How do you test for presence of ammonium ion?

Answer 1

add NaOH to the solution and gently warm, test the emerging gas with a litmus paper. it supposed to turn red litmus blue, also do not smell, ammonia is really really pungent.

Answer 2

To test for the presence of ammonium ions, you can use Nessler's reagent. Nessler's reagent forms a brown-colored complex with ammonium ions, which can be observed as a color change in the solution. Another common method is the addition of sodium hydroxide and then warming the solution, which releases ammonia gas that can be detected by its odor or by treating it with Nessler's reagent for a color change.