tests for anions Flashcards
What is the test for carbonate (CO3 2–)?
- Add dilute nitric acid
2effervescence occurs bubble the gas through limewater, changing it from colourless to white precipitate (carbon dioxide)
This test indicates the presence of carbonates through the production of carbon dioxide gas.
What is the result of the test for chloride (Cl–)?
White precipitate forms (silver(I) chloride)
This test is used to confirm the presence of chloride ions.
What color precipitate forms when testing for bromide (Br–)?
Cream precipitate forms (silver(I) bromide)
The coloration indicates the presence of bromide ions in solution.
What color precipitate is observed when testing for iodide (I–)?
Yellow precipitate forms (silver(I) iodide)
This test confirms the presence of iodide ions.
What is the test for nitrate (NO3–)?
Add aqueous sodium hydroxide and aluminum foil, then warm carefully; gas produced turns damp red litmus paper blue (ammonia)
What result indicates the presence of sulfate (SO4 2–)?
White precipitate forms (barium sulfate) when acidified with dilute nitric acid and treated with aqueous barium nitrate or aqueous barium chloride
This confirms the presence of sulfate ions.
What test is used for sulfite (SO3 2–)?
Add dilute hydrochloric acid and warm gently; gas produced turns acidified potassium manganate (VII) from purple to colourless (sulfur dioxide)
What precipitate forms when lead(II) ions are added to iodide ions?
Bright yellow precipitate of lead(II) iodide forms
This test confirms the presence of iodide ions using lead(II) cations.
How to test for a sulfate ion
- acidify with dilute nitric acid
- add aqueous barium nitrate or chloride
- White precipitate is formed ( barium sulfate)
What is added to test for halide ions
Acidify with dilute nitric acid then add silver nitrate
What precipitate forms when lead(II) ions are added to chloride?
White precipitate of lead (ll) chloride
What precipitate forms when lead(II) ions are added to Bromide ions?
White precipitate of lead(ll) bromide
