Thursday, May 26, 2011

Organic Chemistry - May 26, 2011 - Isabelle Cheng

Isabelle Cheng
Block 2-2
Chemistry 11 Ms. Chen
Organic Chemistry
What is organic chemistry anyway?.....
Organic Chemistry:
introduction to the diverse chemistry of carbon
scientific study of the structure of carbon-based compounds and hydrocarbon
can vary from small to large
has a specific naming system 
different kinds of structures to represent a molecular formula
form chains of carbon atoms

A carbon that has 4 bonds

A carbon atom that has 4 hydrogen atoms

A carbon-carbon bond

Branched Chain

There are certain names for each molecular formula!
1 - meth
2 - eth
3 - prop
4 - but
5 - pent
6 - hex
7 - hept
8 - oct
9 - non
10 - dec 
You use these prefixes in the beginning and the endings for alkanes is “-ane.”
The formula is CnH2n+2, if you plug in the numbers and it doesn’t work then that means that it is not from the alkane group!
When looking at the structures: Always look at the longest chain and write the molecular formula from there!
For example:

It is called Propane because there are three of the longest chain. 
For the Alkayl group, they have a different formula and different naming system:
The ending is “-yl,” so an example would be methyl. 
For example:

This structure is called 3-methyl-pentane because the bond is on the third position and it is called methyl because it is from the alkyl group. It is called pentane because the longest chain has 5 of them. 
Extra facts: The sum of all valence e- of each atom in the molecular formula must equal the number of electrons in your Lewis Dot Structure.
Except for a few elements, ex. H, most elements want a full valence shell. 

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