QA: Test to Distinguish between Aqueous solution of Carbonates and Hydrogencarbonates of Group I
How to tell apart a carbonate from a hydrogen carbonate of Group I. A solution of Group I salt is prepared and then tested.
Learn the observations and the inferences that flashes.
| If pH is between 12-14 | Carbonate |
| If pH is between 7-8 | Hydrogencarbonate |
| If no change on boiling | Carbonate |
| CO2 evolved and pH increases to 12-14 on boiling | Hydrogencarbonate |
| Immediately forms white ppt at room temp. when adding an aqueous solution of Ca or Mg salt and boiling the mixture | Carbonate |
| A white ppt only forms on boiling when adding an aqueous solution of Ca or Mg salt and boiling the mixture | Hydrogencarbonate |