carbonates, halides and sulfates ( anions )

Test tube reactions can also be carried out to identify the negative ion ( anion ) present in a compound. There are 5 different ions that there is a test for which can confirm if it is presents in a compound.

CARBONATE

Test:

  1. Add lime water to a test tube

  2. Add HCl and sodium carbonate to a boiling tube

  3. Set up a bung and delivery tube between them

There should be effervescence in the boiling tube and the limewater should turn cloudy ( white precipitate )

CHLORIDE, BROMIDE AND IODIDE ( HALIDES )

Test:

  1. Add 1cm of sodium chloride/bromide/iodide into a test tube Add

  2. Add 1cm of nitric acid into the test tube

  3. Add silver nitrate drop by drop

For chloride a white precipitate should form, for bromide cream and for iodide yellow

SULFATE

Test:

  1. Add 1cm of sodium sulfate into test tube

  2. Add 1 cm of HCl into same test tube

  3. Add barium chloride drop by drop

The solution should turn cloudy meaning a white precipitate