Chem 121 EXAM IV Name: Spring 2014 CCBC-Catonsville (Thurs 5/1/14)

Transcription

1 Spring atonsville (Thurs 5/1/14) *** ALWAYS ANSWER IN FULL SENTENES! *** On numerical problems, you MUST show your set ups. When dimensional analysis is specified, you MUST set up the problem by dimensional analysis. *** Use your time wisely. Do not get stuck on one question. *** Answer each question carefully, with thought and with confidence! Do not stop to check over your work until you have worked through the entire exam. TOTAL YOUR PAGE SORE SORE POSSILE TOTAL 100 onus p.5 4 Adjusted total to Exam IV = urrent ourse Total = (including 4 Exams, 10 Wiley, 4 Paper W & 14 Quizzes)

2 Spring 2014 Page 1 1. (4 pts) For n = 4, what are the allowed values of quantum number l? Ans. ow many electrons in an atom can have quantum numbers n =6 and l = 2? Ans. 2. (6 pts) Fill in the electrons for ground state for the V 2+ ion. E 3d 3p 3s 2p 2s 1s 4p 4s Write the FULL electron configuration for V 2+ on the blank below: Electron configuration: 3. (2 pts) Give the electron configuration of tin USING TE ORE METOD. 4. (2 pts) Give the electron configuration of ONLY the valence electrons of lead. 5. (2 pts) Give the electron configuration of ONLY the valence electrons of nitride ion. 6. (2 pts) Give the formula of an cation that is isoelectronic with a +2. Ans. 7. (2 pts) onsider ground state tin atom. ircle one: paramagnetic or diamagnetic 8. (2 pts) Give the electron configuration of the electrons that shield the nuclear charge from the outer shell electrons of the bromine atom.

3 Spring 2014 Page 2 9. (15 pts) Give the Lewis structure for each of the following. If there are resonance structures, give all of them and then circle the most stable one. Resonance hybrid is not necessary. Remember to include the formal charges. a) a(o) 2 b) XeF 3 + c) PO (4 pts) State the geometry of two of the species in Question #8 above (using conventional terminology) + b) XeF 3 (a) is not required. c) PO 4 3

4 hem 121 EXAM IV Name: Spring 2014 Page (4 pts) a) Fill in the formal charges (if any) of the following structures and IRLE the most stable structure: : N N O N O N : : : b) Are these isomers or are they resonance structures? ircle one: isomers or resonance structures 12. (16 pts) Fill in the blanks for each of the following. You can use the bottom of the page as scratch paper. That section of the page will not be graded. A A A A hybridization of A: molec. geometry: bond angles Assuming is more electronegative than A, determine the molecular polarity: polar or nonpolar?

5 Spring 2014 Page (6 pts) (a) Fill in formal charges (if any) and (b) give the resonance hybrid for the following resonance structures: : O: O : O: O : Resonance hybrid: 14. (5 pts) onsider the structure on the right. a) What is the bond angle of O? Ans. b) What is the bond angle of O =? Ans. c) What is the bond angle of N? Ans. O N 15. (4 pts) The anion below is surrounded by 2 water molecules. Draw the Lewis structure of two water molecules showing how they would orient themselves around a bromide ion. r

6 Spring 2014 Page 5 (4 pts each) MULTIPLE OIE: IRLE the one best answer for each of the following: 16. Which is larger? A. a 2+. K +. They are the same in size. 17. Which has the larger magnitude of lattice energy? A. MgO. Kl 18. Which is the largest? A.. N 19. ased on which rule is this forbidden? 3p A. Aufbau Principle. und s rule. Pauli Exclusion Principle D. Octet Rule 20. Which has the higher ionization energy? A. nonmetals. metals 21. Where does the extra large increase in ionization energy occur for the beryllium atom? A. between the first and second ionization energy.. between the second and third ionization energy.. between the third and fourth ionization energy. D. between the fourth and fifth ionization energy. onus Points: (1 pt) Make sure you have your full name on all pages, front and back. (3 pts) Draw the structures of 2 water molecules with correct bond angles showing how they would attract each other and with an arrow point to EXATLY what is broken when we boil water.