Unit 2-Esters, Fats And Oils Flashcards
Describe how to identify an ester: 1. From the name 2. From a structure
- The name ends in -yl -oate
- The structure contains the –COO– functional group
What are the steps needed to name esters?
Change the alcohol name to end in –yl. Change the acid name to end in –oate. Alcohol name goes to the front, acid name to the back.
Describe characteristics and uses of esters.
Characteristic (fruity) smells and are used as flavourings and fragrances. also used as industrial solvents.
Give an example of the name of an ester.
Methyl methanoate
Ethyl propanoate
Propyl pentanoate
Describe the reaction which forms esters.
Formed by the condensation reaction between carboxylic acid and an alcohol.
Ester link is formed by the reaction of a hydroxyl group and the carboxyl group. Water is eliminated.
What type of reaction will break up an ester into an alcohol and carboxylic acid?
Hydrolysis
What two types of compounds react together to make fats and oils?
Glycerol (propane-1,2,3-triol) and three carboxylic acid (fatty acid) molecules.
Do fats or oils have higher melting points?
Fats have higher melting points.
Do fats or oils have more double bonds (higher degree of unsaturation)?
Oils have more double bonds than fats
Why do more double bonds cause a lower melting point?
Double bonds stop oil molecules from packing closely together and makes the London dispersion force weaker than between fat molecules.
How can oils be converted to fats?
Oils can be converted to fats by hydrogenation, an addition reaction with hydrogen.
Why do humans need fats and oils in their diet?
To provide us with energy. Play a role in the transport of vitamins which are soluble in fats around the human body.
