Chapter 4.2 - Types of Bonds, Lewis Structures, and VSEPR - Answers

6. What is an expanded valence? Included a labelled diagram in your explanation.

7. Draw the Lewis structure for: (a) CH2O

(b) BrF5

(c) NO3-

(ignore the + and – in the diagram) (this structure should have square brackets around it with a – on the outside of the bracket)

(d) CCl2O

(e) XeO4 (this contains co-ordinate covalent bonds)

8. Formic acid, or methanoic acid, HCOOH, is found naturally in ant venom. Synthesized formic acid is used for its antibacterial and preservative properties in a variety of animal feeds, among other uses. Given that carbon is the central atom of the molecule, with hydrogen, oxygen, and hydroxide (O—H) groups, draw its Lewis structure.

9. Predict the shape and bond angles for the central atom in the following molecules. (the first one has a guided answer) (a) CF4 Lewis Structure

Number of lone pair electrons ___0____. Number of different bonds (bonding sites) ___4___. (note: single, double, and triple bonds only count as one bonding site.) VSEPR Shape __Tetrahedral_____________. Draw VSEPR shape, indicating bond angles.

(b) HCN

(c) PbCl3

(d) XeF4

(e) PCl5

(f) PCl6-