Unit 2 Oxidation Of Food Flashcards
What is oxidation?
Is an increase in the oxygen to hydrogen ratio
What is reduction?
Is a decrease in the oxygen to hydrogen ratio
What functional group is present in alcohols?
OH
Hydroxyl
Ol
What can alcohols be used in and why?
Are flammable and can be used as fuels
Can be burned to release energy
What are alcohol with different amounts of hydroxyl groups called?
Diols 2
Triols 3
What happens to a alcohol as the number of hydroxyl groups increases?
The number of hydrogen bonds that can form increases
As number of hydrogen bonds increases the strength of intermolecular bonding increases
As strength of intermolecular bonding increase the mp/bp will increase and alcohol will become more viscous
What are the different types of alcohol?
Primary-hydroxyl attached to C bonded to atleast 2 H
Secondary-hydroxyl attached to C bonded to one H
Tertiary-hydroxyl attached to C bonded to no H
What can alcohols be oxidised to?
Primary-aldehydes-carboxylic acids
Secondary-ketones
Tertiary cannot be oxidised
What are aldehydes and ketones functional group.
Carbonyl group
C=O
What are aldehydes and ketones naming process and where are functional groups found?
Aldehydes
-al(ethanal)
Carbonyl always on carbon 1
Ketones
-one(propanone)
Carbonyl not on carbon 1
What can aldehydes and ketones be oxidised to?
Aldehydes-carboxylic acids
Ketones cant be oxidised
What oxidising agents can be used to oxidise aldehydes and there results?
Fehlings-blue to brick red
Tollens reagent-formation of silver mirror
Acidified potassium dichromate-orange to green
No reaction in ketones/tertiary alcohols
How can carbolic acids form aldehydes?
Reduction
Decreases in o-h ratio
What causes oxidation of food what does it do?
Oxygen from air
Reacts with edible oils giving the food a rancid flavour
What are antioxidants?
Molecules which prevent these oxidation reactions taking place
Are reducing agents
Cause other substances to be reduced while being oxidised themselves
