Carbon and Organic
Compounds
Organic vs. Inorganic
• Organic compounds contain carbon that
is covalently bonded to non-metals
Comparison of Properties of Organic
and Inorganic Compounds
Property
Solubility in inorganic
solvent (water)
Solubility in organic
solvent (toluene)
Conductivity
Flammability
Volatility
Melting Point
Boiling Point
Organic
Inorganic
Comparison of Properties of Organic
and Inorganic Compounds
Property
Organic
Inorganic
Solubility in inorganic
solvent (water)
Generally not soluble
soluble
Solubility in organic
solvent (toluene)
Generally soluble
Not soluble
Conductivity
Non-conductive
conductive
Flammability
Generally flammable
Not flammable
Volatility
More volatile
Not volatile
Melting Point
Low
High
Boiling Point
Low
High
The position of carbon in the periodic table.
Carbon’s Key Properties
• Has a mid-range electronegativity value
so it forms covalent bonds and shares
electrons
• Can form a maximum of four bonds
• Can form chains, sheets, and rings
• Usually combined with H and often
bonds with O, S, N and P
Forms
HYDROCARBONS
Carbon Skeletons and Hydrogen Skins
Each C can form a maximum of four single bonds, OR two
single and one double bond, OR one single and triple bond.
The arrangement of C atoms determines the skeleton, so a
straight chain and a bent chain represent the same
skeleton.
Groups joined by single bonds can rotate, so a branch
pointing down is the same as one pointing up.
The Other Carbon Bonds
• If carbon is not bound to anything else in an
organic compound, it will be attached to
hydrogen.
C –C– C – C – C
|
C
Ways of depicting formulas and models of an alkane.
ring
Some five-carbon skeletons.
C
single bonds
C
C
double bond
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
Saturated and Unsaturated
• When the carbon in organic compounds
forms only single bonds we say that the
compound is saturated (can’t add
anything more).
• If there are double or triple bonds,
these can be broken to add more atoms.
In this case we say that the compound
is unsaturated.
Isomers
• When two compounds have the same
chemical formula but different
structural formulas they are called
isomers.
• There are many kinds of isomers
depending on where the carbons are
placed and how bonds are arranged.
Isomers and Vision
• If you take beta carotene and split the
molecule, you get 2 Vitamin A molecules.
These are related to retinal.
• Retinal changes form when a photon of
light strikes it.
• http://www.elmhurst.edu/~chm/vchemb
ook/531vision.html
Depicting cycloalkanes.
H
H
C
H C
H
C H
H
H C
C H
H C
C H
H
H
cyclobutane
cyclopropane
H
H
Boiling points of the first 10 unbranched alkanes.
An analogy for optical isomers.
Some molecules with the alcohol functional group.
Some common aldehydes and ketones.
methanal
(formaldehyde)
used to make
resins in plywood,
dishware,
countertops;
biological
preservative
ethanal
(acetaldehyde)
narcotic product of
ethanol
metabolism; used
to make perfume,
flavors, plastics,
other chemicals
benzaldehyde
artificial almond
flavoring
2-butanone
2-propanone
(methyl ethyl
(acetone) solvent for
fat, rubber, plastic, ketone) important
solvent
varnish, lacquer;
chemical feedstock
Some molecules with the carboxylic acid functional group.
methanoic acid
(formic acid)
an irritating
component of ant
and bee stings
benzoic acid
calorimetric
standard; used in
preserving food,
dyeing fabric, curing
tobacco
butanoic acid
(butyric acid)
odor of rancid butter;
suspected component
of monkey sex
attractant
octadecanoic acid
(stearic acid)
found in animal fats;
used in making candles
and soap
Some lipid molecules with the ester functional group.
cetyl palmitate
the most common
lipid in whale
blubber
lecithin
phospholipid found in all cell membranes
tristearin
typical dietary fat used as an
energy store in animals
Polymers
• Long chain molecules made of small
repeating units
• Can be made by addition reactions
(adding molecules) or condensation
(splitting something out and joining the
pieces.
• Building polymers….
Crosslinking
• Some polymers make bridges across
chains rather than just adding to chains.
These are “cross-linked” polymers.
• Some cross-links are covalent bonds and
are permanent. Some links are made
with intermolecular forces and can be
broken more easily (like the alginate
worms).
Making “Worms”
Sodium alginate
Calcium alginate – the
calcium ions replace
the sodium ions and
form a “bridge”
between parts of the
alginate molecule
Making Slime
PVA (poly vinyl alcohol)
glue molecule
Borax molecule
PVA (poly vinyl alcohol)
glue molecule