CHM2045: Fall 2000—Exam #3: Quantum Physics and Atomic Structure, Exams of Chemistry

Download CHM2045: Fall 2000—Exam #3: Quantum Physics and Atomic Structure and more Exams Chemistry in PDF only on Docsity! CHM2045: Fall 2000—Exam #3 Form A November 4, 2009 FORM A 0 Instructions: BEFORE YOU BEGIN, MARK YOUR NAME, USF ID NUMBER, SECTION NUMBER, AND FORM LETTER ON YOUR SCANTRON SHEET. FAILURE TO DO THIS WILL RESULT IN A PENALTY. For each problem determine the best answer and mark the appropriate place on your scantron sheet. The exam consists of 20 questions and you will be given 50 minutes. Abbreviations and Symbols Constants and Equations amount of substance n kelvin K NA = 6.022 x 10 23 mol -1 atmosphere atm kilo- (prefix) k R = 8.3145 J mol -1 K -1 atomic mass unit u liter L R = 0.08206 L-atm mol -1 K -1 Avogadro constant NA milli- (prefix) m Celsius temperature °C molar M E = h! c ="! centi- (prefix) c molar mass M h = 6.626 x 10 -34 J s enthalpy H mole mol c = 2.998 x 10 8 m s -1 frequency ! Planck’s constant h 1 L-atm = 101.325 J gas constant R second s gram g speed of light c hour h wavelength " joule J 1 1 H 1.008 Periodic Table 2 He 4.003 2 3 Li 6.941 4 Be 9.012 5 B 10.81 6 C 12.01 7 N 14.01 8 O 16.00 9 F 19.00 10 Ne 20.18 3 11 Na 22.99 12 Mg 24.31 13 Al 26.98 14 Si 28.09 15 P 30.97 16 S 32.07 17 Cl 35.45 18 Ar 39.95 4 19 K 39.10 20 Ca 40.08 21 Sc 44.96 22 Ti 47.88 23 V 50.94 24 Cr 52.00 25 Mn 54.94 26 Fe 55.85 27 Co 58.93 28 Ni 58.69 29 Cu 63.55 30 Zn 65.39 31 Ga 69.72 32 Ge 72.61 33 As 74.92 34 Se 78.96 35 Br 79.90 36 Kr 83.80 5 37 Rb 85.47 38 Sr 87.62 39 Y 88.91 40 Zr 91.22 41 Nb 92.91 42 Mo 95.94 43 Tc (98) 44 Ru 101.1 45 Rh 102.9 46 Pd 106.4 47 Ag 107.9 48 Cd 112.4 49 In 114.8 50 Sn 118.7 51 Sb 121.8 52 Te 127.6 53 I 126.9 54 Xe 131.3 6 55 Cs 132.9 56 Ba 137.3 57* La 138.9 72 Hf 178.5 73 Ta 180.9 74 W 183.9 75 Re 186.2 76 Os 190.2 77 Ir 192.2 78 Pt 195.1 79 Au 197.0 80 Hg 200.6 81 Tl 204.4 82 Pb 207.2 83 Bi 209.0 84 Po (209) 85 At (210) 86 Rn (222) 7 87 Fr (223) 88 Ra 226.0 89** Ac 227.0 104 Rf (261) 105 Db (262) 106 Sg (263) 107 Bh (262) 108 Hs (265) 109 Mt (266) 110 (269) 111 (272) 112 (277) ! *Lanthanides 58 Ce 140.1 59 Pr 140.9 60 Nd 144.2 61 Pm (145) 62 Sm 150.4 63 Eu 152.0 64 Gd 157.3 65 Tb 158.9 66 Dy 162.5 67 Ho 164.9 68 Er 167.3 69 Tm 168.9 70 Yb 173.0 71 Lu 175.0 **Actinides 90 Th 232.0 91 Pa 231.0 92 U 238.0 93 Np 237.0 94 Pu (244) 95 Am (243) 96 Cm (247) 97 Bk (247) 98 Cf (251) 99 Es (252) 100 Fm (257) 101 Md (258) 102 No (259) 103 Lr (260) ! CHM2045: Fall 2000—Exam #3 Form A November 4, 2009 FORM A 1 1. Consider the following sets of quantum numbers, n, l, ml, and ms, respectively. Which of these, if any, is not allowed for an electron in an atom? (A) n = 1 l = 0 ml = 0 ms = +1/2 (B) n = 8 l = 7 ml = -6 ms = -1/2 (C) n = 3 l = 3 ml = -2 ms = +1/2 (D) n = 2 l = 1 ml = -1 ms = -1/2 (E) All the above are allowed. 2. For a hydrogen atom, which pair of energies (listed according to their n values) would have the greatest difference in energy? (A) n = 3 and n = 4 (B) n = 5 and n = 10 (C) n = 3 and n = 100 (D) n = 1 and n = 2 (E) Cannot be determined. 3. The following species all have the same number of electrons (we call this “isoelectronic”). Which would be expected to have the largest atomic radius? (A) O2- (B) F - (C) Na+ (D) N3- (E) Mg2+ 4. Before Mendeleev, elements were listed in the order of their atomic weights (molar masses). When he set up the periodic table he deviated from this rule by listing Te (127.60 g/mol) before I (126.90 g/mol). What was the reason for this? (A) Iodine resembles F, Cl, and Br in its chemical properties; Te is much more like S and Se. (B) Ga and Ge had not yet been discovered; their absences misaligned the columns. (C) Mendeleev showed that the atomic weights of I and Te were incorrect. (D) Iodine is a solid whereas fluorine and chlorine are gases and bromine is a liquid. (E) Iodine is a metal whereas tellurium is a nonmetal. 5. The length of an H-H bond is 74 pm and that of an I-I bond is 266 pm. What is the most reasonable estimate for the length of an H-I bond? (A) 340 pm (B) 170 pm (C) 192 pm (D) 148 pm (E) 158 pm CHM2045: Fall 2000—Exam #3 Form A November 4, 2009 FORM A 4 17. Which reaction below represents the second electron affinity of S? (A) S(g) + e– " S–(g) (B) S–(g) + e– " S2–(g) (C) S(g) " S(g) + e– (D) S–(g) " S(g) + e– (E) S2–(g) " S–(g) + e– 18. How many photons are contained in a burst of yellow light (589 nm) from a sodium lamp that contains 609 kJ of energy? (A) 3.37 ! 1019 photons (B) 3.06 ! 1030 photons (C) 1.81 ! 1024 photons (D) 4.03 ! 1028 photons (E) 2.48 ! 1025 photons 19. Give the ground state electron configuration for Br–. (A) [Ar]4s23d104p5 (B) [Ar]4s24p6 (C) [Ar]4s24d104p6 (D) [Ar]4s23d104p4 (E) [Ar]4s23d104p6 20. Choose the orbital diagram that represents the ground state of N. (A) (B) (C) (D) (E) 21. Which energy gap in the Bohr Model would be associated with the longest wavelength? (A) from n = 2 to n = 1 (B) from n = 6 to n = 5 (C) from n = 10 to n = 9 (D) from n = 11 to n = 10 (E) They have the same wavelength. CHM2045: Fall 2000—Exam #3 Form A November 4, 2009 FORM A 5 22. Which of the following concepts/models/phenomena are related to “quantized energy levels”? (A) Fireworks (B) Neils Bohr’s model for the atom (C) the “line spectra” of helium emission (D) Both (b) and (c) (E) All of the above. 23. Which one does not have a completely full quantum level? (A) Na+ (B) O2 (C) O2– (D) He (E) The quantum levels are completely full in all of the above. 24. In the Born-Haber cycle for Mg(s) + Cl2(g) " MgCl2(s), which step(s) is (are) exothermic for the formation of crystalline solid? (The following may not be balanced equations, but describe reaction processes.) (1) Mg(g) + 2Cl (g) ! Mg2+(g) + 2Cl (g) (2) Mg2+(g) + 2Cl(g) ! Mg2+(g) + 2Cl– (g) (3) Mg(s) + Cl2(g) ! Mg(g) + Cl2(g) (4) Mg(g) + Cl2 (g) ! Mg(g) + 2Cl (g) (5) Mg2+(g) + 2Cl– (g) ! MgCl2(g) (A) (1) and (3) (B) (1), (3), and (4) (C) (5) (D) (2) and (5) (E) (1), (2), and (5) 25. Which is a FALSE statement? (A) The lattice energy of LiCl has a larger magnitude than that of NaCl. (B) The lattice energy of CaO has a larger magnitude than that of NaCl. (C) Na reacts with # Cl2 to form NaCl molecules. (D) Some ionic compounds may not conduct electricity when dissolved in water. (E) Lattice energy decreases as ionic radius increases as long as charge remains constant.