More Organic Reactions

The two sets of reactions we have seen so far (oxidation / reduction and substitution / elimination) have fit into nice pairs. However, there are still more types of organic reaction to go over.

First are addition reactions. Addition reactions occur when an atom or group is added to an unsaturated molecule, making one product. Unsaturated means that an atom (usually carbon) has not formed its maximum amount of bonds. There are two special groups of addition reactions, hydrogenation (adding H2) and hydration (adding H2o). Hydrogenation changes an alkene to an alkane or a alkyne to an alkene. Simply put, hydrogenation bumps a molecule down one on the functional group ladder. Hydrogenation is seen in the real world through vegetable oil. Vegetable oil is made up of long carbon chains with carboxyl groups at the end, known as fatty acids. These strands are unsaturated. When hydrogen gas is blown on the oil, it changes states from a liquid oil to solid fat. If you see "hydrogenated" on a food product like margarine, know that products has undergone this process.

Hydration is the other special sub-group of addition reactions. This one may be a little more intuitive than hydrogenation. Adding water to organic chemicals do not simply dilute them, but sometimes causes them to react. Hydration mostly occurs with alkenes, turning them into alcohols. This serves as a secondary process by which ethanol can be made, by hydrating ethene. Watch this video to get a more in depth explanation of addition reactions.

Next are condesation reactions. In this type of reaction, two molecules condense to form one larger molecule. Water is often produced in this process. This quick video showcases a real world example of this process.

Think you know these reactions? Take the quiz to find out!