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UL Lafayette CHEM 107 - Study Notes

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LAST NAME, FirstCHEM 107 (Spring-2007)Exam 3 (104 pts)Name: ------------------------------------------------------------------------, Clid # ------------------------------ LAST NAME, First(Circle the alphabet segment of your LAST NAME): A & B C-G H-L M-P R-Z Please answer the following questions:Part I: Multiple Choices (52 pts: 13 @ 4 pts each + 4 pts bonus). Circle the ONE best answer:1. An Co3+ ion isa) paramagnetic with four unpaired electrons b) diamagnetic with zero unpaired electrons c) paramagnetic with two unpaired electronsd) paramagnetic with one unpaired electron 2. The orbitals of 2p electrons are often represented as being a) elliptical b) tetrahedral c) dumbbell shaped d) spherical3. Which set of quantum numbers is correct and consistent with n = 4? a) ℓ = 3, mℓ = -3, ms = +½ b) ℓ = 4, mℓ = +2, ms = -½ c) ℓ = 2, mℓ = +3, ms = +½ d) ℓ = 3, mℓ = -3, ms = +1 4. The ground state electron configuration of lead, Pb (Z = 82) isa) [Xe] 5d10 6s2 6p2b) [Xe] 4f14 6d10 6s2 6p2c) [Xe] 4f14 5d10 6s2 6p2d) [Xe] 6s2 6p25. The maximum number of electrons that can occupy an orbital labeled 4px isa) 6 b) 4 c) 2 d) 3 6. The ground state electron configuration of chromium atom, Cr (Z = 24) is a) 1s2 2s2 2p6 3s2 3p6 4s2 3d4 b) 1s2 2s2 2p6 3s2 3p6 4s1 3d5 c) 1s2 2s2 2p6 3s2 3p6 3d6 d) 1s2 2s2 2p6 3s2 3p6 4s2 4p4 7. Which of the following has the highest ionization energy?a) Xe b) K c) Cl d) Ne8. When the three elements S, Se and Cl are arranged in order of increasing atomic radius, which is the correct order?a) Se < S < Cl b) S < Cl < Se c) S < Se < Cl d) Cl < S < Se 19. Which of the following bonds is considered to be the least polar?a) O-F b) C-F c) N-F d) Si-F10. Which of the following electromagnetic radiation has the shortest wavelength? a) X-ray b) Visible light c) γ-rays d) Infrared 11. Which of the following isoelectronic species would have the smallest radius? a) Na+b) Al3+ c) F-d) N3-12. Which compound has a triple bond? a) O2b) BrCNc) BeF2 d) CO213. Which of the following molecules is most likely to have bond angle close to 109°?a) XeF4b) SF4c) CF4d) NF314. Which of the following molecules is classified as predominantly ionic?a) SeO2 b) Cl2O7d) P4O10d) SrS Part III. Bonding (30 pts):1. (20 pts) Draw the Lewis structure of the following molecules or ions?a) SF4 b) CO32-c) XeF4d) O32a) SF4b) CO32-c) XeF4d) O32. (10 pts) Draw the Lewis structure for the laughing gas dinitrogen oxide, N2O (NNO), draw the resonance structures, if there is any then: predict: a) number σ and π bonds b) The molecular shape of the ionPart III. Calculations (18 pts) Show all work for full credit. Please express all answers with the proper units and correct number of significant figures.1. (12 pts) a) Calculate the wavelength in nanometers in the H-atom spectrum that arises from the electron transition of n = 5 to n = 2.b) In what spectral region does this transition occur? --------------------------------------------------c) Is energy absorbed or emitted? --------------------------------------------------3λ (nm) = Lewis Structure & resonance structures (if any)a) Molecular shape: ------------------------b) # of σ bonds ---------- and # of π bonds -----------c) # nonbonding e’s on the central atom -----2. (6 pts) Calculate the ground state energy, in joules of the electron in the H atom.Exam 3 –Spring 2007You will have 55 minutes to complete this exam. The exam has 3 pages plus the Periodic Table and Reference page. When you are told to do so, tear off the Periodic Table cover sheet and use as required during the exam. 11H1.01Periodic Table of the Elements2He4.0023Li6.944Be9.015B10.816C12.017N14.018O16.009F19.0010Ne20.18311Na22.9912Mg24.3013Al26.9814Si28.0815P30.9716S32.0617Cl35.4518Ar39.95419K39.120Ca40.0821Sc44.9622Ti47.8823V50.9424Cr52.0025Mn54.9426Fe55.8527Co58.9328Ni58.6929Cu63.5530Zn65.3831Ga69.7232Ge72.5933As74.9234Se78.9635Br79.9036Kr83.80537Rb85.4738Sr87.6239Y88.9140Zr91.2241Nb92.9142Mo95.9443Tc(98)44Ru101.145Rh102.946Pd106.447Ag107.948Cd112.449In114.850Sn118.751Sb121.852Te127.653I126.954Xe131.1655Cs132.956Ba137.357La138.972Hf178.573Ta181.074W183.875Re186.276Os190.277Ir192.278Pt195.179Au197.080Hg200.681Tl204.482Pb207.283Bi209.084Po(209)85At(210)86Rn(222)787Fr(223)88Ra226.089Ac227.0104Rf(261)105Db(262)106Sg(263)107Bh(262)108Hs(265)109Mt(266)110Uun(269)111Uuu(272)112Uub(277)58Ce140.159Pr140.960Nd144.261Pm(145)62Sm150.463Eu152.064Gd157.265Tb158.966Dy162.567Ho164.968Er167.369Tm168.970Yb173.071Lu175.04PREFERENCE SHEET FOR CHEM 107Equations and Constants:ν = RH/h [1/(nlo)2 – 1/(nhi)2] En = -RH/n2 E = h ν c = λ νRH = 2.180 x 10-18 J h = 6.626 x 1034 J.s c = 3.00 x 108

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