Leader: Grant DeRocher Ch 7.3-7.5 Course: Chem 167 Supplemental Instruction Instructor: Houk Iowa State University Date: 02/26/13

STUDY TIPS: Know equation on pg 205, understand diagram on pg 208, know the octet rule and exception. Know table on page 212. Practice more problems in the book at the end of the chapter to master the things we cover tonight.

1. Describe the difference between a covelant bond and an ionic bond.

2. Draw the Lewis dot symbol for each of the following atoms: (a) boron (b) fluorine (c) selenium (d) indium

3. Use Lewis dot symbols to explain why chlorine bonds with only one Hydrogen atom.

4. Define the term lone pair.

5. How many electrons are shared between two atoms in (a) a single covelant bond, (b) a double covelant bond, (c) a triple covelant bond?

6. How does the bond energy of a double bond compare to that of two single bonds between the same elements? How does this relationship explain the types of reactions that double bonds undergo?

7. When two atoms with different electronegativities form a covelant bond, what does the electron distribution in the bond look like? 8. Based on the positions in the periodic table of the following elements, predict whether bonding between the two will be primarily ionic or covelant. Justify your answers. (a) Ca and Cl (b) P and O (c) Br and I

9. In each group of 3 bonds, which bond is likely to be the most polar? The least polar? (a) C—H, O—H, S—H, (b) C—Cl, Cl—Cl, H-Cl

10. Draw the Lewis structure for each of the following molecules: (a) CO (b) H2S (c) SF6

11. In the context of Lewis structures, what is resonance?

- - 12. Draw resonance structures for (a) NO2 (b) HCO2

13. Which species listed below has a Lewis structure with only one lone pair of electrons? F2, 2- CO3 , CH4, PH3