Chemistry Exam 1; Hydrocarbons-Alkanes, Alkenes, Alkynes, Aromatics

Alkene's have ______ bonds.

double

Alkene's end in ______.

-ene

Alkenes are a _______ hydrocarbon.

unsaturated

Unsaturated Hydrocarbons

Chains of hydrogen and carbon without all single bonds.

Alkene formula

CnH(2n-2)

Physical Properties of Alkenes

1. Insoluble in water

2. Soluble in nonpolar solvents

3. Lower density than water

4. Lower melting point than Alkanes

The two common alkenes;

Propylene(propene) and Ethylene(ethene)

Ethylene (ethene)

C2H4, Ch2=Ch2.

Ripens fruit faster.

Propylene(propene)

C3H6, CH2=CH-CH3.

Two naturally occurring alkenes;

Pheromones, and Terpenes

Purpose of Pheromones

Gives off signals by insects/animals during mating season.

Terpenes

A hydrocarbon chain with two or more 5-carbon isoprene units.

Example of Terpenes

Betacarotene; found in carrots.

Tertbutyl

l

CH3--C--CH3

l

CH3

Isopropyl

l

CH--CH3

l

CH3

Saturated hydrocarbons

All single bonds

Unsaturated hydrocarbons

1 or more multiple bonds

Physical Properties of Hydrocarbons

1. Not soluble in water

2. Less dense than water

3. The larger the structure the higher the boiling point, because there are more bonds to break.

Combustion

The products of this reaction are always CO2 and H2O.

Two types of reactions for alkanes

1. Combustion

2. Halogenation

Halogenation is an example of a ___________ reaction. This is the only type of _________ reaction that alkanes can do.

Substitution

The diatomics of a halogenation reaction will be;

F2, Br2, Cl2, I2.

In a _______ reaction I'm always adding a _________ to form a halogenated (cyclo)alkane. To name them I'm using the element as a prefix- for example 'Chloro.'

halogenation; halogen

Methane is the simplest __________.

alkane

Alkanes end in _____.

-ane

Steps of naming alkanes

Find the longest carbon chain

# the carbon chain

name alkyl groups

What? Where? How many?

Alphabetize

#,# #-word

Alkene + _________ = ___________

This is a __________ reaction.

hydrogen; alkane

hydrogenation

What is the smallest cycloalkane?

Cyclopropane

Positional Isomers

Same carbon arrangement but hydrogens are arranged differently because of the placement of the double bond.

Skeletal Isomers

Cis and trans isomer

Cis isomer

Trans isomer

Symmetrical Addition

Hydrogenation and Halogenation

Unsymmetrical Addition

Hydrohalogenation and Hydration

Rules of naming Alkenes

End in -ene

Largest chain with double bond

# closest to the double bond

Give position of the double bond

If multiple double bonds; -diene, -triene, -tetrene

Cyclo- == bond is always between C1 and C2, but is not written.

Cyclo- multiple double bonds; lowest number possible

Functional Group

Part of the molecule where the reactivity occurs

Benzene

The simplest aromatic hydrocarbon.

Aromatic Hydrocarbons

Unsaturated cyclic hydrocarbon which does not readily undergo addition reactions.

Benzene has______ bonds. Which are...?

Delocalized bonds; Covalent bond in which electrons are shared among more than 2 atoms.

Toluene and it's IUPAC

methylbenzene

Xylene

Common name for isomers of dimethylbenzene.

Ortho-xylene

On carbons 1 and 2

Meta-xylene

On carbons 1 and 3

Para-xylene

On carbons 1 and 4

Napthalene

Bad smelling mothball

Anthracene

Phenanthrene

________ __________ are the only hydrocarbons that can undergo alkylation.

Aromatic Hydrocarbons

AlCl3 is a catalyst of this type of reaction.

Alkylation