Lewis Structures with Resonance and Formal Charges

Draw the Lewis structures for the following molecules.

H₂O, CO₂, N₂

Share a whiteboard with one other classmate at your table and show your drawings to Mrs. Zaepfel. You'll reference these structures for the next few questions, so don't erase them.

The password is: ​ (a)   ​ (b)  

• tungsten
• polonium
• bismuth
• tin
• silver
• oxygen
• hydrogen
• strontium
• cobalt
• arsenic

In the previous question, you drew three different kinds of bonds. Define each of these kinds of bonds as best you can.

a) single bond:

• A bond formed by sharing one pair of electrons between two atoms, for a total of 2 bonding electrons

• A bond formed by sharing two pairs of electrons between two atoms, for a total of 4 bonding electrons

• A bond formed by sharing three pairs of electrons between two atoms, for a total of 6 bonding electrons

• A bond involving the transfer of electrons from one atom to another

b) double bond:

• A bond formed by sharing one pair of electrons between two atoms, for a total of 2 bonding electrons

• A bond formed by sharing two pairs of electrons between two atoms, for a total of 4 bonding electrons

• A bond formed by sharing three pairs of electrons between two atoms, for a total of 6 bonding electrons

• A bond involving the transfer of electrons from one atom to another

b) triple bond:

• A bond formed by sharing one pair of electrons between two atoms, for a total of 2 bonding electrons

• A bond formed by sharing two pairs of electrons between two atoms, for a total of 4 bonding electrons

• A bond formed by sharing three pairs of electrons between two atoms, for a total of 6 bonding electrons

• A bond involving the transfer of electrons from one atom to another

In general, which kind of bond do you think would be harder to break—a single, double or triple bond?

• Single bond

• Double bond

• Triple bond

After looking at the data in this table, is your answer to the previous question consistent with the data in the table?

• Yes, because a triple bond requires more energy to break.

• No, because a triple bond requires the least amount of energy to break.

What is the relationship between bond order and single, double, and triple bonds?

• The number of bonds

• Bond order decreases from single to triple bonds

• Bond order stays constant for single, double, and triple bonds

• Bond order is unrelated to the type of bond

What relationship exists between bond length and bond energy?

• Directly proportional

  As bond length shortens, bond energy decreases.

• Inversely proportional

  As bond length shortens, bond energy increases.

• No relationship

• Depends on the molecule

Which bonds are shortest—single, double or triple?

• Single bonds

• Double bonds

• Triple bonds

Based on the Lewis structure, what is the bond order for each C—C bond? Label your predictions (bond order of 1 or 2) on the structure next to each bond.