Tests for Anions, Cations and Gases

What is an anion?

• a positive ion

• a negative ion

• a dsylexic onion

What is a cation?

• a positive ion

• a negative ion

• an electrically charged cat

What is the test for a carbonate ion (CO₃^2-)?

• add an acid - effervescence and CO₂ is produced

• acidify with nitric acid and add silver nitrate - white ppt is formed

• add NaOH and then aluminium foil - ammonia is produced

• acidify and add barium nitrate - White ppt is formed

What is the test for a Chloride ion (Cl^-)?

• add an acid - effervescence and CO₂ is produced

• acidify with nitric acid and add silver nitrate - white ppt is formed

• add NaOH and then aluminium foil - ammonia is produced

• acidify and add barium nitrate - White ppt is formed

What is the test for a Sulphate ion (SO₄^2-)?

• add an acid - effervescence and CO₂ is produced

• acidify with nitric acid and add silver nitrate - white ppt is formed

• add NaOH and then aluminium foil - ammonia is produced

• acidify and add barium nitrate - White ppt is formed

What is a precipitate?

• An insoluble solid formed in a reaction

• when you sweat a lot

• When it rains

• A soluble solid formed in a reaction

What is the postive test result when ammonia (NH₄⁺) is added to NaOH?

• ammonia is produced on warming

• White ppt is formed

• Light blue ppt is formed

• Green ppt is formed

What is the postive test result when a calcium ion (Ca²⁺) is added to NaOH or aqueous ammonia?

• ammonia is produced on warming

• White ppt is formed

• Light blue ppt is formed

• Green ppt is formed

What is the postive test result when a copper ion (Cu²⁺) is added to NaOH or aqueous ammonia?

• ammonia is produced on warming

• White ppt is formed

• Light blue ppt is formed (forms a dark blue solution)

• Green ppt is formed

What is the postive test result when a iron (II) ion (Fe²⁺) is added to NaOH or aqueous ammonia?

• ammonia is produced on warming

• White ppt is formed

• Light blue ppt is formed (forms a dark blue solution)

• Green ppt is formed