Unit 2: Chapter 6 - Oils and Fats Flashcards
What is the difference between fats and oils?
The ‘degree of saturation’
In fats what are the hydrocarbon chains like and what does this mean for the compound?
In fats the hydrocarbon chains are ‘saturated’. this allows the molecules to pack neatly together meaning the LONDON DISPERSION FORCES ARE STRONG. Due to this the compound is SOLID.
In oils what are the hydrocarbon chains like and what does this mean for the compound?
In oils the hydrocarbon chains are ‘unsaturated’, the double bond creates a bend i the hydrocarbon chains pushing the molecules apart meaning the LONDON DISPERSION FORCES ARE WEAKER. Due to this the compound is LIQUID.
What are oils and fats both in water and what does this mean they can be called?
Oils and fats are insoluble in water and can be called ‘hydrophobic’.
What does ‘hydrophobic’ mean?
Water hater.
If molecules contain an OH group are they always soluble in water?
No it depends the size of the rest of the molecule that is insoluble. i.e. if a molecule has 1 OH and the rest is covalent bonds, then most of the molecule is insoluble so no it is not soluble in water. However if the molecule contains a few OH groups with not as much of the molecule being insoluble in water then the molecule will be soluble in water and can be called hydrophillic.
What does hydrophillic mean?
Water lover.
What is turning an oil into a fat commonly known as?
Hardening
What does the process of hardening usually involve?
Passing hydrogen, which is under pressure, through a hot oil.
What is the process of adding hydrogen called?
Hydrogenation
What does hydrogenation do in the process of turning oils into fats?
It encourages an addition reaction where the hydrogen adds on to the c=c in the fatty acid chain. Hence decreasing the unsaturation of the oil, increasing the melting point and creating a fat.
What is an example of turning an oil into a fat?
Sunflower oil + Hydrogen = Sunflower margarine.
What do fats and oils consumed in our diet provide us with?
The fats and oils consumed in our diet provide the body with a concentrated source of energy(even more than carbohydrates) and are essential for the transport and storage of fat-soluble vitamins in the body .
What is a disadvantage to fats and oils in our diet?
The are a major source of heart disease and coronary problems.
What are fats and oils in terms of esters?
Edible fats and edible oils are esters formed from the condensation of glycerol (propane 1,2,3-triol) and three carboxylic acid molecules.
What are the variety of carboxylic acids also called in fats and oils?
Fatty acids.
What do the fatty acids in fats and oils contain?
Fatty acids contain only one carboxyl group attached to a long hydrocarbon (alkyl) chain.
or
fatty acids and can be saturated or unsaturated straight-chain carboxylic acids, usually with
long chains of carbon atoms.
In fats and oils what is the only alcohol called?
Glycerol
What is the structure of glycerol like?
Glycerol is a complex alcohol as it has three -OH group and is a triol.
Do edible oils have lower melting points than edible fats?
YES
What does the double bond in fatty acids prevent happening in oils and what does this mean for the properties of oils?
Double bonds in fatty acid chains prevent oil molecules from packing closely together, so the greater the number of double bonds present, the weaker the van der Waals forces of attraction. The greater the degree of unsaturation, the lower the melting point.
When a fat or oil forms through a condensation reaction, each glycerol molecule can form what with what molecules?
An ester link with three fatty acid molecules.
As all fats and oils contain the ester link what can they be classified as?
Esters
What do we use to break down a fat or oil?
The hydrolysis(alkaline) reaction with superheated steam.
