. d) Below a certain intensity of light, no electrons will be dislodged from the surface the light hits. e) If the light does not have a high enough frequency, then when it hits the metal surface no electrons are dislodged. 52. The compound copper (II) acetoarsenite is also known as Paris Green, and is often used in fireworks for its emerald green color upon burning that has a wavelength of about 500.nm. If one mole of Paris Green is burned, how much energy is released in the form of photons? a) 239 J b) 3.98x10-19 J c) 3.98x1-28 J d) 2.39x10-4J e) 239 kJ 53. As a way to educate yourself about American living, you enjoy listening to the radio broadcasts of This American Life on NPR. In Urbana-Champaign, you can find this radio program on 90.9FM. This means the radio waves of the station have a frequency of 90.9MHz. What is the wavelength of a broadcast of This American Life? a) 3.30 m b) 3.03x10-13 m c) 3.30x106 m d) 3.03x10-7 m e) 303 m 54. Arrange the following ions or atoms in order of increasing size: Al3+, P3-, O2-, Cl- a) Al3+ < Cl- < O2- < P3- b) O2-< Al3+ < Cl- < P3- c) Al3+ < O2- < Cl- < P3- d) Al3+ < O2- < P3- < Cl- Final Practice Set#1-13