Electron Dot Formulas (or Lewis dot structures) Shape, and

							                           Electron Dot Formulas (or Lewis dot structures)
                                   Shape, and Polarity Worksheet	
  
	
  
1. For the following molecules and polyatomic ions draw the electron dot structure, determine the molecular shape
using the Table of Shapes, determine if the bonds are polar or not, and determine if the entire molecule is polar or not:

                                       -   -    +
               PCl3, CO, CH2F2, NO3 , OH , H3O , HCl

2.             Really cool interactive tutorial at http://www.wisc-online.com/objects/index_tj.asp?objID=GCH6404
               BUT stop at page 20, don’t do the exceptions!!!
	
  
3. Go to http://www.stolaf.edu/depts/chemistry/courses/toolkits/123/js/lewis/

       And choose only these molecules from the top left menu:

           1.     Ammonia
           2.     Carbon dioxide
           3.     Hydrogen fluoride
           4.     Hydrogen peroxide
           5.     Methyl fluoride
           6.     Molecular fluorine
           7.     Molecular nitrogen
           8.     Ozone
           9.     Phosphine
           10.    Water

Answers from number 1

PCl3, has P in the middle with single bonds to each Cl, each Cl has 3 lone pairs and P has one lone pair, total
electrons in the structure is 26, shape is trigonal pyramid, bonds are polar, molecule is polar

CO, has a triple bond between the C and O, there is one lone pair on the C, there is one lone pair on the O, total
electrons in the structure is 10, shape is linear, bond is polar, molecule is polar

CH2F2, has C in the middle with four single bonds, each H is connected to the C with a single bond and no lone pairs
on the H, each F is connected to the C with a single bond and each F has three lone pairs, total electrons in the
structure is 20, the shape is tetrahedral, the C-F bonds are polar, the C-H bonds are nonpolar, the molecule is polar
overall
           -
NO3 , has N in the middle with single bonds to two of the O’s and a double bond to one of the O’s, the single bonded
O’s have three lone pairs while the double bonded O has two lone pairs, the N has zero lone pairs, total number of
electrons in the structure is 24, shape is trigonal planar, bonds are polar, the polyatomic ion is polar because a double
bond does not “cancel” with single bonds. So it is not symmetrical.
       -
OH , has a single bond between O and H with three lone pairs on the O, no lone pairs on the H, total number of
electrons in the structure is 8, shape is linear, bond is polar, polyatomic ion is polar
           +
H3O , has O in the middle with three single bonds to the H’s, there are no lone pairs on the H’s, but O has one lone
pair on it, the total number of electrons in the structure is 8, shape is trigonal pyramid, bonds are polar, molecule is
polar

HCl has a single bond between the H and Cl, with no lone pairs on the H but three lone pairs on the Cl, total number of
electrons is 8, shape is linear, bond is polar, molecule is polar