QA Test for Anions

Question 1

Method for NO3- (nitrate)

Answer 1

1. Add dilute NaOH (aq)
2. Add a piece of aluminium foil/powder
3. Warm mixture and test gas liberated (NH3) with a piece of moist red litmus paper

Question 2

Observation for NO3- (nitrate)

Answer 2

Ammonia is liberated; moist red litmus paper turns blue

Question 3

Method for CO3 2- (carbonate)

Answer 3

1. Add dilute HCl/any acid
2. Bubble gas into limewater

Question 4

Observation for CO3 2- (carbonate)

Answer 4

Carbon dioxide is liberated; effervescence is produced, white precipitate is formed in limewater

Question 5

Method for Cl- (chloride)

Answer 5

1. Add dilute nitric acid
2. Add silver/lead (II) nitrate

Question 6

Observation for Cl- (chloride)

Answer 6

White precipitate of silver/lead (II) chloride is formed

Question 7

Method for I- (iodide)

Answer 7

1. Add dilute nitric acid
2. Add silver/lead (II) nitrate
   (Same as chloride)

Question 8

Observation for I- (iodine)

Answer 8

Yellow precipitate of silver/lead (II) iodide formed

Question 9

Method for SO4 2- (sulfate)

Answer 9

1. Add dilute nitric acid
2. Add barium/ calcium chloride/ nitrate

Question 10

Observation for SO4 2- (sulfate)

Answer 10

White precipitate of barium/calcium sulfate is formed