oxidation of foods 2.2

Question 1

aldehydes

Answer 1

homologous series containing a carbonyl group at the end of a carbon chain

Question 2

ketones

Answer 2

homologous series containing a carbonyl group but cannot be at the end of a carbon chain

Question 3

carbonyl group

Answer 3

C = O

Question 4

3 types of alcohols

Answer 4

primary, secondary and tertiary

Question 5

primary alcohols

Answer 5

hydroxyl group attached to a carbon with at least 2 hydrogens

Question 6

secondary alcohols

Answer 6

hydroxyl group attached to a carbon with only 1 hydrogen

Question 7

tertiary alcohol

Answer 7

hydroxyl group attached to a carbon with no hydrogen

Question 8

oxidation of primary alcohols

Answer 8

primary alcohol to aldehyde to carboxylic acid

Question 9

oxidation of secondary alcohol

Answer 9

secondary alcohol to ketone

Question 10

oxidation of tertiary alcohol

Answer 10

tertiary alcohol to no reaction

Question 11

how to distinguish between aldehyde and ketones

Answer 11

using oxidising agents

Question 12

different oxidising agents

Answer 12

potassium dichromate, benedict’s (fehlings) reagent, hot copper (II) oxide and tollens reagent

Question 13

potassium dichromate

Answer 13

orange to green

Question 14

benedict’s (fehlings) reagent

Answer 14

blue to brick red

Question 15

hot copper (II) oxide

Answer 15

forms a brown solid

Question 16

tollens reagent

Answer 16

forms a silver mirror

Question 17

when does food become rancid

Answer 17

when edible oils present are oxidised

Question 18

how to stop food becoming rancid

Answer 18

when antioxidants are added, they are oxidised in place of the compounds they have been added to protect, they are reducing agents, many fruits have antioxidants eg vitamin C