Unit 2(b) Esters, Fats And Oils Flashcards
How are esters formed?
Condensation reaction between an alcohol and a carboxylic acid
What molecule is eliminated when an ester is formed?
Water
How are esters named?
First word - parent alcohol, ends in -YL
Second word - parent acid, ends in -OATE
What is the catalyst for the production of esters?
Concentrated sulphuric acid
Why is a cold paper towel used in the production of esters?
Acts as a condenser
How can an ester be detected?
Immiscible layer on the surface of the solution
Characteristic sweet smell
What are some uses of esters?
Flavourings, solvents, perfumes
How can esters be broken back down into their parent alcohol and acid?
Hydrolysis
What is the formula for an ester link?
-COO (one O is double bonded)
Why are there high concentrations of esters in the air?
Esters are volatile
What does VOC stand for?
Volatile Organic Compounds
What are fats and oils examples of?
Esters
What are some properties of fats and oils?
Concentrated source of energy
Slow release of energy
Greasy
Used as fuels and lubricants for agricultural machinery
What 3 groups can fats and oils be classified as?
Animal source
Vegetable source
Marine source
What problems are associated with fats and oils in the diet?
(Saturated) fats are linked to heart disease
However, some essential vitamins are only found in fatty foods
What molecules are fats and oils formed from?
Glycerol and 3 carboxylic acid molecules - fatty acids
What is glycerol?
Propane-1,2,3-triol (glycerol) is a triol, so 3 -OH groups are present
How many ester links does a fat/oil molecule have?
3
What is produced on the hydrolysis of fats and oils?
Fatty acids and glycerol at a ratio of 3:1
Why do saturated fats have higher melting and boiling points than unsaturated fats?
Saturated molecules have no double bonds, so can pack closely together, allowing maximum LDF.
Unsaturated molecules are bent at the double bonds, and so are unable to pack together, resulting in less LDF so a lower melting point
Do fats and oils decolourise bromine?
Oils do, fats don’t
How can oils be converted into fats?
Hydrogenation
What is ‘hardening’?
The process by which unsaturated oils are made more saturated, creating healthier spreads such as margarine
What is hydrogenation?
Addition of hydrogen
What is dehydrogenation?
Removal of hydrogen
What is hydration?
Addition of water
What is dehyration?
Removal of water
What is condensation?
Formation of 1 large molecule from 2 smaller molecules with the removal of water
What is hydrolysis?
Splitting of 1 large molecule into 2 smaller molecules using water
