1. Which of the following is the correct Lewis Structure for the molecule sulfur tetriodide, SI 4? A.

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1 CHM 1045-All ections Exam 3 Practice Exam Fall 2013 Unit 3 Thermochemistry, Atomic tructure, & Bonding Chapters 6-10 ======================================================================= 1. Which of the following is the correct Lewis tructure for the molecule sulfur tetriodide, 4? A. B. C. D. E. 2. A gas is said to be non-ideal when it does not follow the ideal gas law. Which of the following statements correctly describe a flaw in one of the KMT assumptions that would explain why a gas behaves in a non-ideal manner? i. at low pressure the attractive forces between molecules become significant ii. at high pressure the volume of the molecules is significant iii. small number of moles causes the value of R to change D. i and iii E. ii and iii Page 1

2 3. Hydrogen is found to effuse at a rate that is 4.34 times faster than an unknown gas. Which of the following is the unknown gas? A. CO B. N 2 O C. Ne D. Kr E. F 2 4. Which of the following electron configurations is/are correct? i. Zn 2+ : [Ar]3d 10 ii. Os:[Xe]6s 2 5d 6 iii. Fe 3+ : [Ar] 4s 2 3d 3 D. i and ii E. i and iii 5. Which of the following molecules would be polar? A. CCl 4 B. MgF 2 C. F 3 D. F 5 + E. XeF 4 6. A sealed container with a moveable piston contains a gas with a pressure of 1589 torr, a volume of 3.15 L, and a temperature of 85.0 C. What would the pressure be if the volume were reduced to 1.55 L and the system were cooled to a temperature of 42.0 C? A torr B torr C torr D torr E torr 7. How many unpaired electrons will a Co 2+ ion have? A. 0 B. 3 C. 2 D. 7 E. 5 Page 2

3 8. A tank contains 13.0 g of oxygen and 6.50 g of helium at a pressure of 39.5 atm. What is the partial pressure of the oxygen? A atm B atm C atm D atm E atm 9. Which of the following molecules would have see-saw molecular geometry? A. Br 3 B. CCl 4 C. F 4 D. Cl 4 E. O Which of the following molecules is NOT polar? A. Br 3 B. H 2 O C. NH 3 D. BrF 3 E. F Which of the following atoms can violate the octet rule by either underfilling or overfilling? i. Ne ii. F iii. Br iv. i D. i and iii E. iii and iv Page 3

4 12. Using the bond energies provided below, estimate H rxn for the reaction given: CO 2 + 2H 2 O > CH 4 + 2O 2 Bond Bond%Energy%(kJ/mol) C3H 414 C3O 360 C=O 799 O-O 142 O=O 498 O-H 464 H-H 436 A kj B kj C. 292 kj D. 352 kj E. 802 kj 13. What is the formal charge on the oxygen atom that is marked by the arrow in the structure below? A. 1 B. 0 C. 2 D. +1 E What volume would carbon dioxide occupy if g CO 2 were held at C and a pressure of 2.65 atm? A L B L C L D L E L Page 4

5 15. An unknown gas is weighed and found to have a density of g/l at a temperature of 10.0 C and a pressure of atm. Which of the following is the best choice for the identity of the gas? A. CO 2 B. NO 2 C. N 2 D. O 2 E. NO 16. The pressure in a system is found to be 2.45 atm. What would the pressure be if the number of moles of gas were tripled and the volume were cut in half while maintaining constant temperature? A atm B atm C atm D atm E atm 17. Which of the folllowing statements is/are true? i. {28,2,0,-1/2} is an allowed quantum number set ii. {5,2,-2,1/2} describes an electron in an 4-lobed orbital iii. {2,1,2,-1/2} describes an electron in a p orbital D. i and ii E. i and iii 18. How many electrons can have the quantum number set n = 5 and m l = 2? A. 2 B. 4 C. 6 D. 8 E Which of the following statements is/are true? i. volume would increase if the moles of gas are increased at constant T & P ii. volume would decrease if the pressure of gas is increased at constant T & moles iii. volume would increase if the pressure of gas is increased at constant T & moles D. i and ii E. i and iii Page 5

6 20. Which of the following statements is/are true regarding first ionization energy trends? D. i and ii E. i and iii i. lithium has a lower ionization energy than nitrogen ii. nitrogen has a lower ionization energy than oxygen iii. boron has a lower ionization energy than beryllium 21. Which of the following quantum number sets, {n, l, m l } describe the orbital shape shown below? A. {3,3,0} B. {2,1,1} C. {4,0,0} D. {5,3,-2} E. {1,1,0} Page 6

7 Answer Key for Test F13 Practice Exam 3, 11/19/13 No. in No. on Q-Bank Test Correct Answer D B E A C A B D C A E E A D D A D C D E D Page 1

8 tatistics for Test F13 Practice Exam 3. Total questions: 21 Key Word Total Difficulty Level Total None Total None 8 None 0 Essay Quantum numbers 1 Easy 4 hort Answer Orbital shape and QN 0 Moderate 10 Fill in Blank e- configuration 0 Hard 6 Matching anomolous e- config 0 Max Diff 1 dentification properties wrt PT 0 True or False Radius Trends 0 Multiple Choice st & higher Es 0 Matching Question EA trends onic e-configuration Atomic and ionic radium trends atomic Lewis Diagram ions and octet Covalent bonds Polarity of bonds Lewis tructures Formal Charge Resonance tructures Bond dissociation energies e- geometry molecular geometry polarity hybrid orbitals sigma vs. pi bonds pressure and units apply gas laws ideal gas law gas stoichiometry Daltons law of Part. press Molar volume of a gas KMT Graham's Law Non ideal gases 0