Form Code X. 1. Which of the following transitions in a hydrogen atom would emit the longest wavelength photon?

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1 Form Code X NAME CHM 2045, Summer 2018 Exam Packet Instructions: Do your best and don t be anxious. Read the question, re-read the question, write down all given or valuable information, and write down what you want to find. 1. Which of the following transitions in a hydrogen atom would emit the longest wavelength photon? (1) n = 1 to n = 2 (2) n = 3 to n = 2 (3) n = 5 to n = 1 (4) n = 2 to n = 8 (5) n = 6 to n = 5 2. Select the false statement: (1) Photons of green light have greater energy than photons of red light (2) Light emitted by an n = 4 to n = 2 transition will have greater energy than light from an n = 3 to n = 1 transition (3) The energy of a photon is directly related to its frequency and inversely related to its wavelength (4) There are only two subshells associated with the n = 2 shell of an atom (5) In accordance with Hund's rule, a ground-state phosphorus atom contains three unpaired electrons in its 3p subshell 3. Which choice contains a possible set of quantum numbers (n, l, ml, ms) for the first electron removed from a ground-state vanadium atom? (1) 4, 0, 0, +½ (2) 4, 1, 0, ½ (3) 3, 2, 0, +½ (4) 3, 1, 1, +½ (5) 4, 2, 2, ½ Which of the following quantum numbers (n, l, ml) are not a possible combination? 1) 2,1,0 2) 1,0,0 3) 3,1,-2 4) 3,2,2 5) 2,0,0

2 5. A certain light bulb consumes 200 J of energy per second. If a light bulb converts all of this energy to 500 nm light, how many photons are produced each second? 1) 5.0 x ) 200 3) 5.0x10-7 4) 5.0x ) Which statement(s) is/are TRUE? I. In a vanadium atom, a 4s electron has higher energy than a 3d electron. II. The number of orbitals in a given p subshell is 5. III. The 3px, 3py, and 3pz orbitals look the same, but they point in different directions. IV. In a strontium atom, the 3px and 4px orbitals have the same size and shape. (1) III, IV only (2) II, III only (3) II, III, IV (4) I, III only (5) I, III, IV 7. Enormous numbers of microwave photons are needed to warm household samples. A bowl of soup containing 400g of water is heated in a microwave oven from 20.0 C to 98.0 C using radiation with wavelength 122 mm. Assuming that the specific heat capacity of the soup is the same as that of water (4.184 J/g C) and no heat loss to the bowl, which choice is closest to the number of photons absorbed? 1) 4.0*10-6 2) 8.0* ) 4.0*10 6 4) 8.0* ) None 8. Which of the following atoms are paramagnetic in their ground state? S, Cr, Sr, Hg (1) Only Cr (2) Only Sr (3) S and Cr (4) S and Sr (5) Sr and Hg 9. Select the false statement below: (1) Fe has 2 outer electrons, 8 valence electrons, and 18 core electrons (2) Fe 2+ is more paramagnetic (has more unpaired electrons) than Fe 3+ (3) Fe 3+ is isoelectronic with Mn 2+ (4) none of these ions (Fe 2+, Fe 3+, Mn 2+ ) have any electrons in the 4s subshell (5) Fe 3+ is predicted to be a stronger potential oxidizing agent (can be reduced more) than Fe 2+

3 10. Rank the following five ions in order of increasing ionic radius: Rb +, In 3+, Al 3+, Sr 2+, Ga 3+ (1) In 3+ < Sr 2+ < Rb + < Al 3+ < Ga 3+ (2) Rb + < In 3+ < Al 3+ < Sr 2+ < Ga 3+ (3) Ga 3+ < In 3+ < Al 3+ < Sr 2+ < Rb + (4) Al 3+ < Ga 3+ < In 3+ < Sr 2+ < Rb + (5) Al 3+ < Ga 3+ < In 3+ < Rb + < Sr Consider the ground state electron configuration of chromium and select which of the following oxides is least likely to appear as a compound. (1) CrO (2) Cr2O3 (3) CrO2 (4) Cr2O7 (5) CrO3 12. Predict the most acidic and the most basic oxide from among the following: Al2O3 SiO2 CO2 P4O10 MgO Rb2O N2O5 (1) most acidic = N2O5; most basic = Rb2O (2) most acidic = Al2O3; most basic = MgO (3) most acidic = CO2; most basic = SiO2 (4) most acidic = P4O10; most basic = Rb2O (5) most acidic = N2O5; most basic = MgO 13. In the properly-drawn Lewis structure for water, which of the following is true? (1) the O atom is hybridized sp 2 around which is exhibited a bent geometry (2) the H atom is hybridized sp 2 and its hybrid orbitals are oriented in a linear geometry (3) the lone pairs on the Oxygen exist in a hybridized sp 3 orbital (4) the overall molecule is planar (5) None of the Above 14. Which ionic compound below is composed of ions that are isoelectronic with each other? (1) BaBr2 (2) ScCl3 (3) CdI2 (4) ZnO (5) NaCl 15. Which species is correctly matched with the hybridization at the central atom? (1) SeF4, sp 3 (2) OF2, sp 2 (3) NF3, sp 3 (4) KrF2, sp (5) IF5, sp 3 d

4 16. Which of the following fluorine containing compounds is predicted to be nonpolar? (1) SeF4 (2) OF2 (3) NF3 (4) KrF2 (5) IF5 17. Which one of the following is a nonpolar molecule with polar bonds? (1) CH2O (2) PH3 (3) SF4 (4) CCl4 (5) CH3OCH3 18. Arrange the following elements in order of increasing first ionization energy: F, Be, O, N, C (1) F < O < N < C < Be (2) Be < N < C < O < F (3) Be < C < O < N < F (4) O < F < N < Be < C (5) Be < C < N < O < F 19. The active ingredient in super-glues is methylcyanoacrylate. How many sigma (σ) and pi (π) bonds are in one molecule of methylcyanoacrylate? (hint : don t forget to consider the carbon-hydrogen bonds in the molecule) (1) 7 σ, 3 π (2) 7 σ, 4 π (3) 12 σ, 3 π (4) 12 σ, 4 π (5) 16 σ, 4 π 20. What respective type of hybridization is shown by the central atoms in CHF3 and XeF3 +? (1) sp2, sp2 (2) sp3, sp3 (3) sp2, sp3d (4) sp3, sp3d (5) sp3, sp3d2

5 21. In molecular orbital treatment of diatomic molecules, what type of molecular orbital(s) are created by mixing an s orbital from one atom with a p orbital from the other atom? (1) only σ (2) only π (3) σ and π (4) σ and σ* (5) π and π* 22. Which of the following molecules is/are incorrectly paired with their molecular geometries? I. NH3, trigonal pyramidal II. OF2, angular III. XeF4, tetrahedral IV. SeF4, square planar 1. I only 2. I and II 3. III and IV 4. I, II, III, and IV 5. None of the Above 23. Calculate the ΔHf of SrCl2(s), given the following thermochemical equations. Sr(s) Sr(g) ΔHvap/sub = kj/mol Sr(g) Sr+ (g) + e- IE1 = 549 kj /mol Sr + (g) Sr 2+ (g) + e- IE2= 1064 kj /mol Cl2(g) 2Cl(g) BE = 243 kj /mol Cl(g) + e- Cl - (g) EA = -349 kj /mol Sr 2+ (g) + 2Cl - (g) SrCl2(s) LE = kj /mol (1) kj (2) kj (3) kj (4) kj (5) kj GOOD LUCK ON THE EXAM, and remember to love your moles: all x 1023 of them! -Broward Teaching Center