Functional Group Tests

Question 1

Test for alkenes

Answer 1

Bromine water, orange to colourless

Question 2

Test for carboxylic acids

Answer 2

Add sodium carbonate and test gas with limewater, bubbles ,limewater turns clear to cloudy

Question 3

Test for halogenoalkanes

Answer 3

Heat with aqueous sodium hydroxide and ethanol, then test for halide ion

Question 4

Test for chloride ions

Answer 4

Add nitric acid and silver nitrate soloution, white precipitate

Question 5

Test for bromide ions

Answer 5

Add nitric acid and silver nitrate soloution, cream precipatate

Question 6

Test for iodine ions

Answer 6

Add nitric acid and silver nitrate soloution, yellow precipitate

Question 7

Test for aldehydes

Answer 7

Fehling’s solution, blue to red preciptate. Or Tollen’s reagent, silver mirror

Question 8

Test for primary alcohols

Answer 8

Add acidified potassium dichromate, orange to green

Question 9

Test for secondary alcohols

Answer 9

Add acidified potassium dichromate, orange to green

Question 10

Test for teirary alcohols

Answer 10

Add acidified potassium dichromate, no visible change