REACTIONS OF HYDROCARBONS

2. Substitution (with halides)

alkane + halogen haloalkane +hydrogen halide

CH4 + Cl2 CH3Cl + HCl

CH3Cl + Cl2 CH2Cl2 + HCl

1. Combustion (Extreme Oxidation)

Alkane + O2 CO2 + H2O

ALKANES

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Incomplete combustion

Alkane + O2 CO + H2 O

ALKENES

1. Addition Reactions (breaking of the double bond)

A) Halogenation (adding halides)

alkene + halogen haloalkane

B) Hydrogenation (adding hydrogen)

alkene + hydrogen alkane

CH2=CH2 + H2 CH3CH3

PtPtPtPt

H2C CH2 + Cl2 C C

H

Cl

H

Cl

H

HCCl4

C) Hydrohalogenation (adding hydrogen halides)

alkene + hydrogen halide haloalkane

Hydrohalogenation and hydration follow Markovnikov’s Rule which states that the hydrogen is added to the carbon with the most hydrogen atoms originally bonded to it.

H2C CHCH3 + HCl C C

H

Cl

C

H

H

H

H

H

H

D) Hydration (adding water)alkene + water alcohol

H2C CHCH3 + H2O C C

H

OH

C

H

H

H

H

H

H

2. Combustion (extreme oxidation)

Alkene + O2 CO2 + H2O

3. Polymerization (forming long chains from small subunits)

C C

H

H H

H

n C C*

H

H

H

H

*

n

*Polymerization will be addressed later

ALKYNES1. Addition Reactions (breaking of the multiple bond)

A) Halogenation (adding halides)

alkyne + 2 halogens haloalkane

alkyne + 1 halogen haloalkene

CH CH + 2 Br2 C C

Br

H

Br Br

Br

H

CH CH + 2 Br2 C C

Br

H

Br Br

Br

H

B) Hydrogenation (adding hydrogen) alkyne + 2 hydrogen alkane

C) Hydrohalogenation (adding hydrogen halides)

alkyne + 2 hydrogen halides haloalkane

CH CH + 2 HCl C C

H

H

H Cl

Cl

H

Reactions of Aromatics1. Substitution

A) With Halogens

benzene + halogen halobenzene + hydrogen halide

Note: Due to reduced reactivity of the ring bonds compared with double bonds, aromatics due not undergo addition reactions under normal conditions.

Br

+ Br2

FeBr3

+ HBr

2. With Alkyl Halides ( not mentioned in textbook)

benzene + alkyl halide alkyl benzene + hydrogen halide

3. With Nitric Acid ( not mentioned in textbook)

benzene + nitric acid nitrobenzene + water

CH3CH2

+ CH3CH2ClAlCl3

+ HCl

NO2

+ HNO3 (aq)H2SO4

+ H2O

nitrobenzene