1. Formulas, Structures, Isomers, and Boiling Points Chemistry

2. Chemical Molecular Formula Structural Formula Condensed Formula MethaneCH 4 Ethanoic Acid C2H4O2C2H4O2 CH 3 COOH GlucoseC 6 H 12 O 6 CHO(CHOH) 4 CH 2 OH

3. Why Molecular Formulas Do Not Always Work Draw C 4 H 10 Isomer- Same molecular formula, different arrangement of atoms Constitutional isomers Isomers have different physical and chemical properties

4. See if you can figure this out… Draw & name all isomers of C 5 H 12 (3 total!) Pentane 2-methylbutane 2,2-dimethylpropane

5. See if you can figure this out… Draw & name all isomers of C 6 H 14 (5 Total!) Hexane 2-methylpentane 3-methylpentane 2,3-dimethylbutane 2,2-dimethylbutane

6. Cis/Trans Isomers Stereoisomers Molecules cannot rotate around a double bond Cis:  Similar groups on the same side Trans:  Similar groups on the opposite side Trans-2-pentene Cis-2-pentene

7. Hydrogenation of Triglycerides Food industry hydrogenates oils to control the texture Leads to creation of trans-fats Linked to LDL cholesterol build-up in the arteries

8. Boiling Points Boiling Points increase with increasing M r (molar mass)  Van der Waals Forces increase Branching decreases Van der Waals forces, and therefore decreases boiling point AlkaneB.P. (ºC) Methane, CH 4 -164 Ethane, C 2 H 6 -89 Propane, C 3 H 8 -42 Butane, C 4 H 10 -0.5 Pentane, C 5 H 12 36 Hexane, C 6 H 14 69 Heptane, C 7 H 16 98 Octane, C 8 H 18 125

9. Put the Following in order from Lowest B.P. to Highest B.P. 1. 2. 3. 4. 5.