Testing for Anions

Question 1

Test for carbonate (CO3²-) method

Answer 1

Add dilute acid

Question 2

Test for carbonate (CO3²-) positive result

Answer 2

Effervescence, carbon dioxide produced

Question 3

Test for chloride (Cl-) in solution

Answer 3

Acidify with dilute nitric acid, then add aqueous silver nitrate

Question 4

Test for chloride (Cl-) positive result

Answer 4

White precipitate

Question 5

Test for bromide (Br-) in solution

Answer 5

Acidify with dilute nitric acid, then add aqueous silver nitrate

Question 6

Test for bromide (Br-) positive result

Answer 6

Cream precipitate

Question 7

Test for iodide (I-) in solution

Answer 7

Acidify with dilute nitric acid, then add aqueous silver nitrate

Question 8

Test for iodide (I-) positive result

Answer 8

yellow precipitate

Question 9

Test for nitrate (NO3 -) in solution

Answer 9

Add aqueous sodium hydroxide, then aluminium foil; warm carefully

Question 10

Test for nitrate (NO3 -) positive result

Answer 10

Ammonia produced

Question 11

Test for sulfate (SO4²-) in solution

Answer 11

Acidify, then add aqueous barium nitrate

Question 12

Test for sulfate (SO4²-) positive result

Answer 12

White precipitate

Question 13

Test for sulfite (SO3²-)

Answer 13

Add dilute hydrochloric acid, warm gently and test for the presence of sulfur dioxide

Question 14

Test for sulfite (SO3²-) positive result

Answer 14

Sulfur dioxide produced will turn acidified aqueous potassium manganate (VII) from purple to colourless