Chemistry Department CHM 1220/1225 Winter 2006 Sample Exam II Givens You will be given the table of electronegativities and a periodic table. Note: You will not be given the Molecular Orbital Energy Diagram. Questions For #1 –5 below be sure to indicate the number of valence electrons, bonding electrons and nonbonding electrons. Also be sure to indicate the formal charge of each atom. 1. Write the best Lewis formula for SO2. Include resonance structures if they are needed.. 2. Write the best Lewis formula for BeF2. Include resonance structures if they are needed.. + 3. Write the best Lewis formula for XeF5 . Include resonance structures if they are needed. –– 4. Write the best Lewis formula for HCO2 Include resonance structures if they are needed. 5. For each of the structures in #1–5, indicate the polarity of any polar bond. 6. Using the structure from #1 and #2, predict whether each will be polar or nonpolar, whether the dipole moment will be zero or nonzero. 7. Complete the chart below: Arrangement of pairs 2– O O C O + F Cl F F F N H H H Molecular Geometry (Shape) 8. Complete the chart below: Hybridization of the central atom Identify each bond as a σ-bond or π-bond 2– O O C O + F F Cl F F N H H H 9. a. Write the molecular orbital electron configuration for the NO molecule. You may omit the KK Shell. b. What is the bond order of the NO molecule? + c. What is the bond order of the NO molecular ion? + d. Which has a shorter bond, NO or NO ? 8. Complete the following table for types of solids: SOLID TYPE STRUCTURAL UNIT ATTRACTIVE FORCE BETWEEN STRUCTURAL UNITS EXAMPLE 10. Draw the graph showing the temperature of a substance as heat is added. Label each phase change and the relevant temperatures. (i.e. Temperature is on the vertical axis, Energy/Heat Added is on horizontal axis. Also review your Quizzes on Chapters 9 and 10, particularly on conceptual material.