1. Molecules in Two Dimensions Structural Formulas

2. Chem Catalyst ✤ You will smell samples of three molecules: Vial F: Ethyl pentanoate:C 7 H 14 O 2 Vial G: Butyric acidC 4 H 8 O 2 Vial H: Ethyl acetateC 4 H 8 O 2 ✤ Predict how their smells might compare. Give evidence for your predictions.

3. Team Work ✤ Print and tape instructions on the left page. ✤ Draw the table on the right page. Fill in your predictions. Vial Chemical Name Molecular Formula Predicted Smell Actual Smell F ethyl pentanoate C 7 H 14 O 2 Gbutyric acidC4H8O2C4H8O2 Hethyl acetateC4H8O2C4H8O2

4. Results ✤ Most students agreed on the following actual smells when they opened the vials: ✤ Vial F: sweet ✤ Vial G: putrid ✤ Vial H: sweet ✤ Use this data to complete the table. Then go on and complete Part 2 of the activity (see instructions, then come back to notes on the next slide).

5. Notes ✤ Structural Formula: A drawing or diagram of a molecule that shows how the atoms in the molecule are bonded (covalent). ✤ Molecules with identical formulas can have different structures, giving them different properties, like smell. ✤ Isomers: Molecules with the same molecular formula but different structural formulas. ✤ Merely rotating the molecule or bonds does not change the structural formula or properties of the molecule (1-propanol).

6. Homework ✤ Lesson 2: Molecules in Two Dimensions ✤ Pages 149-153. ✤ Questions #1-6.