Pentene

CH3CH2CH2CH=CH2

Alkenes, alkynes

Can be

Hydrocarbons

Saturated(Single Bonds)

Can beUnsaturated

(Double Bond)

EtheneCH2=CH2

Alkanes

Cycloalkanes

Saturated carbonSaturated carbon

ByBy

Entrancei.comEntrancei.com

Saturated and Saturated and Unsaturated?Unsaturated?

HC

H

H

CH

H

H

C

H

H

C

H

H

CH2

CH2 CH2

CH2

C

CC

H H

H

HH

H

HC

H

C

H

H

C

H

H

CH2CHCH3

Saturated

Saturated

Saturated

Unsaturated Unsaturat

ed

Addition of BromineAddition of Bromine

HC

H

CH

H

C

H

H

BrBrDouble Bonds

Undergo

Addition Reactions

In Addition ReactionsThe double bond

Breaks and bromine atomsare added to both sides

of the double bond in anti addition

Addition of Hydrogen Addition of Hydrogen (H(H22))

HC

H

CH

H

C

H

H

HHThe double bond

Breaks and Hydrogen atomsare added to both sides

of the double bond

Propene + HydrogenPropane

Alkenes into AlkanesAlkenes into Alkanes

CCCCC

H HH H

HH

CH

H

H H

H

H

H H

Hexene + HydrogenC6H12 H2+

Hexane

C6H14

N

1.

CCCCCC

H HH H

HH

HHHHHH

HH

Alkenes into AlkanesAlkenes into Alkanes

CCCCCCC

H HH HH H

HH

HHHHH

CH

H

H

HCCCCCCCC

H H H HH HH H

HH

HHHHHHHH H

Octene + Hydrogen Octane

C8H16 H2+ C8H18

2.

Saturated? No Saturated? No double bonddouble bond

C2H6

C4H10

C20H42

C10H20

C15H30

C8H18C7H14

C60H122

C11H22

?

??

?

C4H8?

C4H8?

Alkenes and CycloalkanesAlkenes and CycloalkanesIsomers from different Homologous Series

CnH2n

Alkenes

Cyclo-alkanes

Unsaturated

Saturated

C4H8

C4H8

C4H8

CH2

CH2 CH2

CH2

HC

H

H

C

H

C

H

H

C

H

H

Butene

Cyclobutane

Unsaturated Saturated

Reacts withBromine

UnreactiveNo Reaction with

Bromine

CC55HH1010

►Describe how you could find out, which Describe how you could find out, which test tube contained pentene and which test tube contained pentene and which test tube contained cyclopentanetest tube contained cyclopentane

A B

Pentene

Cyclopentane

►Only Tube A decolourised bromine water.Only Tube A decolourised bromine water.

Bromine WaterBromine Water

► Alkenes react with Bromine water.Alkenes react with Bromine water.► The bromine water changes from brown to The bromine water changes from brown to

clear.this is a test for alkenesclear.this is a test for alkenes► Tube A must contain PenteneTube A must contain Pentene

Alkenes

Bromine Water

Alkane