Esters Flashcards
What is the functional group of Esters?
‘-COO-‘
How are esters formed? What is this reaction called?
From an alcohol and a carboxylic acid. It is called esterification
What is a catalyst used for an esterification reaction?
A strong acid catalyst likst concentrated sulfuric acid
Are Esters volatile or not volatile?
Volatile
Name 4 uses of Esters
- Perfumes
- Flavourings
- Solvents in paint, nail varnish remover ect
- Plasticisers
What are fatty acids?
Carboxylic acids with long chains
What do fatty acids and glycerol combine to make?
Fats and oils
What bonds do saturated compounds have?
C-C single bonds
What bonds do unsaturated compounds have?
C=C double bonds
Do animal fats normally have saturated or unsaturated hydrocarbon chains?
Saturated
What state are they at room temperature?
solid
Do vegetable oils normally have saturated or unsaturated hydrocarbon chains?
Unsaturated
What state are they at room temperature?
Liquid
What two chemicals make an ester?
An alcohol and a carboxylic acid
Is the reaction of making an ester reversible or not?
Yes, it is reversible
What are the 4 steps involved in making an ester?
- Refluxing
- Distillation
- Purification
- Drying
Describe the process of Refluxing
The carboxylic acid and the alcohol are gently heated in a flask with a condenser.
What is the purpose of the Distillation stage?
It separates the ester from other stuff left in the flask, such as unreacted alcohol & carboxylic acid, sulphuric acid and water
How is the distillation stage carried out?
The mixture is heated below a fractioning column. When the temperature at the top of the column reaches the boiling point of the desired ester then the liquid flows down the condenser and collected.
What is the liquid collected after the distillation process called?
The distillate
What are the two substances mixed with the distillate during the purification stage?
Sodium carbonate solution
Concentrated calcium chloride
How is any remaining water removed in the drying process?
It is mixed with lumps of anhydrous calcium chloride and then separated by filtration
