What is the formal charge of the oxygen atom in the following structure (all bonds and lone pairs are drawn):

Draw the Lewis structure for the following molecular formulas.

(u) NH₄⁺

Draw a Lewis structure for each of the following:

b. CO₃²⁻

Calculate the net charge of the molecule

Calculate the totalchargeof themolecule

An atom with a formal charge does not necessarily have more or less electron density than the atoms in the molecule without formal charges. We can see this by examining the potential maps for H₂O, H₃O⁺, and HO⁻.

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c. Which atom bears the formal positive charge in the hydronium ion?

d. Which atom has the least electron density in the hydronium ion?

An atom with a formal charge does not necessarily have more or less electron density than the atoms in the molecule without formal charges. We can see this by examining the potential maps for H₂O, H₃O⁺, and HO⁻.

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a. Which atom bears the formal negative charge in the hydroxide ion?

b. Which atom has the greater electron density in the hydroxide ion?

Looking ahead in Chapter 3, we describe how the formal charge on an atom can be used to predict the number of lone pairs. Given the charge, or lack of charge, on each atom, fill in the electron pairs.

(c)

By moving an electron pair, draw a better Lewis structure that minimizes formal charges.

(b)