esters Flashcards
How are esters made?
formed by reacting an alcohol with an carboxylic acid by removing water.
What kind of reaction forms an ester?
a condensation (or esterification reaction) as large molecule formed by removing smaller molecule, in this case water.
How to name esters…
first part of name (-yl) comes from the alcohol.
second part (-oate) from the acid.
Can esters H-bond?
Cannot hydrogen bond as doesn’t contain -OH, so doesn’t dissolve in water.
Uses of esters…
Many have pleasant fruity smells and are often used in scented products such as perfumes.
Pleasant tasting esters are used as flavourings.
Also used as solvents for non-polar compounds.
What chemical is used to shift the equilibrium to the right in an ester reaction?
Concentrated sulphuric acid as it has a high affinity for water and removed it to shift equilibrium to the right to produce more product (ester).
Why is the reaction mixture of esters heated in a water bath?
Because the chemicals are flammable so a bunsen cannot be used as risk of fire.
Whys is ester reaction mixture poured into sodium hydrogen carbonate solution?
To neutralise any leftover sulphuric acid.
What happens when an ester reacts with water?
Ester hydrolysis - breaks down to form the parent alcohol and parent carboxylic acid.
What is used to catalyse ester hydrolysis?
an alkali, e.g. sodium hydroxide, it causes a salt to form with the acid which can be reacted with a strong acid to displace the acid from the salt.
Alkali hydrolysis…
Is not reversible.
Results in higher yield of products.
Makes it easier to separate the products
