Functional Groups

First up is Alkenes. Alkenes are hydrocarbons with one or more double bonded carbons. They are insoluble in water, and relatively stable, though the double bond in between the carbons cause it to slightly reactive. Alkenes are often used in the formation of plastics.

Next are Alkanes. An alkane has no functional groups. It is simply single bonded carbon and hydrogen atoms, like propane or butane. They are mainly used in combustion reactions. They are relatively unreactive, which is why substances like gasoline or oils can be stored for extended periods of time. 

Alkynes are like Alkenes, except for triple bonds, not doubles.  A common example of a compound with an alkyne group is acetylene, used in many fuels. They are more reactive than Alkenes due to the extra pi bond between the two carbons.

Next are alcohols. Alcohol groups are hydroxyl groups (OH) attached to a carbon atom by a single bond.  These groups are attracted to one another, forming strong intermolecular forces and giving alcohol groups a high boiling point. Ethanol is a common compound with an alcohol group. 

Ethers  are two chains of carbon, with a oxygen atom in between.  Since the oxygen is attached to two carbons, it cannot form hydrogen bonds like alcohol groups do. This leads to a lower boiling point. Ethers are commonly seen in fats, gum and dyes. 

Esters are similar to ethers, except now there is an oxygen atom double bonded to one of the carbons in which another oxygen is attached to. Again, these do not participate in hydrogen bonding. They are fairly reactive due to the doubled bonded oxygen. Many nail polish removers get their strong smell from ester groups. 

Carboxyl groups are next. They are very similar to esters, except for the oxygen being attached to another chain, it is attached to a single hydrogen. This allows the compound that it is in to participate in hydrogen bonding, raising its boiling point. An example is acetic acid found in vinegar. Any compound with it will end in -onic acid

Amines are the first group to include nitrogen. an amine group is a nitrogen bonded to three separate atoms. Their structure is similar to ammonia, but with at least one carbon instead of all hydrogen. Amines are commonly seen in the pharmaceutical industry. (Note this a secondary amine with 2 carbon groups, it could also have 2 H and 1 R, or 0 H and 3 R)

Thiols are much like alcohols, although instead of an oxygen, thiols have a sulfur. They have a low boiling point, and are often recognizable for their strong odors. Skunk spray contains thiol groups, giving them their signature way of protecting themselves. Additionally, the strong smell of thiols is used to add odor to natural gas, since it usually has no scent. 

Lastly, there are aldehydes. These are very similar to carboxyl groups, but the hydroxyl group bonded to the central carbon is just a hydrogen now. This disallows hydrogen bonding.  A common substance with this group is formaldehyde, a compound used in preservation of wood, finishes, and fertilizers.