1. A Review of General Chemistry

Which set of formal charges correctly corresponds to the three major resonance forms of $N_{2}O$ (nitrous oxide), written as $N-N-O$?

Given the Lewis structure of ${\mathrm{CO}}_2$, determine the formal charge on each atom.

a. Draw a Lewis structure for each of the following:

b. Draw a structure for each of the species that shows approximate bond angles.

c. Which species have no dipole moment?

1. CH₃N₂⁺

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)

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

(a)

Draw the Lewis structure for the following ions. Be sure to calculate the formal charge of each atom to confirm that your structure is correct.

(c) BH₄^-

Calculate the formal charge of the indicated atom in the following molecules or ions.

(f)

Calculate the formal charge of the indicated atom in the following molecules or ions.

(e)

Draw the Lewis structure for the following molecules. Be sure to calculate the formal charge of each atom as a way of confirming your structure is correct.

(c) CF₄