Organic Chemistry

These are examples of an organic compound.

Organic compounds are the compounds containing carbon in it.When the organic compound is burned, it produces carbon dioxide. It has low melting points, and it is weak or non- electrolytes.

Organic compound forms chains of carbon atoms in three different patterns:

Straight

Circular

Branched


*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--


Today, we are going to look close at Hydrocarbons

☆Alkanes (straight chain)

Alkanes is the hydrocarbon ( containing H & C). Alkanes are satuated, meaning that all carbon atoms are bonded by single bonds so no other atoms can bond to it. There are variety of types and different ways to represent them.

Their name end in '-ane' (ex, methane, octane)
To name Alkanes, put prefixes infront of '-ane' according to the number of carbons.
 

Series of organic compounds with a similar general formula and properties ( just like the one above) are called the homologous series.

☆Alkyl Group

Alkyl group is the alkane that has lost one hydrogen. This group occurs in the branched hydrocarbons.



Naming Hydrocarbons

Here is the steps you should take when naming the hydro carbons with only one bond.

1. Find and name the longest continuous carbon chain and place at the end of the name.
   (ex. diagram below; carbons in the blue rectangle → butane)
2. Identify and name groups (ex. diagram below; red circle → methyl) attached to the chain.
3. Number the chain from nearest side (from the group) to the other.
4. Represent the location of each side group by an approperiate numbers and names.
5. Assemble the name, listing groups in alpha betical order.

Ex. 2,3-dimethylbutane

*more than one of the same kind of alkyl grops are represented using prefixes (ex. di, tri,)





☆Alkenes


Alkenes are just like the Alkanes, but with one or more double bonds.
Alkenes are unsaturated hydrocarbons and are generally very reactive.
Alkenes end with "-ene"

Example: These are all homologous alkenes. As you can see, they all have double bonds.

☆Alkynes

Similarly, Alkynes are the hydrocarbon with one or more triple bonds.
Alkynes are unsatuated and they end with "-yne"

Example:

You would take same steps to name Alkenes and Alkynes as Alkanes EXCEPT that you are numbering the chain from the side closer to the double or triple bond. For example, on the example above, there is a triple bond located closer to the left end of the chain. So, you would have to number chain from left to right.... the name would be 5-methal-2-pentyne


If the geometry happen to have more than one bond, state the position of the bonds and add prefixes in front of "-ene" or "-yne" (ex. 3,7-decadiene)


Since same formula can have different geometry, (= Gemetric isomers) "Cis" and "Trans" are put in front of the name of hydrocarbons to identify the geometry.

 This kind of geometry, with larger group (☆) above is named with "Cis"

This kind of geometry, with larger group (☆) located vertically is named with "Trans"

No need to write "Cis" nor "Trans" for this kind :)

This video will help you understand more about hydrocarbons.