2 7 Physical Properties of Alkenes 1 Nonpolar

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2. 7 Physical Properties of Alkenes 1

2. 7 Physical Properties of Alkenes 1

• • Nonpolar Insoluble in water Soluble in nonpolar organic solvents. Less dense

• • Nonpolar Insoluble in water Soluble in nonpolar organic solvents. Less dense than water: they float on water. PHYSICAL PROPERTIES LIKE ALKANES 2

2. 8 Chemical Properties of Alkenes 3

2. 8 Chemical Properties of Alkenes 3

REACTIONS OF ALKENES ØCombustion ØAddition reactions : ühydrogenation ühalogenation ühydrohalogenation ühydration (addition of water)

REACTIONS OF ALKENES ØCombustion ØAddition reactions : ühydrogenation ühalogenation ühydrohalogenation ühydration (addition of water) 4

• Addition reactions: A substance adds to the multiple bond of an unsaturated

• Addition reactions: A substance adds to the multiple bond of an unsaturated reactant to yield a saturated product that has only single bonds. 5

In an addition reaction the atoms of the reactant molecule attach to the carbon

In an addition reaction the atoms of the reactant molecule attach to the carbon atoms originally joined by a double bond. The double bond becomes a single bond. 6

1. Symmetrical Addition Reactions: In which identical atoms are added to each carbon of

1. Symmetrical Addition Reactions: In which identical atoms are added to each carbon of the double bond. 2. Unsymmetrical Addition Reactions: In which different groups are added to each carbon of the double bond. For example, hydration or hydrohalogenation. 7

1. Symmetrical addition reactions HYDROGENATION: The addition of H-H to C=C HALOGENATION: The addition

1. Symmetrical addition reactions HYDROGENATION: The addition of H-H to C=C HALOGENATION: The addition of Cl 2 or Br 2 to C=C 8

HYDROGENATION catalyst = Pt, Pd, Ni Hydrogenation is the addition of hydrogen (H 2)

HYDROGENATION catalyst = Pt, Pd, Ni Hydrogenation is the addition of hydrogen (H 2) to a functional group. It requires a catalyst (cat) NO REACTION WITH C=C IN AROMATIC RINGS! 9

HALOGENATION Addition of Cl 2 and Br 2 to alkenes: • Alkenes react with

HALOGENATION Addition of Cl 2 and Br 2 to alkenes: • Alkenes react with the halogens Br 2 and Cl 2 to give the 1, 2 -dihaloalkanes. D: Chem 11moviesaddition. mov 10

Bromine in water is a reddish brown solution. Br 2 Bromine adds to the

Bromine in water is a reddish brown solution. Br 2 Bromine adds to the alkene to form colorless dibromo compounds. 11

2. Un. Symmetrical addition reactions HYDROHALOGENATION : The addition of H-Cl, HBr or H-I

2. Un. Symmetrical addition reactions HYDROHALOGENATION : The addition of H-Cl, HBr or H-I to C=C Hydration: The addition of H 2 O to C=C 12

HYDROHALOGENATION Addition of HCl and HBr to alkenes: • Alkenes react with hydrogen bromide

HYDROHALOGENATION Addition of HCl and HBr to alkenes: • Alkenes react with hydrogen bromide and hydrogen chloride to give alkyl bromide or alkyl chloride products. 13

• Markovnikov rule: In the addition of HX to an alkene, the H

• Markovnikov rule: In the addition of HX to an alkene, the H becomes attached to the carbon that already has the more H’s, and X becomes attached to the carbon that has fewer H’s. D: Chem 11moviesHCLadddition. mov 14

HYDRATION Addition of water (H-OH) to alkenes An alcohol is produced on treatment of

HYDRATION Addition of water (H-OH) to alkenes An alcohol is produced on treatment of the alkene with water in the presence of a strong acid catalyst, such as H 2 SO 4. Markovnikov’s rule applies. 15

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Alkenes and Alkynes Alkenes Alkenes are unsaturated hydrocarbonsAlkenes and Alkynes Alkenes Alkenes are unsaturated hydrocarbons
Nonpolar Covalent Bonds Electrons Produces nonpolar molecules suchNonpolar Covalent Bonds Electrons Produces nonpolar molecules such
Polar or Nonpolar CH 4 Nonpolar Polar orPolar or Nonpolar CH 4 Nonpolar Polar or
Physical and Chemical Properties Physical Properties Are propertiesPhysical and Chemical Properties Physical Properties Are properties
Properties of Matter Physical Properties Chemical Properties PhysicalProperties of Matter Physical Properties Chemical Properties Physical
Physical and Chemical Properties Physical Properties Physical propertyPhysical and Chemical Properties Physical Properties Physical property
Physical Chemical Properties NOTES 1 Physical Properties PhysicalPhysical Chemical Properties NOTES 1 Physical Properties Physical
Chemical and Physical Properties Physical properties A physicalChemical and Physical Properties Physical properties A physical
Physical Chemical Properties Changes Physical Properties A physicalPhysical Chemical Properties Changes Physical Properties A physical
Physical Properties 2 2 Physical Properties A physicalPhysical Properties 2 2 Physical Properties A physical
ALKENES AND ALKYNES Alkenes contain one or moreALKENES AND ALKYNES Alkenes contain one or more
Nomenclature of Alkenes 1 Nomenclature of Alkenes FigureNomenclature of Alkenes 1 Nomenclature of Alkenes Figure
THE CHEMISTRY OF ALKENES CONTENTS Structure of alkenesTHE CHEMISTRY OF ALKENES CONTENTS Structure of alkenes
Drill Name the following Alkenes Alkenes Hydrocarbons withDrill Name the following Alkenes Alkenes Hydrocarbons with
p 251 Alkenes Alkynes I Prepapration of alkenesp 251 Alkenes Alkynes I Prepapration of alkenes