Organic Chemistry
Introduction
Brainstorming Activity
Organic Chemistry
• Organic compounds are everywhere
• It is defined as the chemistry of the carbon
compound
• Hydrogen atoms typically accompany the
carbon (hydrocarbon)
• Over 8 million organic compounds
Organic Compounds in real life
worksheet
Alkanes
• Lewis Structures
– Carbon has 4 bonds
– Hydrogen has 1 bond
Alkane representation
• Structural Formula
• Condensed formula
– CH4
– CH3–CH3
• Molecular formula
– CH4
– C2H6
What is a way to remember the
molecular formula?
Straight Chained Alkanes
• All alkane’s end in –ane
• Saturated = each carbon has the maximum
number of hydrogen's attached
• Geometry of an alkane is not straight
– It is bent!
– To make sure all hydrogens are as far away from every
other hydrogen
– 109° between every single H-C-H bond
– Tetrahedron
– The bonds can rotate freely in an alkane
Branches
• Hydrocarbons aren’t just straight chained
alkanes
• They can have branches!
• We call these side branches, alkyl groups
– The end of alkyl groups end in –yl
• Branches can be as long as they want
wherever they want
• -CH3CH2CH2CH3 is a butyl branch
How do we name the branches?
• Name the longest chain possible
– This is the parent chain
• Number our parent chain from 1
– Can number from any direction
• You want to make sure your branches have the lowest
combined set of numbers.
• List your alkyl groups and their numbers.
• Put them in alphabetical order based on alkyl group
– Ethyl before methyl
• Name them by # of where they are, then a dash, then
the alkyl group, then the alkane
Naming
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#-alkylalkane
2-methylpentane
3-ethyl-2-methyloctane
3,3-dimethylhexane
2,4-dimethylheptane
2,3,4-triethylnonane
How carbons bond
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Carbon has 4 bonds
Carbon without any other carbon is CH4
Carbon with 1 carbon attached to it becomes CH3
Carbon with 2 carbons attached to it becomes
CH2
• Carbon with 3 carbons attached to it becomes CH
• Carbon with 4 carbons attached to it becomes C
Structural Isomers
• Are where the hydrocarbon has the same
number of carbon’s and hydrogen’s, but can
be rearranged differently
• Example C4H10 and C5H12
Properties of Alkanes
• Structural isomers each have their own
properties based on arrangement
• Properties also vary based on chain length
– Methane to propane are gas at room temperature
– Pentane to C15H32 are liquid at room temperature
– C16H34 and longer are solid at room temperature
Cycloalkanes
• This is where the carbon chain is no longer a
straight line, but looped
• Example
– C3H6
– C5H10
• Cycloalkanes are all CH2 groups unlike straight
chained alkanes
Naming Cycloalkanes
• We name all our cycloalkanes the same, except we add
cyclo to the front
– Cyclopropane
– Cyclobutane
– Cyclopentane
• What if we have branches?
– We follow the same naming pattern
– Except, if we have 1 branch, we do not need to put a
number
– If we have more than 1 branch, we add numbers where
the first branch alphabetically is 1 and we go around to
form the lowest number possible
Alkyl Halides
• They are like alkyl groups, but are halogens
• Same naming system has halides when they are
part of a branch
• Fluorine = fluro
• Chlorine = chloro
• Bromine = bromo
• Iodine = iodo
• Example
– 2-fluropentane
Alkyl Halides
• Alkyl halides have special properties based on
their branch and number
• They can be unreactive and inert such as
fluoro halides
– Teflon is a fluoro halide and is unreactive and inert
Multiple Bonded Carbon chains
• Double bonded carbon-carbon is called
Alkene
– Their names end in -ene
– C=C
• Triple bonded carbon-carbon is called Alkyne
– Their names end in –yne
– C≡C
What do they look like?
• Ethane
• Ethene
• Ethyne
Unsaturated
• Because these carbons do not have full
number of hydrogen’s around each carbon, we
say they are unsaturated
To name multiple bonded carbon
chains
• We number the carbon chain so that our
double bonded is the lowest number possible
• We name it based on the first carbon of the
double bond and its number
• 3-pentene
• 4-heptyne
• To write the condense structure, do it like
usual, except we put a double or triple bond
where it is
Geometry of alkene and alkyne
• The geometry of multiple bonded carbons is a
planar/flat molecule
• This is due to no rotation around the bond
and how the bonds are bonded
• Very rigid
Aromatic Compounds
• Are compounds that contains 1 or more
“benzene” rings
Aromatic Compounds
• Aromatic comes from the word aroma
• They smell, sometimes good, sometimes bad
• We name aromatic compounds the same as
we do with cyclic molecules
• The ending is benzene
• Example
– 1,2-methylbenzene
Functional Groups
• Specific groups of atoms that exist in
molecules that gives the molecule special
properties and reactivity
• They are what turns organic compounds into
alcohols, acids, bases, soluble, insoluble,
explosive, or smelly
Alcohols
• Are compounds that have an –OH at the end
of the chain
• Their names end in –ol
• Methanol = CH3OH
• Ethanol = CH3CH2OH
• 2-Butanol =
Properties of Alcohols
• The –OH group makes the organic compound
soluble in water up to a certain length of the
carbon chain
• Shorter chains are soluble
– Up to propanol
– Longer chains such as pentanol are insoluble in
water due to the carbon chain being non-polar
• Alcohols are poisonous!
– Ethanol is just less poisonous, but still is.
Aldehydes
• Are groups that contains –CHO
• The –CHO group is always at the end of a
chain
• Their names end in –al
• Methanal
• Propanal
Ketones
• Are like aldehyde’s, but the C=O is not at the
end, but is in the middle
• Their names end in –one
• To name, we put a number and dash to where
the C=O is
• 2-butanone
Ethers
• Are anesthetic compounds that can be used in
hospitals to put people to sleep
• They are where the oxygen splits the carbon
chain
• To name, we separate the two carbon chains
into their own carbon chain groups
• We name the SHORTER chain with the ending
–oxy
• methoxypentane
• ethoxybutane
Amines
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Carbon chain that ends with NH2
Smells like fish
Acts as a base
Their names begin with amino
Aminoethane
• aminopentane
Amides
• They are like aldehyde’s, but the H is replaced
with an NH2
• You name it by putting amide at the end of
the name
• Ethanamide
• propanamide
Carboxylic acids
• Are acids that contains the –COOH group
• Like an aldehyde where the H is replaced by an –
OH group
• Names all end in -oic
• CH3COOH is ethanoic acid/acetic acid/vinegar
• HCOOH is methanoic acid
Esters
• Are where the end carbon is double bonded
to one oxygen and single bonded to another
• The single bonded oxygen is then bonded to
another carbon chain
• Sort of like an ether and ketone
Esters
• Their name ends in –oate
• The carbon side chain is named –oate
• The oxygen side chain is named as an alkyl
group
• Methylbutanoate
• ethylpropanoate
Summary Sheet
Homework
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Page 242
#38 (a,c,e odd)
#39 (a,b,e,p,q,r)
#44 (a, c, e odd)