Negative Ion Tests

Negative Ion Tests

1. CARBONATE CO3 2-

   • TEST- add dilute hydrochloric acid to solid
     • RESULT - effervescence (fizzes), carbon dioxide produced (test with limewater).

2. CHLORIDE Cl- (in solution)

   • TEST- acidify solution with dilute nitric acid, then add aqueous silver nitrate
     • RESULT- white ppt of silver chloride formed: ppt soluble in ammonia solution

3. BROMIDE Br- (in solution)

   • TEST- acidify solution with dilute nitic acid, then add aqueous silver nitrate
     • RESULT- cream ppt of silver bromide formed: only slightly soluble in ammonia solution

4. IODIDE I- (In solution)

   • TEST- acidify solution with dilute nitric acid, then add aqueous silver nitrate
     • RESULT- yellow ppt of silver iodide formed: insoluble in ammonia solution

5. NITRATE N03- (In solution

   • TEST- make solution alkaline with sodium hydroxide solution, then add aluminium foil ( or Devarda's alloy) and warm carefully
     • RESULT- ammonia gas given off (test with moist red litmus)

6. SULFATE SO4 2- (In solution)

   • TEST- acidify solution with dilute hydrochloric acid, then add barium chloride solution OR acidify solution with dilute nitric acid, then add barium nitrate solution.
     • RESULT- white ppt of barium sulfate formed for both tests