Ch. 8 & 9, 11.8, 23.5 – 23.6 chemical bonds & solid     test               60 points                                  AP Chem

Show your work in an organized manner, include (i) any relevant equation (or formula), (ii) conversion factor(s), (iii) put the proper units in your calculations and answer, and (iv) have the proper number of significant figures in your answer.

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.

                                                                                                Signature:  ___________________

 1. In regards to PCl5, SF4, and ClF3,  [20 points]

a.  Sketch the shape of each molecule

b. What is the name of the shape of the molecule

i. PCl5 = ________________________________

ii. SF4 = __________________________________

iii.  ClF3 =  ________________________________

2. What is the relative bond angles between these molecules; justify / rationalize your answer.

3. In regards to H2SiO (Si is the central atom),  [20 points]

a. Sketch the molecule to show its shape.

b.  using valence bond theory, describe the bonds in the molecule.

c. If hybrid orbital(s) are involved, then  ___; otherwise, justify why hybrid orbital(s) are not present.

i. identify and justify / rationalize the hybrid orbitial(s) in the molecule

ii.describe its formation

4. Rationalize the difference in the electrical conductivity (or resistance) between a conductor versus a semiconductor using band theory.  [5 points]

5.  In regards to molecular orbital theory, what is the role / function of electrons in an antibonding orbital versus bonding orbital ?  [5 points]

6. Old topic:  Beer’s law lab.  [10 points]

a. what is the basis / rationale of selecting a specific wavelength for your measurement ? 

b.  the Cu(NO3)2 solution is blue and the absorbance of blue light by the Cu(NO3)2 solution was about zero; justify / rationalize this observation.