Akenes and Akynes

Last class we looked at Alkanes which is the bonding of organic chemistry.

Today we looked at alkenes and alkynes which is double and triple bonding of carbon.
Some basic notes are

• when multiple bonds form fewer hydrogen atoms are attached to carbon atoms
• Carbon always needs 4 bonds
• naming rules are almost the same
• - position of the double or triple bond has lowest number and is put in front of parent name

Alkenes

• organic compound with a double bond
• ending is changed from -ane of alkanes to -ene of alkenes

i.e. CH2=CH2  -> ethene
      CH2=CH-CH3  -> propene


Rules for naming

1. find longest Carbon chain and place at end of name
2. number the Carbon atoms to get the lowest number to start of the double bond and place the number before the parent name
3. assign names and numbers for all sides groups and assemble the name alphabetically

 Geometric Isomeres

• same chemical formula but different geometry

opposite groups on top and bottom       identical groups on top or bottom

trans-2-Butene

cis-2-Butene

Alkynes

• triple bond
• ending chaged from -ene of alkenes from -ane of alkanes to -yne for alkynes

example

 



If this is all super confusing it will get easier!

Organic Chemistry

last class we went over the chemistry of Carbon Compounds

Some examples of organic compounds that we are familiar with are:
Clothing - polyester
Plastics - polyethylene alcohol

their properties include:
*low melting points
*weak or non-electrolytes
*can form chains or carbon atoms that are linked in a:
   - Straight Line (which is not actually straight, but a zig zag line)
   - Circular Pattern
   - Branched Pattern
*can link with other atoms in
   - Single Bonds

   - Double Bonds
   - Triple Bonds
   - Versatility

Alkanes Hydrocarbons
-A hydrocarbon is a compound that contains only hydrogen and carbon. There are different types of hydrocarbons and there re different ways to represent them
-Alkanes are saturated hydrocarbon which have all carbon atoms bonded by single bonds to the structure
-to NAME alkanes: they all end with "-ane"
here is a chart to show the names and molecular formulas of alkanes

 To help get the molecular formula follow this formula: CnH2n+2
Branched Hydrocarbons
-Hydrocarbons have "side branches" which are also hydrocarbon chains. These hydrocarbons are called substituted hydrocarbons or branched hydrocarbons

-An Alkyl group is an alkane which has lost one hydrogen atom
-NAMING an alkyl group always end with "-yl"





Here are the RULES you should follow to successfully name branched chain alkanes:
1) Identify the longest, continuous carbon chain, and name it (using the chart above)
2)Identify the branches the come off the main carbon chain
3)number the carbons in the main chain by placing the lowest possible number to the first branch
4)Identify which carbon the branch is located
5)Name the branch
6)When writing it out the branch name comes before the main chain name (ex. methylpentane)

 *forming a branched hydrocarbon is when it gets tricky! but have no fear! here is a helpful video to better explain the process since it is very difficult to draw examples on this blog

HELPFUL VIDEO!! warning: may feel super smart after watching

http://www.youtube.com/watch?v=YWA5SfJhWKI 

Today we worked on Chemical bonding, Electrostatic force, and Polarity!

Starting this I always got confused with non polar, and polar covalent bonds, so here is the difference

• if electrons are shared equally, a non polar covalent bond is formed
• if electrons are shared unequally, a polar covalent bond is formed

Pretty much all of this stuff was review today so i'll catch you up on what we did.
Starting with electrostatic force we reviewed that

• opposites atrract
• like charges repel
• the greater the distance the smaller the attraction
• greater charge the greater the atraction
• electrostatic force exists between charge particles as a result of attraction or repulsion
• force around an atom is equal in all directions
• metals have a low electronegativity values
• non-metals have high electronegativity values
• atoms with high electronegativity values have high ionization energy because they strongly attract their valence electrons and thus are difficult to remove

electronegativity is essential how well an atom sticks to another one
there are two bonds that we learned today:
intramolecular bonds hold atoms together > strong bonds
intermolecular forces between molecules > weak bonds

 






Next we looked at Polarity

• describes molecules electrical balance
• if imbalance with electrical charge, then molecule is polar
• if same strength all sides then non-polar
• higher energy will form partial negative charge
• lower energy will form partial positive charge

That concludes todays lesson!