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

2. Unsaturated hydrocarbons Unsaturated hydrocarbons: organic compounds containing one or more double or triple bonds – can add more H by breaking the bond

3. Alkenes hydrocarbons Another homologous series of hydrocarbons one unsaturated Each member contains at least one double covalent bond between C atoms  So alkenes are unsaturated General formula = C n H 2n

4. Properties of Alkenes Nonpolar – low solubility in H 2 O fairly low melting and low boiling points More reactive than alkanes : – double bond is site of reactivity

5. 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

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

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

8. 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

9. 3 methyl, 1-butene 1 2 3 4

10. Alkynes Homologous series of unsaturated hydrocarbons Each member contains at least one C≡C bond General formula = C n H 2n-2

11. Properties of Alkynes Nonpolar – low solubility in H 2 O fairly low melting and low boiling points More reactive than alkenes : – triple bond is site of reactivity

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

13. 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

14. 3 Homologous Series of HC ’ s -yneC n H 2n-2 Alkynes -eneC n H 2n Alkenes -aneC n H 2n+2 Alkanes EndingGeneral FormulaName of Series

15. A.C 2 H 2 B.C 2 H 4 C.C 6 H 6 D.C 6 H 14 Which compound belongs to the alkene series? Correct answer = B Alkenes follow the format C n H 2n A & C are C n H n, D is C n H 2n+2

16. A.C 2 H 2, C 2 H 4, C 2 H 6 B.C 2 H 4, C 3 H 4, C 4 H 8 C.C 2 H 4, C 2 H 6, C 3 H 6 D.C 2 H 4, C 3 H 6, C 4 H 8 In which group could the hydrocarbons all belong to the same homologous series? Correct answer = D Members of homologous series all have same relationship between atoms Every compound in set D fits the formula C n H 2n

17. A.Ethene B.Ethyne C.Propene D.Propane Which of the following is a saturated hydrocarbon? Correct answer = D all alkanes are saturated