Unit 2 - Esters, Fats and Oils Flashcards
What are esters defined as
molecules that contain the ester link -COO
what two types of molecule make up an ester?
an alcohol and carboxcylic acid
what is the reaction called that forms an ester?
a condensation reaction
condensation reaction
is where the two molecules join together with the elimination of a smaller molecule
in a condensation reaction what is the small molecule that is eliminated?
water molecule
what catalyst is normally used to speed up the reaction?
concentrated sulphuric acid
what is a condensation reaction making an ester also known as
estrification
explain what happens to the structure of the alcohol and carboxcyclic acid in a condensation reaction
the OH from the carboxyclic acid and the H from the OH in the alcohol break off to form a water molecule. The remaining parts join to form the ester link.
what does the catalyst do other than speed up the reaction
it increases the yield of the ester produced.
what is the functional group of an ester.
O
=
R - C - O - R
hydrolysis reaction
where a molecule is broken up using the elements of water, allowing it to be hydrolysosed back into the alcohol and carboxcylic acid it came from
example of when hydrolysis occurs naturally
- Perfumes going off
- Acetone hydrolysing into ethanoic acid
what is the practical technique we can use to carry out hydrolysis
heating under reflux
why does water flow through the bottom in a condenser
this is because there are likely to be air pockets which will result in poor condesation if it enters from the top.
why are anti-bumping granules used?
becuase they are inert and help the mixure boil more smoothly.
what catalysts can be used in this reaction?
- Strong acid (H+ Ions) called acid hydroylsis.
- Strong Alkali (OH- Ions) called alkali hydrolysis
why is alkali hydrolysis better?
becuase it produces the alcohol and the salt of the carboxcyclic acid as the acid formed is immediately neutralised by the alkali.
proply ethanoate + water —-(Sodium Hydroxide)—>
propanol + sodium ethanoate
examples of uses for esters
- nail varnish
- perfumes
- artificial fruit flavourings
features of esters
- volatile
- low polarity
- contain the ester link -COO
what alcohol are the esters of fats and oils made from?
glycerol
what is the difference between fats and oils?
their state at room temperature: fats are solid oils are liquid.
why are fats and oils so important for us?
- Fats and oils are a concentrated source of energy .
- Essential for the transport and storage of fat soluble vitamins in the body
example of animal , plant and marine fats/oils
Lard, olive oil, fish oil
