Organic Chemistry

Oils and Fats

            Fats and oils are essentially the same type of material. The difference (with a few exceptions) between 

the two is that, at room temperature, oils are liquids and fats are solids.  Collectively, fats and oils are referred 

to as triglycerides, as they are made up of glycerol and three fatty acids connected through a dehydration 

reaction.

            Triglycerides are hydrophobic, meaning they “fear water.”  This means that no fats or oils will dissolve 

in water.  They are slightly more soluble in ethanol than they are in water, but are still not very soluble.  The 

solubility of triglycerides in acetone is much higher than either ethanol or water.  When soap is mixed in with a 

triglyceride and water, it acts as an emulsifying agent and disperses the triglycerides with the water in tiny 

bubbles.  Sudan III is a dye in which fats and oils dissolve.  If water is added to Sudan III, they wouldn’t mix but 

something like olive oil would.

            It can be concluded that triglycerides are good sources of energy because when they are burned, a 

great orange flame is made. It lasts for a while, depending on how much material is being burned.  A black 

deposit (carbon) is left behind after the flame. If water was added to this fire, instead of putting the fire out as 

expected, it only makes the fire spread out.  This is because the oil being burned is hydrophobic and is pushed 

away by the water, only to make a larger fire.