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Lewis Structures and VSEPR (valence shell electron pair repulsion)

Lewis Structures and VSEPR (valence shell electron pair repulsion). See attached file for full problem description.

1. Listed in the attached document are electron dot formulas for several simple molecules and ions. All valence electrons are shown; however, electrical charges have been omitted deliberately.

Which of the structures actually bear(s) a positive charge?

2. Which of the structures attached would be trigonal planar?

3. What would be the spatial arrangement of the atoms only of the methyl anion, : CH3-


Solution Preview

Lewis Structures and VSEPR (valence shell electron pair repulsion)

Please see attached file.


1. Both, NH4+ and H3O+ bear a positive charge. How do we know? NH3 is the molecule ammonia. It is neutral. Ammonia is a base. It reacts with acids such as H+ to form the ammonium ion, NH4+. The same thing can be said of water. Although H2O is neutral, it can act as either an acid or a base. In this case, it acts as a base, reacting with H* forming the hydronium ion, H3O+.

If we were to do formal charge calculations, they would go like this:

FC = (group number) - (number of bonds) - (number of unshared ...

Solution Summary

The solution answers three questions on lewis structures. Lewis structures and the valence shell electron pair repulsion is analyzed.