Chemistry Lab Handout 12   "Molecular Model Polarity and Geometry"

 

Your Name:    ___________________________________ Role:______________

 

Lab Partners: ________________Role:_____   ________________Role:_____

 

Problem:  How can you determine the polarity and geometry of a

          molecule?

 

Hypothesis:   _______________________________________________________

 

     _________________________________________________________________

 

     _________________________________________________________________

 

Materials:    Molecular Model Building Kit

 


          Carbon (black) 6                  Oxygen (red) 2

 


          Hydrogen (yellow) 10                  Chlorine (green) 4

 


          Nitrogen (blue) 2                 Sulfur (red) 0

 


          Bromine (orange) 1                Germanium (black) 0

 


          Fluorine(green) 0                 Iodine(green) 0

 


          Silicon(black) 0                  Tellurium (red) 0

          Antimony(blue) 0               B  Boron (wood colored) 1

 


8 long sticks, 20 short sticks & 8 springs

 

Caution:  (no special concerns)

 

Procedure:

1. Assemble each molecule and fill out the observations table. Use the

     key above for drawing structural model.

2. Rules for building:

     A. All holes must be filled.

     B. Use springs only when the bond must be curved to fit.

3. On your observation table include the structural drawing of the

     molecule, the electron dot (Lewis) structure, the bond angles,

     the shape of the molecule, the hybridization of the central atom,

     whether there are polar bonds and whether the molecule is polar.

4. Complete all the observations for a single molecule before going on

     to the next molecule. 

 

1.   H2S       2.   SiCl4          3.   SbI3      4.   Cl2GeO

 

5.   OBr2      6.   CS2            7.   C2Cl3H    8.   TeI2

 

9.   BCl3      10.  CH4            11.  NH3       12.  H2O

 

 

 

 

Observations:

On a separate piece of paper (landscape orientation) fill in your observations table.

 

Data: (none)

 

Diagram:

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conclusion:   _______________________________________________________

 

     _________________________________________________________________

 

     _________________________________________________________________

 

Questions:

1. What are the bond angles in the following shapes:

 linear, bent, trigonal planar, trigonal pyramidal, tetrahedral?

2. Why do some molecules have polar bonds but end up being non-polar molecules?

3. Compare and contrast trigonal planar and a trigonal pyramidal

    molecules?

4. What two factors must be true for a molecule to be polar?

 

Answers: