Unit 2 - Oxidation Of Foods

Question 1

Acidified dichromate(VI) solution can be used to oxidise………

Answer 1

Primary alcohols to aldehydes and then to carboxylic acid

Secondary alcohols to ketones

Question 2

What colour does black copper (II) oxide go in these reactions?

Answer 2

Brown

Question 3

Can tertiary alcohols be oxidised using hot copper oxide or acidified dichromate solutions

Answer 3

NO

Question 4

What groups do both aldehydes and ketones poses?

Answer 4

They contain a carbonyl functional group

Question 5

NOTE
Straight chain and branched aldehydes and ketones can be systematically named from structural formulae containing no more than 8 carbons in the longest chain

Answer 5

Xxxxxx

Question 6

Can aldehydes be oxidised again

Answer 6

Yes. They can be oxidised to carboxylic acids

Question 7

Can ketones be oxidised again

Answer 7

NO.

Question 8

Note

Oxidising agents can be used to differentiate between an aldehydes and a ketone.

Answer 8

Xxxxxx

Question 9

Note

Oxygen from the air causes the oxidation of food. The oxidation of food gives a rancid flavour

Answer 9

Xxxxxx

Question 10

What are antioxidants

Answer 10

Molecules that prevent unwanted oxidation reactions occurring
• Substances that are easily oxidised, and oxidise in place of the compounds they have been added to protect
• can be identified as the substance oxidised in a redox equation