-
How do you test for ammonium ion? What is the result?
- NH4 +
- Add small amount of NaOH (aq)
- Place damp RED litmus paper into mouth of test tube.
- Warm gently.
- Litmus paper goes from red to blue. (means solution is alkali)
-
How do you test for a Chloride ion? Results?
- Cl -
- Add dilute HNO3 solution
- Add silver nitrate solution
- Solution goes white (precipitate)
- Add dilute ammonia and it AgCl will dissolve - leaving a colourless solution
-
How do you test for Bromide ions? Results
- Br -
- Add dilute HNO3 solution
- Add silver nitrate solution
- Solution goes creamy (precipitate)
- Add concentrated ammonia to give colourless solution
-
How do you test for Iodide ions? Results?
- I-
- Add dilute HNO3
- Add silver nitrate solution
- Goes from colourless to YELLOW (precipitate)
- AgI is too insoluble to react with ammonia, therefore, there will be no change even in addition of conc ammonia.
-
How do you test for sulfate ions? Results?
- SO4^2-
- Add dilute HCl
- Add Barium chloride
- Colourless to milky white
-
How do you test for Carbonate ions? Results?
- CO3^2-
- Set up delivery tube system
- Place solid or solution into T.T 1
- Add limewater to T.T 2
- Add dilute HCl to T.T 1 and quickly plug and allow gas to bubble into limewater.
- Limewater goes milky
-
How do you test for Magnesium ions? Result? What else must you do?
- Mg^2+
- Add sodium hydroxide
- Produce gelatinous white precipitate
- Calcium will do the same, so test in flame. If flame colour present (brick-red) then, it is Calcium, but if there is no flame colour, then it is Magnisium ion.
|
|
