Unit 2 Oxidation of food

Question 1

Aldehydes

Answer 1

CnH2n+1 CHO
Ends in -al
Contain carbonyl function group

Question 2

Ketones

Answer 2

Contain carbonyl function group
Ends in -one

Question 3

O:H Ratio

Answer 3

Oxidation can be achieved by adding an O or removal of H- Increases O:H Ratio
Reduction is a decrease of O:H Ratio

Question 4

Oxidation of primary alcohols

Answer 4

Alcohol–> Aldehyde–> Carboxylic acid

Question 5

Oxidation of secondary alcohols

Answer 5

Alcohol–> Ketone

Question 6

Oxidation of tertiary alcohols

Answer 6

Cannot be oxidised

Question 7

Oxidising agents

Answer 7

Hot copper (II) oxide (Black to brown)
Acidified Dichromate (IV) (Orange to green)

Question 8

How do you differentiate the difference between Aldehydes and Ketones by testing

Answer 8

Fehling solution- Blue to Brick red in presence of Aldehydes
Tollens- Forms silver mirror in Aldehydes
Acidified Dichromate- Orange to green in presence of Aldehydes

Question 9

What causes rancid flavours in food

Answer 9

Oxidation of edible oils

Question 10

Antioxidants

Answer 10

Molecules that prevent unwanted oxidation reactions from occurring.
Easily oxidised and are oxidised in place of the compound.