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A Level Chemistry test for unknowns

united4

Which order of tests would I do to identify the following solutions:

Acid
Iodide
Carbonate
Chloride
Nitrate

Reply 1

Pigster

Original post by united4

Which order of tests would I do to identify the following solutions:

Acid
Iodide
Carbonate
Chloride
Nitrate

What order would you do? Why?

Reply 2

Partypopcorn

I assume you mean what tests to identify each ion- Acid you could use either universal indicator, or one of the specific indicators used for a small pH range, which should be in the data book.
Iodide- use silver nitrate solution followed by ammonia solution. A yellow precipitate won’t dissolve= positive test
Carbonate- mix sample with hcl and bubble through limewater. Solution will turn cloudy as co2 is present.
Chloride- silver nitrate followed by ammonia. You’ll get a white precipitate that dissolves when ammonia is added.
Nitrate- not entirely sure on this one, but I think you add NaOH and then test on litmus paper.

Reply 3

Pigster

Original post by Partypopcorn

Nitrate- not entirely sure on this one, but I think you add NaOH and then test on litmus paper.

That'd be the test for ammonium ions (assuming you warm the mixture and test the gas given off with damp red litmus paper)

For nitrate, you add NaOH and powdered Al. Testing the gas in the same way - what with it also being NH3.