Ch. 8 & 9 bonds & molecular geometry test                    [70 points]                             AP Chem

For problems involving calculations, show the relevant equation (or formula and conversion factor(s)), show your work in an organized manner, put the proper units in your calculations / answer, and 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 SF4 ,        [15 points]

a.  draw its Lewis structure

b.  sketch the molecule; include the name of the shape of the molecule & its bond angle(s)

c.  is it a polar of nonpolar molecule ?  justify your answer.


2.  What is the application & basis of VSEPR ?  [5 points]

3.  In regards to SF4 ,  [hint:  see #1; 25 points]

a.  rationalize the need for a hybrid orbital in the central atom.

b.  identify the hybrid orbital in the central atom.  justify your choice.

c.  use valence bond  theory to describe the bonds in the molecule.

d.  describe the process to obtain the desired hybrid orbital in the central atom.


4.  In regards to carbon dioxide,  [15 points]

            a.  draw all Lewis structures.

b.  determine the formal charges on all atoms in the preceding Lewis structures.

c.  Pick the “best” Lewis structure; justify your choice.


5.  old topic:  chemical reaction.   [10 points]

a.  K  +  H2 O  ->  __________________

b.  Al  +  Br2   ->   ___________________

c.  K2 O  +  H2 O  ->   ________________

d. CaO  +  HCl  ->   _________________

e.  Li  +  O2  ->  ____________________