GEMS 160
Feb 20, 2006
• No Chem News articles yet this week
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Notebooks back by next Monday
Exams back by Wednesday
Next two weeks, Ch. 6, 7, (8 ??) organic chemistry
Ch. 6 homework posted to discussion board, due 2/27
Keep ahead with the reading
• Chem in the news
– Today: John Schaftenaar
– Wednesday: Jon VanWyngarden, Jenna Rykse
(info by 8:00 pm today)
– Friday: Julie Robinson, Jason Burns
FDA re-opens probe into benzene
contamination of soft drinks: John Schaftenar
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Benzene has been found in soft drinks during testing by the FDA
at levels above the legal limit. This a problem that occurred
before in the early 90's, but is now occurring again.
Benzene is a poisonous chemical that has been known to increase
the risk of leukemia and other cancers.
The problem of benzene in drinks is caused by 2 ingredients in
soft drinks: Sodium Benzoate, also known as E211 and Ascorbic
Acid. These 2 chemicals can react together to form benzene.
There have been more than 1500 drinks launched in the U.S. and
Europe since 2002 that contain these chemicals.
The FDA has stated that they are calling for a reformulation of
these beverages to the National Soft Drink Association, and that
the actual risk to consumers is minimal because the negative
effects of benzene are caused from a lifetime of exposure to it.
http://nutraingredients-usa.com/news/ng.asp?n=65840-soft-drinks-fda-benzene
In compounds carbon will typically have:
Benzoic acid
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World Health Organization (WHO) benzene limit is 10 ppb
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Ascorbic acid is vitamin C
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Sodium benzoate is a preservative to prevent bacterial growth
Chapter 6
“Organic” chemistry
1. relating to living things
2. developing naturally without begin contrived
3. consisting of elements that exist together in a
natural relationship that makes for organized
efficiency
4. agricultural practice that avoids that use of
synthetic chemicals in favor of naturally occurring
pesticides and fertilizers
5. family of compounds characterized by chains or
rings of carbon atoms linked to atoms of hydrogen,
oxygen, nitrogen and sometimes other elements
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2.
3.
4.
5.
A + 2 ionic charge
A + 4 ionic charge
A - 4 ionic charge
2 covalent bonds
4 covalent bonds
Carbon is the cornerstone
• Organic chemistry - the chemistry of carbon
compounds.
• Inorganic chemistry - the chemistry of compounds
that do not contain carbon.
• Why is carbon unique?
• 4 bonds simultaneously
– Relate to the Lewis structure
• covalent bonds with other elements
– As compared to ionic
• molecules with long chains or branches
– Stereochemistry: three dimensional structure
– Tetrahedron: “four faces”, a pyramid
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Welcome to the hydrocarbon family!
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Hydrocarbon - only C and H in formula
Alkanes - only single bonds
Alkenes - compounds with double bonds
Alkynes - compounds with triple bonds
Aromatics - compounds with special rings
http://wps.prenhall.com/wps/media/objects/602/616516/Chapter_23.html
The ALKANE family
Which family of compounds contain
carbon-carbon double bonds?
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2.
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4.
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Aromatic
Alkane
Alkyne
Alkene
How can these molecules be put together?
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How many bonds does carbon have?
How many bonds does hydrogen have?
What does alkane mean?
Structures of:
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Methane
Ethane
Propane
Butane
• Concept of isomers
CH4 methane
C2H6 ethane
C3H8 propane
C4?? butane
General alkane formula CnH2n+2
See table 6.1 and 6.2 for more
Know the names of the “straight” chains
with 1 through 10 carbons
How can these molecules be put together?
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Isomers: same formula, different arrangement of atoms
C4H10
2 isomers
C5H12
3 isomers
C6H14
5 isomers
C15H32
4347 isomers
Drawing and naming simple isomers
– See section 6.8 and 6.9, IUPAC
• Look for longest chain
• Look for branches on the chain
• Number chain so branches have the smallest number
they can
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Some more adjectives to describe the
way molecules are connected
• Primary 1˚
– A carbon atom bonded to only one other carbon
– A hydrogen on a primary carbon
• Secondary 2˚
– A carbon atom bonded to two other carbons
– A hydrogen on a secondary carbon
• Tertiary 3˚
– A carbon atom bonded to three other carbons
– A hydrogen on a tertiary carbon
The ALKENE family
• Ethane to ethene, C2H6 to C2H4
– Common name of ethylene
– #1 in the list of manufactured organic chemicals
– The building block of the polymer polyethlene
• Plastics, synthetic fibers, freezer and trash bags
• Propane to propene, C3H8 to C3H6
– Common name of propylene
– #2 in the list of manufactured organic chemicals
– Another key polymer building block
• General alkene formula CnH2n (one double bond)
The ALKENE family
• General alkene formula CnH2n (one double bond)
• Butene
– 1 butene
– 2 butene
– Isomers of alkenes
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