Ch. 9, 11, & 9.7; 11.8; 23.5 - 23.6 solids, bonds II, & IMF    test           [100 points]     AP Chem

Academic Honesty:   The answers on this test are my own and I am using only the allowed set of notes as described in the syllabus.  I have not discussed the test questions with anyone before or during the test nor have I seen the test questions prior to the exam.  If you violate any of the preceding items or do not sign, your semester grade is a F.

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1.  In the application of molecular orbital theory to a diatomic molecule, e.g. H2   [figure 9.32 in your textbook], where are the electrons located in the __ and what is the significance / consequence of this location ?  [10 points]

 a. bonding molecular orbital

 b. antibonding molecular orbital

2. Use band theory to rationalize the basis in the difference in electrical conductivity between an insulator, conductor, and semiconductor.  [15 points]

3. In regards to SF4,   [10 points]

a.  Sketch the shape of the molecule

b.  What is the name of the shape of the molecule and the bond angle(s) in the molecule.

4. What is the polarity (i.e. polar- versus nonpolar- compound) of water versus carbon dioxide ?  Justify / rationalize your answer.  [10 points]

5. Use valence bond theory to describe the bonds in __.  If hybrid orbitals are involved, then (i) identify the hybrid orbital, (ii) why a hybrid orbital is needed, (iii) rationale for that specific hybrid orbital, and (iv) describe the formation of the hybrid orbital from the appropriate atomic orbitals.  [20 points]

a.  water

 b. carbon dioxide

6.  Describe the basis of separating the blue- versus red- dye in the chromatography lab using an isocratic elution protocol; in your answer, use concepts involving intermolecular forces and refer to the below molecular structures (not shown); specifically,  __.   [20 points] 

a.  basis of the relative order of the dye elution.

b. role of the alcohol in the elution process

7. Old topic:  in regards to the mass spectrometer / spectrum,  [15 points]

a. Sketch the mass spectrum of a hypothetical sample containing 10% 210Pb, 20% 200Pb, and 70% 206Pb.  Label both axis; include numerical values on both axis, set maximum signal to 100 units on the vertical axis.

b. Describe the different parts of a masss spectrometer and its role / function in getting the mass spectrum of a sample.