1. Topic: Naming Alkenes & Alkynes (unsaturated hydrocarbons) Do Now: Name the following

2. Naming Alkenes 1.Count longest carbon chain – prefix tells # of C ’ s in longest chain and add ‘ene’ 1 st member is C 2 H 4: ethene H H H H C=C H H

3. 2. If more than 4 Carbons – give 1 st carbon in double bond the lowest possible number when numbering the chain ] 1-butene 2-butene

4. If 2 double bonds = diene 1,3 pentadiene

5. Naming Branched-Chain Alkenes 1 st carbon in Double bond gets lowest number Then name branches based on numbers assigned Branch name and number come first when naming Chain + ene come at the end – Example: 2-methyl 3-Nonene

6. 3 methyl, 1-butene 1 2 3 4

7. Naming Alkynes Same as alkene just add ‘yne’ to the end instead

8. H–C  C–HC 2 H 2 ethyne CHCH H H–C  C–C–H H H H H–C  C–C–C–H H H H–C–C  C–C–H H H C3H4C3H4 propyne CHCCH 3 C4H6C4H6 1-butyne CHCCH 2 CH 3 C4H6C4H6 2-butyne CH 3 CCCH 3