Chemistry and Society Exam #2 Study Guide
Chapter 9: Organic Chemistry
Organic chemistry – is defined as the chemistry of carbon containing compounds.
Some compounds come from livings things while others do not.
Friedrich Wöhler ▯father of organic chemistry. Discovered synthetic urea in his
9.1: Aliphatic Hydrocarbons
• Aliphatic compounds – nonaromatic compounds
• Hydrocarbon – organic compounds that contains only hydrogen and carbon.
• Alkanes – hydrocarbons that contain only single bonds.
o Are called saturated hydrocarbons – because each carbon atom is saturated
with hydrogen atoms.
o Formula: C nH 2n+2
• Condensed Structural Formulas show how many hydrogen atoms are attached to
each carbon atom without showing the bond to each hydrogen atom.
o Ethane = CH 3CH 3; Propane = CH3CH 2CH 3
compounds that have the same molecular formula (Butane: C4H10; Isobutane:
C4H10) but different structural formulas.
• Properties of Alkanes:
o The densities of liquid and solid alkanes are less than that of water.
o Alkanes are nonpolar molecules and are insoluble in water.
o They dissolve many organic substances of low polarity such as fats, oils and
o They burn, producing a lot of heat; they mainly serve as fuels. o They can cause chemical pneumonia and can be harmful if swallowed.
o Heavier liquid alkanes act as skin softeners (emollients) and laxatives.
• Cyclic Hydrocarbons: Rings and Things
o Cyclic hydrocarbon – carbon atoms can also connect to form closed rings.
Cycloalkanes – cyclic hydrocarbons containing only single bonds
Cyclopropane is a quick acting anesthetic (causes general or local
insensibility) without side effects. BUT it is extremely flammable and
o Formula: C nH 2n
• Unsaturated Hydrocarbons: Alkenes and Alkynes
o Alkene – is a hydrocarbon that contains one or more carbontocarbon double
Formula for 1 double bond: C nH 2n
Ethylene/Ethene (CH 2CH 2)– most important organic chemical
(polyethylene and ethylene glycol ▯antifreeze)
o Alkyne – is a hydrocarbon that contains one or more carbontocarbon triple
Formula for 1 triple bond: CnH 2n2
Acetylene/Ethyne (CHCH ) –used in oxyacetylene torches for cutting
and welding metals.
o Unsaturated Hydrocarbons – hydrocarbons that can have more hydrogen
atoms added to it. They can undergo addition reactions.
• Properties of Alkenes and Alkynes
o Are insoluble and float on water
o Can undergo addition reactions in which all the atoms of the reactants are
incorporated into a single product.
o Add to each other to form polymers
9.2 Aromatic Compounds: Benzene and its Relatives
• Benzene (CHCHCHCHCHCH) [C 6H 6] – discovered by Michael Faraday but
Friedrich Kekule deduced the structure of benzene in a ring shape. Benzene and
similar compounds are called aromatic hydrocarbons because of their strong
o This is how the benzene ring is represented
o Benzenelike compounds float on water, are used mainly as
solvents and fuels. o Toluene/Methylbenzene [C 6H 5CH 3]
9.3 Chlorinated Hydrocarbons: Many Uses,
• Chlorinated Hydrocarbons – organic compounds from hydrocarbons by
replacing one or more hydrogen atoms with a chlorine atom.
o Most are slightly polar and do not dissolve in water. They dissolve in fats,
oils, greases and other substances of low polarity.
o Make good degreasing and dry cleaning solvents; they remove grease and
oily stains from fabrics.
o Dichloromethane/methylene chloride (CH2Cl2) is used as a solvent and
o Trichloromethane/chloroform (CHCl3) is also a solvent and at one was
used as an anesthetic long ago. It is now considered hazardous.
o Carbon Tetrachloride (CCl4) can be used in dry cleaning and fire
extinguishers. It can be deadly when used with water because the toxic gas
phosgene forms; causes liver damage as do other chlorinated
o Chloromethane/methyl chloride (CH3Cl)
• Chlorofluorocarbons and Fluorocarbons
o Compounds containing both fluorine and chlorine (CFCs)
o Have been used as the dispersing gas in aerosol cans for making foamed
plastics, and as refrigerants.
o React with ozone to deplete the Earth’s layer of ozone.
o Some of them are used to carry oxygen in blood. O2 can be very soluble in
9.4 The Functional Group
• Functional group – atoms or groups of atoms attached to hydrocarbon skeletons
give the compounds characteristic chemical and physical properties.
• Alkyl group – is derived from an alkane by removing a hydrogen atom. Methyl
CH3— and Ethyl CH3CH2—
• O,N,S are sometimes called “heteroatoms”, which simply means noncarbon
atoms in this context 9.5 Alcohols, Phenols and Ethers
• Alcohol – when a hydroxyl group (OH) is substituted for any hydrogen atom in
• Proper name – remove the –e from the corresponding alkane and replace with –ol
o Methanol/methyl alcohol (CH3OH) is sometimes called
“woodalcohol” (from fermentation process). It is an important solvent and
automotive fuel additive and possible fuel replacement. It is toxic and can
cause blindness, among other health problems.
o Ethanol/ ethyl alcohol (CH3CH2OH) is also known as grain alcohol.
It is the alcohol of alcoholic beverages. It is also an additive to automotive
fuel and is being considered as a gasoline replacement (Chapt. 15). Made
by grain fermentation by yeast (breakdown of sugars or starches). By
adding H+ makes an acidcatalyzed hydration reaction. If ethanol is
made this way it is “denatured” to prevent consumption.
• Multifunctional Alcohols
o Ethylene glycol (CH2OHCH2OH) – High boiling, antifreeze, sweet but
toxic! It is oxidized in the liver to oxalic acid, the solid calcium salt of
which can damage the liver (see next slide). Can even lead to death.
o Propylene glycol is a safer antifreeze; liver enzymes do not act upon it,
used in food products
o Glycerin (Glycerol) – sweetener, moisturizer, can be converted to
nitroglycerin, which is an explosive AND a heart medicine!
o When a hydroxyl group is attached to a benzene ring. Unlike alcohols,
phenol is a weak acid and it is quite poisonous compared to most simple
o Phenol is an effective antiseptic (as long ago as 1867!) – however causes
skin burns. C