III. Isomers - compounds with the same molecularformula that have different structural arrangements.

A. The simplest alkane that can have isomers isbutane, with a molecular formula of C4H10:

structuralformula

ball and stick

normal-butaneaka n-butane

isobutaneaka i-butane

Isobutane as a gas for refrigeration systems, especially in domestic refrigerators and freezers, and as a propellant in aerosol sprays. When used as a refrigerant or a propellant, isobutane is also known as R-600a. Some portable camp stoves use a mixture of isobutane with propane, usually 80:20. Isobutane is used as a feedstock in the petrochemical industry, for

Butane gas is sold bottled as a fuel for cooking and camping. When blended with propane and other hydrocarbons, it is referred to commercially as LPG. It is also used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters and as a propellant in aerosol sprays such as deodorants.

n-butanei-butane

n-butane:b.p. = -0.5 0C

i-butane:b.p. = -12 0C

B. Isomers have different chemical and physical properties.

Ex. Which isomer of butane has a higher boiling point?

C. As the number of carbon atoms increases,the number of possible isomers increases. This is one reason why there are so many organiccompounds.

Ex. butane (C4H10) has 2 isomersoctane (C8H18) has 18 isomersdecane (C10H22) has 75 isomers

ibuprofen is made of 2 isomers:

What do thesehave in

common?

V. Functional Groups Many new organic compounds are formed when atoms other than C and H replace H in a hydrocarbon. These atoms or groups of atoms are called functional groups. The unchanged part of the remaining hydrocarbon is shown with an R:

R

rest of the hydrocarbon functional group goes here

Each type of functional group produces a uniqueclass (type) of compound and gives the compound distinct chemical and physical properties.

bond

A. Halides Functional group: F, Cl, Br, I

When the halogens (F, Cl, Br, I) replace a H atom in a hydrocarbon, the compound is called an organic halide or halocarbon.

Ex. Take methane CH4 and replace an H with a Cl

It was used as a refrigerant and is now used to

make polymers.

formula:methane

becomes

Cl

CH3Cl

PVC = polyvinylchlorides:

ethylene + chlorene = chloroethylene

PVC products

9000 shellfishto produce1 gram ofTyrolian purple

Rubens: The discovery ofTyrolian purple

PCBs

Uses:plasticisers in paints and cementscasting agentsfire retardant fabric treatments and heat stabilizing additives for PVC electrical insulationadhesivespaints and water-proofingrailway sleepers

capacitorsinsulating fluids in transformersvacuum pump fluidshydraulic fluids

Between approximately 1947 and 1977, GE released up to 1,300,000 pounds (590,000 kg) of PCBs into the Hudson River

Polychlorinated biphenyl

TOXIC

A brominated flame retardant. It consists of twelve carbon, eighteen hydrogen, and six bromine atoms tied to the ring. Its primary application is in polystyrene foam that is used as thermal insulation in the building industry. Other uses are upholstered furniture, automobile interior textiles, car cushions and insulation blocks in trucks, packaging material, video cassette recorder housing and electric and electronic equipment.

1,2,5,6,9,10-Hexabromocyclododecane

TOXI

C

Brominated Fire Retandants:

TOXIC

Ex. Chloroform. Used to be used as an anesthetic,but is toxic. Now used as a solvent and to produce dyes and pesticides. Replace 3 H’s with Cl’s.

methane

becomes

Cl|

Cl |Cl

H— C—

Ex. CFCs (chlorofluorocarbons) cause the ozone layer to be destroyed.

methane

Freon-22

CFCs

DDT:

dichlorodiphenyltrichloroethane

TOXIC

C

C

Polytetrafluoroethylene: Teflon

TOXIC

B. Alcohols R—____Functional Group = ___________ group = OH

The OH group makes alcohols polar. Alcohols dissolve in water because H2O is polar:

Alcohol names all end in –___.

Start with:

HO

H

OH

Replace anH with an-___ group:

Ex:

End up with:

H

H

H

C H

____________

H

H

H

C

__________ ormethyl alcohol

OH

hydroxyl

ol

+-

+

-

+

methane

OHOH

CH3OH

Ex. __________ (ethyl alcohol) = drug, solvent, fuel

H

H

H

C

H

H

C H

___________ ________ or ethyl alcohol

Replace anH with an-OH group:

H

H

H

C

H

H

C

Ex. __________ alcohol (rubbing alcohol)

H

H

H

C

H

H

C H

___________ _________ or Isopropyl alcohol

Replace a_________H with an-OH group:

H

H

C H

H

H

C

H

C H

H

H

C

ethanol

ethane

OH

CH3CH2OH

isopropyl

propane

middle

OH

CH3CHOHCH3

ethylene glycol

Ethylene glycol is widely used as an automotive antifreeze and a precursor to polymers. In its pure form, it is an odorless, colorless, syrupy, sweet-tasting liquid. Ethylene glycol is toxic, and ingestion can result in death.

OH

OH

H

H

C

H

C H

Glycerin (glycerol):--> clear, sweet tasting, oily liquid--> used to keep dried fruits and pastry fillings moist, in toothpaste, hand creams, eye and ear drops,suppositories (for laxatives, eg), and as an antifreeze

H2SO4 for drying

aka nitroglycerin(dynamite)Also:

glycerin + nitric acid --> glycerol trinitrate