1. Chemistry 22.2

2. Unsaturated Hydrocarbons
Roach traps are baited with pheromones, which roaches produce to attract mates. The structure of many pheromones is based on unsaturated hydrocarbons. You will study two types of unsaturated hydrocarbons—alkenes and alkynes.

3. Alkenes
Alkenes
What are the structural characteristics of alkenes?

4. Alkenes
At least one carbon-carbon bond in an alkene is a double covalent bond. Other bonds may be single carbon-carbon bonds and carbon-hydrogen bonds.

5. Alkenes
Organic compounds that contain the maximum number of hydrogen atoms per carbon atom are called saturated compounds.
Compounds that contain double or triple carbon-carbon bonds are called unsaturated compounds.

6. Alkenes
Alkenes are hydrocarbons that contain one or more carbon-carbon double covalent bonds.

7. Alkenes
Because rotation is restricted around the double bond, atoms in ethene lie in one plane.
Ethene
Because rotation is restricted around the double bond, atoms in ethene lie in one plane. Calculating What is the ratio of hydrogen to carbon in ethene?

8. Alkynes
Alkynes
What are the structural characteristics of alkynes?

9. Alkynes
At least one carbon-carbon bond in an alkyne is a triple covalent bond. Other bonds may be single or double carbon- carbon bonds and single carbon- hydrogen bonds.

10. Alkynes
Hydrocarbons that contain one or more carbon-carbon triple covalent bonds are called alkynes.
Straight-chain and branched-chain alkanes, alkenes, and alkynes are aliphatic hydrocarbons.

11. Alkynes
The triple bond restricts rotation in an ethyne molecule, which has a linear shape.
The triple bond restricts rotation in an ethyne molecule, which has a linear shape. Calculating What is the ratio of hydrogen to carbon in ethyne?

12. Alkenes

13. 22.2 Section Quiz.
22.2.

14. 22.2 Section Quiz.
1. Alkenes and alkynes are called unsaturated compounds because they contain
single bonds only.
double or triple bonds.
oxygen atoms.
hydrogen atoms.

15. 22.2 Section Quiz.
2. What is the correct name for a compound with a C-C-C=C-C carbon skeleton?
3-pentyne
2-pentene
3-pentene
4-pentene

16. 22.2 Section Quiz.
3. Which of the following substances is an alkyne?
C6H12
C2H4
C2H2
C4H8

17. END OF SHOW